[go: up one dir, main page]

WO2011114709A1 - Batterie secondaire au lithium - Google Patents

Batterie secondaire au lithium Download PDF

Info

Publication number
WO2011114709A1
WO2011114709A1 PCT/JP2011/001502 JP2011001502W WO2011114709A1 WO 2011114709 A1 WO2011114709 A1 WO 2011114709A1 JP 2011001502 W JP2011001502 W JP 2011001502W WO 2011114709 A1 WO2011114709 A1 WO 2011114709A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
negative electrode
positive electrode
lithium secondary
secondary battery
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2011/001502
Other languages
English (en)
Japanese (ja)
Inventor
秀治 武澤
朝樹 塩崎
泰右 山本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Corp
Original Assignee
Panasonic Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Panasonic Corp filed Critical Panasonic Corp
Publication of WO2011114709A1 publication Critical patent/WO2011114709A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/387—Tin or alloys based on tin
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a lithium secondary battery, particularly a lithium secondary battery containing an alloy-based active material.
  • Lithium secondary batteries have high capacity and high energy density, and can be easily reduced in size and weight.
  • mobile phones personal digital assistants (PDAs), notebook personal computers, video cameras, portable game machines, etc. It is widely used as a power source for portable electronic devices.
  • PDAs personal digital assistants
  • portable small electronic devices further multi-functionalization has been promoted, and continuous use time has been required to be extended.
  • lithium secondary batteries are expected not only as a power source for small electronic devices but also as a power source for large devices such as hybrid cars, electric vehicles, and electric tools. In order to meet these demands, it is necessary to further increase the capacity of lithium secondary batteries used as power sources.
  • a lithium secondary battery includes a substrate (current collector), a negative electrode including a negative electrode active material layer (negative electrode active material layer) formed on the substrate, a substrate (current collector), The positive electrode comprised from the layer (positive electrode active material layer) containing the positive electrode active material formed on the board
  • Patent Document 1 discloses the use of silicon, tin, oxides thereof, nitrides thereof, compounds containing them, alloys, and the like as a high-capacity negative electrode active material.
  • a separator including a porous heat-resistant layer.
  • the negative electrode active material when an alloy containing silicon or tin is used as the negative electrode active material, there are the following problems.
  • the alloy-based active material has a large volume expansion / contraction due to insertion / extraction of lithium ions. For this reason, if charging / discharging is repeated, there is a possibility that current collection failure may occur between the substrate and the negative electrode active material layer, or the negative electrode may be flawed or broken. These are factors that deteriorate the charge / discharge cycle characteristics of the lithium secondary battery.
  • Patent Document 2 proposes that a negative electrode active material film is formed by directly depositing a negative electrode active material on a substrate having an uneven surface by a vapor phase method such as sputtering.
  • the negative electrode active material film is separated into a plurality of columnar active material bodies by charging and discharging while maintaining the current collecting property with the substrate.
  • Patent Document 3 proposes using a substrate having a plurality of convex portions and forming a negative electrode active material only on the convex portions.
  • Patent Document 3 a plurality of resist patterns are formed on a substrate, and copper and a negative electrode active material are deposited thereon. Next, the resist pattern and the copper and negative electrode active material thereon are removed by lift-off. Thereby, while forming the convex part which consists of copper on a board
  • the present invention has been made in view of the above circumstances, and an object thereof is to suppress deterioration of the negative electrode and the positive electrode due to repeated charge and discharge in a lithium secondary battery using an alloy containing silicon or tin as a negative electrode active material. Thus, the charge / discharge cycle characteristics are improved.
  • the lithium secondary battery of the present invention includes a positive electrode having a positive electrode active material capable of occluding and releasing lithium ions, a negative electrode having a negative electrode active material capable of occluding and releasing lithium ions, and a gap between the positive electrode and the negative electrode.
  • a lithium secondary battery comprising a separator disposed and an electrolyte having lithium ion conductivity, wherein the negative electrode has a negative electrode current collector having a plurality of protrusions on the surface, and the negative electrode current collector.
  • a negative electrode active material layer including a plurality of active material bodies formed, and each of the plurality of active material bodies is disposed on each convex portion of the negative electrode current collector, and silicon or An alloy-based active material containing tin is included, and a porous insulating layer mainly composed of an inorganic oxide is further provided between the positive electrode and the negative electrode.
  • the lithium secondary battery of the present invention uses an alloy-based active material containing silicon or tin as a negative electrode active material, the energy density is high.
  • the plurality of active material bodies including the negative electrode active material are disposed on the respective convex portions on the surface of the current collector, the stress accompanying expansion and contraction of the negative electrode active material can be relaxed.
  • a porous insulating layer mainly composed of an inorganic oxide is provided between the positive electrode and the negative electrode, the stress generated in the positive electrode active material layer due to the volume change of the negative electrode can be reduced, and the positive electrode active material can be prevented from falling off. Can do. Therefore, it is possible to suppress a decrease in the positive electrode capacity due to the falling off of the positive electrode active material.
  • the present invention not only the deterioration of the negative electrode but also the deterioration of the positive electrode caused by the volume change of the negative electrode active material can be suppressed, so that the charge / discharge cycle characteristics can be improved.
  • FIG. 1 It is sectional drawing which shows typically the electrode group in the lithium secondary battery 100 of embodiment by this invention.
  • (A) And (b) is typical sectional drawing for demonstrating the stress concerning a positive electrode in the conventional lithium secondary battery using the negative electrode which has a columnar structure, (a) is before charging. (During discharging), (b) shows the state during charging.
  • (A) And (b) is typical sectional drawing for demonstrating the stress concerning a positive electrode in the lithium secondary battery using the negative electrode of 1st Embodiment by this invention, (a) is charge. Before performing (when discharging), (b) shows the state during charging.
  • (A) And (b) is typical sectional drawing for demonstrating the stress concerning a positive electrode in the conventional lithium secondary battery using the negative electrode which does not have a columnar structure, (a) performs charge. The previous (during discharging) and (b) show the state during charging, respectively.
  • (A)-(c) is typical sectional drawing for demonstrating the mechanism in which electrolyte solution reduces by charging / discharging in the conventional lithium secondary battery provided with the negative electrode which has a columnar structure, respectively.
  • (A)-(c) is typical sectional drawing for demonstrating the effect acquired by arrange
  • FIG. 3 is an enlarged cross-sectional view schematically showing an active material body included in a negative electrode active material layer in a lithium secondary battery 200.
  • FIG. 3 is a perspective view schematically showing an example of a negative electrode current collector in a lithium secondary battery 200.
  • FIG. 4 is an enlarged cross-sectional view schematically showing an active material body included in another negative electrode active material layer in the lithium secondary battery 200.
  • FIG. 2 is a cross-sectional view schematically showing a configuration of an electron beam evaporation apparatus 50.
  • FIG. 3 is a schematic cross-sectional view showing a configuration of an electrode group (a porous insulating layer is formed on the surface of a positive electrode) in the lithium secondary batteries of Examples 1 to 4, 6, and 7.
  • 6 is a schematic cross-sectional view showing a configuration of an electrode group (a porous insulating layer is formed on a separator surface) in a lithium secondary battery of Example 5.
  • FIG. FIG. 4 is a schematic cross-sectional view showing a configuration of an electrode group (having no porous insulating layer) in lithium secondary batteries of Comparative Examples 1 to 3.
  • (A) And (b) is a figure for demonstrating the charging / discharging cycling characteristics of the conventional lithium secondary battery.
  • the present inventor repeated diligent studies to further improve the charge / discharge cycle characteristics in a conventional lithium secondary battery including a negative electrode having a columnar structure. As a result, it was found that not only the negative electrode but also the positive electrode deteriorated by repeated charge and discharge. In particular, it has also been found that the positive electrode may be greatly deteriorated as compared with the case where a negative electrode having no columnar structure is used.
  • FIG. 16A and 16 (b) are diagrams illustrating results of measuring charge / discharge cycle characteristics of a conventional lithium secondary battery.
  • a graph 71 shows charge / discharge cycle characteristics of a lithium secondary battery (referred to as “battery II”) using carbon (C) as a negative electrode active material
  • a graph 72 shows a negative electrode active material.
  • the charge / discharge cycle characteristics of a lithium secondary battery (referred to as “battery I”) using silicon oxide (SiOx) are shown.
  • As the positive electrode active material a nickel acid positive electrode material is used.
  • graph 73 and graph 75 show the charge / discharge cycle characteristics of the negative electrode and the positive electrode (changes in negative electrode capacity and positive electrode capacity accompanying the charge / discharge cycle), respectively, in the battery II.
  • graph 74 and graph 76 show the charge / discharge cycle characteristics of the negative electrode and the positive electrode in Battery I, respectively.
  • the battery I using silicon oxide having a large volume change associated with insertion and extraction of lithium as the negative electrode active material is more effective than the battery II using carbon.
  • the charge / discharge cycle characteristics of the graph are degraded (graphs 71 and 72).
  • the positive electrode is deteriorated in addition to the negative electrode as the charge / discharge cycle is repeated (graphs 74 and 76).
  • the deterioration of the negative electrode of the battery I is larger than the deterioration of the negative electrode of the battery II. This is considered because the negative electrode of the battery I is more easily deteriorated due to the volume change of the silicon oxide.
  • the deterioration of the positive electrode of the battery I is larger than the deterioration of the positive electrode of the battery II.
  • the cause of the deterioration of the positive electrode of the battery I is considered as follows.
  • the negative electrode active material greatly expands and contracts with charge and discharge.
  • the volume change of each active material body is further increased. This volume change of the active object gives local stress to the positive electrode active material layer, and as a result, the positive electrode active material layer is likely to fall off partially.
  • the positive electrode active material is generally composed of a material having a lower strength than the negative electrode active material, and is easily dropped or deformed. When the positive electrode active material layer falls off, the positive electrode capacity decreases, which causes a decrease in battery capacity.
  • the negative electrode does not have a columnar structure
  • the deterioration of the negative electrode capacity (decrease in the negative electrode capacity) is large, so the decrease in charge / discharge cycle characteristics of the battery is mainly due to the decrease in the negative electrode capacity. Is hardly a problem.
  • the negative electrode has a columnar structure
  • the deterioration of the negative electrode is suppressed to some extent, and the positive electrode capacity is greatly reduced as the volume change of the negative electrode increases. For this reason, the deterioration of the positive electrode becomes obvious, and the possibility of becoming one of the main factors that deteriorate the charge / discharge cycle characteristics of the battery increases. Therefore, in order to improve the charge / discharge cycle characteristics of the battery, it is more important to suppress the decrease in the positive electrode capacity.
  • the present inventor has repeatedly studied a battery structure that suppresses deterioration of the positive electrode. As a result, it has been found that by providing a porous insulating layer mainly composed of an inorganic oxide between the positive electrode and the negative electrode, the stress applied to the positive electrode active material layer due to the volume change of the negative electrode can be reduced. It came.
  • FIG. 1 is a schematic cross-sectional view of a lithium secondary battery 100 of the present embodiment.
  • the lithium secondary battery 100 of this embodiment includes a negative electrode 20, a positive electrode 30, a separator 13 disposed between the negative electrode 20 and the positive electrode 30, a porous insulating layer 15, and an electrolytic solution having lithium ion conductivity.
  • the negative electrode 20 includes a negative electrode current collector 21 having a plurality of protrusions 22 on the surface, and a negative electrode active material layer 23 formed on the surface of the negative electrode current collector 21.
  • the positive electrode 30 includes a positive electrode current collector 31 and a positive electrode active material layer 33 formed on the surface of the positive electrode current collector 31. The positive electrode 30 and the negative electrode 20 are disposed so that the negative electrode active material layer 23 and the positive electrode active material layer 33 are opposed to each other with the separator 13 interposed therebetween.
  • the porous insulating layer 15 is provided between the positive electrode active material layer 33 and the negative electrode active material layer 23.
  • the porous insulating layer 15 contains an inorganic oxide as a main component, and has lithium ion permeability and insulating properties during normal use of a lithium secondary battery.
  • the negative electrode active material layer 23 has a plurality of columnar active material bodies 24 arranged on the convex portions 22 of the negative electrode current collector 21.
  • the active material body 24 includes an alloy-based active material containing silicon or tin as a negative electrode active material. It is preferable that the active material bodies 24 are arranged at intervals (spaces 26) from each other during discharge. In addition, when each active material body 24 expand
  • porous insulating layer 15 in this embodiment is sufficiently hard because it is mainly composed of an inorganic oxide, and reduces the stress applied to the positive electrode active material layer 33 by the volume change of the negative electrode active material. Functions as a buffer layer. Therefore, according to this embodiment, it is possible to suppress the deterioration of the positive electrode due to the volume change of the negative electrode.
  • FIG. 2 is a schematic cross-sectional view for explaining the stress applied to the positive electrode in a conventional lithium secondary battery using a negative electrode having a columnar structure.
  • FIG. 3 is a schematic cross-sectional view for explaining the stress applied to the positive electrode in the lithium secondary battery of this embodiment.
  • (A) in each figure shows a state before charging (during discharging), and (b) in each figure shows a state during charging.
  • each active material body 24 absorbs lithium and expands, and adjacent active material bodies. 24 come into contact with each other.
  • Each active material body 24 also expands in the thickness direction and applies mechanical stress to the separator 13.
  • Such expansion stress of the active material body 24 is transmitted to the positive electrode active material layer 33 through the separator 13.
  • the portion 33p located above the active material body 24 in the positive electrode active material layer 33 is pressed, and stress (mechanical stress) s1 is generated.
  • the positive electrode active material is likely to fall off.
  • the porous insulating layer 15 is disposed between the positive electrode 30 and the separator 13.
  • the expansion stress is transmitted to the porous insulating layer 15 via the separator 13.
  • the porous insulating layer 15 is mainly composed of an inorganic oxide and is sufficiently hard, the expansion stress from the negative electrode 20 side is dispersed by the porous insulating layer 15.
  • the stress s2 transmitted to the positive electrode active material layer 33 is smaller than the stress s1 transmitted to the positive electrode active material layer 33 in the conventional lithium secondary battery. Accordingly, it is possible to suppress the loss of the positive electrode active material due to the volume change of the negative electrode 20 as compared with the conventional case, and it is possible to suppress the decrease in the positive electrode capacity due to the drop of the positive electrode active material.
  • the stress applied to the positive electrode active material layer 33 due to the volume change of the negative electrode active material can be reduced. Therefore, since the deterioration of the positive electrode 30 due to repeated charge / discharge can be suppressed as compared with the conventional case, the charge / discharge cycle characteristics can be improved.
  • FIGS. 4A and 4B are schematic cross-sectional views for explaining the stress applied to the positive electrode in a conventional lithium secondary battery using a negative electrode having no columnar structure. Show.
  • the negative electrode active formed on the negative electrode 121 is started when charging is started.
  • the material layer 123 absorbs lithium and expands in the thickness direction.
  • the negative electrode active material layer 123 expands greatly, and the mechanical stress is applied to the positive electrode active material layer 33.
  • This mechanical stress (stress) is substantially uniformly applied to the entire surface of the positive electrode active material layer 33, unlike the stresses s1 and s2 shown in FIGS. Since the positive electrode active material layer 33 is not partially pressed (unevenly pressed), it is considered that the positive electrode active material does not easily fall off.
  • the negative electrode 20 itself is largely deteriorated due to the expansion of the negative electrode active material, so that the problem of deterioration of the positive electrode 30 does not become obvious.
  • the negative electrode active material layer 123 has a small expansion coefficient, so that the problem of deterioration of the negative electrode 20 and the positive electrode 30 due to the expansion stress of the negative electrode active material does not occur. From this, the deterioration of the positive electrode 30 due to the volume change of the negative electrode active material is a problem peculiar to the lithium secondary battery including the negative electrode 20 including the negative electrode active material containing silicon or tin and having the columnar structure. I understand.
  • the porous insulating layer 15 is preferably harder than the separator 13. Thereby, the function as a buffer layer can be exhibited more effectively.
  • the porous insulating layer 15 is disposed between the positive electrode active material layer 33 and the separator 13, but the position of the porous insulating layer 15 is not limited to the illustrated position. If the porous insulating layer 15 is disposed between the positive electrode active material layer 33 and the negative electrode active material layer 23, the above effect can be obtained. In addition, the porous insulating layer 15 may be formed on at least a part of a portion located between the positive electrode active material layer 33 and the negative electrode active material layer 23 in a plane parallel to the negative electrode current collector 21. . However, it is preferable to be formed over the entire portion because dropping of the positive electrode active material from the positive electrode active material layer 33 can be more effectively suppressed.
  • the thickness of the porous insulating layer 15 is preferably 1 ⁇ m or more. If thickness is 1 micrometer or more, since the stress from a negative electrode side can be relieve
  • the negative electrode active material layer 23 should just be comprised from the active material body 24 formed on each convex part 22 of the electrical power collector 21.
  • FIG. it is preferable that a space is formed between the adjacent active material bodies 24 during discharge.
  • swells by occlusion of lithium can be ensured, the peeling of the negative electrode active material and the deformation
  • the expansion in the thickness direction can be reduced by the amount that each active material body 24 expands in the lateral direction during charging, the stress applied to the positive electrode active material layer 33 can be reduced.
  • the volume change of the active material body 24 means (volume of active material body during charging ⁇ volume of active material body during discharge) / volume (%) of active material body during discharge.
  • the volume change of the active material body 24 is preferably 200% or more, for example.
  • the porous insulating layer 15 is inferior to the separator (resin separator) 13, it has a high insulating property and an excellent ion permeability, and thus has a function as a separator. Therefore, even if the porous insulating layer 15 is disposed between the positive electrode 30 and the negative electrode 20, the movement of the electrolytic solution is not hindered, so that the effects as described above can be obtained while maintaining the battery performance. .
  • the inorganic oxide has high chemical stability. It is possible to prevent the surface of the positive electrode side from being oxidized. Accordingly, it is possible to suppress an increase in resistance due to the surface alteration of the separator 13.
  • Electrolytic solution retention effect of porous insulating layer 15 The surface of the porous insulating layer 15 has higher wettability with respect to the electrolytic solution than the surface of the positive electrode 30 (here, the surface of the positive electrode active material layer 33). Preferably it is. Thereby, it has the function to hold
  • porous insulating layer 15 can suppress the decrease in the electrolyte along with the problems in the conventional lithium secondary battery along with the problems in the conventional lithium secondary battery will be described in detail with reference to the drawings.
  • the present inventor has found that the conventional lithium secondary battery has a problem that the electrolyte solution on the positive electrode side gradually decreases due to repeated charge and discharge, resulting in a decrease in capacity and a decrease in charge / discharge cycle characteristics. It was. This is presumably because a phenomenon occurs in which the electrolyte solution on the positive electrode side gradually decreases when charging and discharging are repeated. This phenomenon is particularly noticeable in a lithium secondary battery using a negative electrode having a columnar structure, and is considered to be one of the factors that make it difficult to further improve the charge / discharge cycle characteristics.
  • FIG. 5A is a cross-sectional view showing a state of the lithium secondary battery before charging.
  • the lithium secondary battery includes a negative electrode 20, a separator 13, and a positive electrode 30 disposed to face the negative electrode 20 with the separator 13 interposed therebetween.
  • the negative electrode 20 includes a current collector 21 and a negative electrode active material layer 23 formed on the surface of the current collector 21.
  • the negative electrode active material layer 23 is composed of a plurality of columnar active material bodies (active material bodies) 24.
  • an electrolyte solution exists between the positive electrode 30 and the negative electrode 20.
  • the plurality of active material bodies 24 are arranged at intervals. For this reason, the electrolytic solution enters the space 26 between the active material bodies 24.
  • each active material member 24 expands by absorbing lithium, and adjacent active material members 24 come into contact with each other. As a result, there is almost no space between the active material bodies 24, and the negative electrode active material layer 23 becomes a continuous film. Since each active material body 24 expands not only in the width direction of the active material body 24 but also in the height direction, the thickness of the negative electrode active material layer 23 also increases. For this reason, a part of the electrolytic solution that has entered the space 26 of the active material body 24 is discharged out of the system (arrow 45).
  • inside system a region sandwiched between the positive electrode active material layer 33 and the negative electrode active material layer 23 is referred to as “inside system”, and a region other than the above region in the lithium secondary battery is referred to as “outside system”.
  • each active material body 24 contracts, and a space 26 is formed between the adjacent active material bodies 24.
  • the amount of the electrolyte solution on the negative electrode side is smaller than that during the previous discharge (FIG. 5A). This is because the electrolyte discharged outside the system at the time of charging is difficult to return to the system even after discharging. Moreover, since the electrolyte solution on the negative electrode side is consumed by the side reaction of the negative electrode 20, it further decreases.
  • the above-mentioned “side reaction” includes a reaction in which the electrolytic solution undergoes reductive decomposition on a new surface exposed by cracking.
  • the negative electrode active material itself and the electrolytic solution directly react with each other to include a reaction in which the negative electrode active material is altered (oxidation or the like).
  • the amount of the electrolytic solution in the system gradually decreases.
  • the reaction occurs non-uniformly in the positive electrode 30 and the deterioration proceeds.
  • the porous insulating layer 15 having high wettability is disposed between the positive electrode 30 and the negative electrode 20, the electrolytic solution is difficult to move from the positive electrode 30 to the negative electrode 20, and as a result, the positive electrode The decrease of the electrolyte solution on the side can be suppressed.
  • FIG. 6A to 6C are schematic cross-sectional views showing a lithium secondary battery according to an embodiment of the present invention.
  • FIG. 6A shows a state before charging (during discharging)
  • FIG. 6 (c) shows a state where the battery is discharged again after being charged as shown in FIG. 6 (b).
  • convex portions on the surface of the negative electrode current collector 21 are omitted.
  • each active material member 24 absorbs lithium and expands.
  • adjacent active material bodies 24 are in contact with each other.
  • the thickness of the negative electrode active material layer 23 also increases.
  • the thickness of the negative electrode active material layer 23 before charging is t
  • the thickness of the negative electrode active material layer 23 is t + ⁇ t by charging.
  • a part of the electrolytic solution that has entered the space 26 of the active material body 24 flows out of the system as indicated by an arrow 41. For this reason, the electrolyte solution on the negative electrode side decreases by the amount that flows out of the system.
  • the next discharge is started in a state where the electrolyte solution on the negative electrode side is insufficient, and a space 26 is formed again between the active material bodies 24.
  • the porous insulating layer 15 having a surface with higher wettability than the surface of the positive electrode 30 is disposed between the positive electrode 30 and the negative electrode 20. For this reason, even if the space 26 is formed in a state where the electrolyte solution on the negative electrode side is reduced, the electrolyte solution on the positive electrode side is held by the porous insulating layer 15 and hardly moves to the negative electrode side.
  • the porous insulating layer 15 by providing the porous insulating layer 15, it is possible to suppress the movement of the electrolyte solution from the positive electrode side to the negative electrode side, thereby suppressing the decrease in the electrolyte solution on the positive electrode side due to charge / discharge. Can do. Therefore, the deterioration of the positive electrode due to repeated charge / discharge can be suppressed more than before. In addition, since a part of the electrolytic solution that flows out of the system during charging is easily returned to the system, a decrease in the amount of the electrolytic solution in the system is also suppressed. Therefore, the charge / discharge cycle characteristics can be further improved as compared with the prior art.
  • the porous insulating layer 15 preferably has a higher porosity (porosity) than the separator 13. Assuming that the thickness T ′ of the separator 13 in the conventional lithium secondary battery shown in FIG. 5 is equal to the total thickness T of the separator 13 and the porous insulating layer 15 in the present embodiment, the porous insulating layer 15 is empty. By making the porosity higher than the porosity of the separator 13, it is possible to reduce the amount of the electrolyte flowing out of the system during charging. Therefore, it is possible to more effectively suppress the decrease in the electrolyte solution in the system.
  • the ratio of the thickness of the porous insulating layer 15 to the thickness of the separator 13 is preferably 5% or more, for example. Thereby, since the movement of the electrolyte solution from the positive electrode side to the negative electrode side can be more reliably suppressed, the charge / discharge cycle life can be improved more effectively. Moreover, it is preferable that the said ratio is 40% or less, for example. Thereby, the capacity
  • the porous insulating layer 15 Since the porous insulating layer 15 mainly composed of inorganic oxide has a melting point higher than that of the separator 13, it is stable even at a high temperature. For this reason, since it is harder to dissolve than the separator 13, it is possible to prevent physical contact between the positive electrode active material layer 33 and the negative electrode active material layer 23 even when heat is generated.
  • the porous insulating layer 15 may be a porous layer mainly composed of an inorganic oxide and having insulating properties. For example, it may be formed using an inorganic oxide and a binder.
  • the porous insulating layer 15 may have heat resistance.
  • a porous insulating layer 15 can be formed using, for example, an inorganic oxide and a heat resistant resin.
  • the specific surface area of the negative electrode active material is large, which may further increase the heat generation rate.
  • the porous insulating layer 15 has heat resistance, not only the movement of the electrolytic solution can be suppressed, but also the progress of the internal short circuit can be suppressed when an internal short circuit occurs. Therefore, in addition to the charge / discharge cycle characteristics of the lithium secondary battery, safety can be improved more effectively.
  • FIG. 7 is a cross-sectional view schematically showing an example of the lithium secondary battery of the present embodiment.
  • the illustrated example is a coin-type lithium secondary battery.
  • the same components as those in FIG. 7 are identical to FIG. 7 and are identical to FIG. 7 .
  • the lithium secondary battery 200 includes an electrode group in which a positive electrode 30, a porous insulating layer 15, a separator 13, and a negative electrode 20 are stacked, a positive electrode lead 18 connected to the positive electrode 30, and a negative electrode lead 19 connected to the negative electrode 20.
  • the positive electrode 30 includes a positive electrode current collector 31 and a positive electrode active material layer 33.
  • the positive electrode current collector 31 those commonly used in this field can be used.
  • a porous or non-porous conductive substrate made of a metal material such as stainless steel, titanium, or aluminum or a conductive resin can be used.
  • the porous conductive substrate include a mesh body, a net body, a punching sheet, a lath body, a porous body, a foam, a fiber group molded body (nonwoven fabric, etc.), and the like.
  • the non-porous conductive substrate include a foil, a sheet, and a film.
  • the thickness of the porous or non-porous conductive substrate is not particularly limited, but is, for example, 1 to 500 ⁇ m, preferably 1 to 50 ⁇ m, more preferably 10 to 40 ⁇ m, and particularly preferably 10 to 30 ⁇ m.
  • the positive electrode active material layer 33 contains a positive electrode active material. Moreover, the electrically conductive agent and the binder may be contained as needed.
  • the positive electrode active material is not particularly limited as long as it is a material that can occlude and release lithium ions, but lithium-containing composite metal oxides, olivine-type lithium phosphate, and the like can be preferably used.
  • the lithium-containing composite metal oxide is a metal oxide containing lithium and a transition metal or a metal oxide in which a part of the transition metal in the metal oxide is substituted with a different element.
  • examples of the different element include Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb, and B.
  • Mn, Al, Co, Ni, Mg, etc. are preferable.
  • One kind or two or more kinds of different elements may be used.
  • m value which shows the molar ratio of lithium is a value immediately after positive electrode active material preparation, and increases / decreases by charging / discharging.
  • M, x, m and n are the same.
  • the general formula Li x Ni 1-m M m O n lithium-containing composite metal oxide represented by are preferred.
  • the lithium-containing composite metal oxide can be produced according to a known method. For example, it can be manufactured as follows. First, a composite metal hydroxide containing a metal other than lithium is prepared by a coprecipitation method using an alkali agent such as sodium hydroxide. Next, the composite metal hydroxide is subjected to a heat treatment to obtain a composite metal oxide. Subsequently, a lithium compound such as lithium hydroxide is added to the composite metal oxide and further heat-treated. Thereby, a lithium-containing composite metal oxide is obtained.
  • the olivine type lithium phosphate include LiXPO 4 (wherein X is at least one selected from the group consisting of Co, Ni, Mn and Fe).
  • the positive electrode active material one of the above-described active materials may be used alone, or two or more of them may be used in combination as necessary.
  • conductive agent those commonly used in the field of lithium secondary batteries can be used. Examples include graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black, and conductive fibers such as carbon fiber and metal fiber. It is done. One of these conductive agents may be used alone, or two or more may be used in combination as necessary.
  • binder those commonly used in the field of lithium secondary batteries can be used.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • polyethylene polypropylene
  • acrylic rubber acrylic rubber
  • polyvinyl acetate polyvinyl pyrrolidone
  • polyether polyether sulfone
  • hexafluoropolypropylene styrene butadiene rubber
  • modified acrylic examples thereof include rubber and carboxymethyl cellulose.
  • these binders one kind may be used alone, or two or more kinds may be used in combination as necessary.
  • the positive electrode active material layer 33 is formed as follows, for example. First, a positive electrode mixture slurry containing a positive electrode active material and having a conductive agent, a binder or the like dissolved or dispersed in an organic solvent is prepared as necessary. Next, the positive electrode mixture slurry is applied to the surface of the positive electrode current collector 31 and dried.
  • the organic solvent for example, dimethylformamide, dimethylacetamide, methylformamide, N-methyl-2-pyrrolidone (NMP), dimethylamine, acetone, cyclohexanone and the like can be used.
  • NMP N-methyl-2-pyrrolidone
  • dimethylamine acetone
  • cyclohexanone cyclohexanone
  • the thickness of the positive electrode active material layer 33 is appropriately selected according to various conditions such as the design performance and application of the lithium secondary battery 200.
  • the total thickness of the positive electrode active material layers 33 formed on both surfaces is preferably about 50 to 150 ⁇ m.
  • the porous insulating layer 15 contains an inorganic oxide as a main component, and has lithium ion permeability and insulating properties during normal use of the lithium secondary battery.
  • the porous insulating layer 15 may be composed of an inorganic oxide and a binder, or may be composed of an inorganic oxide and a heat resistant resin.
  • the inorganic oxide contained in the porous insulating layer 15 is not particularly limited as long as it can maintain insulation even when the battery generates heat and is chemically stable in the environment inside the battery. Moreover, if it has a high melting
  • the inorganic oxide include alumina (Al 2 O 3 ), silica (SiO 2 ), titania (TiO 2 ), zirconia (ZrO 2 ), magnesia (MgO), and yttria (Y 2 O 3 ). It can. Among these inorganic oxides, one kind may be used alone, or two or more kinds may be used in combination.
  • the median diameter of the inorganic oxide is preferably 0.05 ⁇ m or more and 10 ⁇ m or less.
  • binder used for the porous insulating layer 15 PVDF, acrylic rubber particles, PTFE or the like can be used.
  • PTFE or acrylic rubber particles it is preferably used in combination with carboxymethyl cellulose, polyethylene oxide, modified acrylonitrile rubber or the like as a thickener for paste or slurry.
  • One of these binders and thickeners may be used alone, or two or more thereof may be used in combination.
  • the heat-resistant resin constituting the porous insulating layer 15 is not particularly limited, but aramid, polyamideimide, cellulose and the like can be used.
  • a heat resistant resin may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, you may use combining a heat resistant resin and other resin.
  • the porosity of the porous insulating layer 15 is preferably 30% or more and 70% or less, more preferably 40% or more and 70% or less, in view of ion permeability, mechanical strength, and insulation. .
  • “Porosity” is the ratio of the volume of pores existing in the porous insulating layer 15 to the volume of the porous insulating layer 15. It is preferable that the porosity of the porous insulating layer 15 be equal to or higher than the porosity of the separator 13 described later. More preferably, it is higher than the porosity of the separator 13. Thereby, since more electrolyte solution can be hold
  • the porous insulating layer 15 containing an inorganic oxide and a binder has a relatively high mechanical strength, the durability is high.
  • the content ratio of the inorganic oxide in the porous insulating layer 15 is, for example, 80 to 95% by weight or more.
  • the porous insulating layer 15 may contain a heat resistant resin in a ratio exceeding 20% by weight, for example.
  • the porous insulating layer 15 containing a heat resistant resin and an inorganic oxide (for example, less than 80% by weight) can have a good balance between flexibility and durability.
  • the heat-resistant resin contributes to flexibility
  • the inorganic oxide having high mechanical strength contributes to durability.
  • the porous insulating layer 15 is formed on the surface of any one of the positive electrode active material layer 33 of the positive electrode 30, the negative electrode active material layer 23 of the negative electrode 20, and the resin porous film serving as the separator 13. It can be formed by casting the raw material of the layer. A plurality of porous insulating layers may be formed by casting the raw material of the porous insulating layer on any two or more of the above surfaces. For example, when a porous insulating layer is formed on the surfaces of the positive electrode active material layer 33 and the separator 13, two porous insulating layers 15a and 15b are provided between the positive electrode 30 and the negative electrode 20, as shown in FIG. it can.
  • the porous insulating layer 15 may be an independent sheet. In that case, it can be formed by casting the raw material on a porous sheet.
  • the independent sheet-like porous insulating layer 15 is disposed between the positive electrode 30 and the resin porous film (separator 13) or between the negative electrode 20 and the resin porous film (separator 13).
  • a plurality of porous insulating layers 15 may be disposed between the positive electrode 30 and the negative electrode 20.
  • the porous insulating layer 15 may be disposed between the positive electrode 30 and the negative electrode 20, but is preferably disposed between the separator 13 and the positive electrode 30. Thereby, the separator 13 exists between the porous insulating layer 15 and the negative electrode 20, and the porous insulating layer 15 is hardly affected by the expansion / contraction of the negative electrode active material. Can be prevented. Further, since the porous insulating layer 15 is disposed adjacent to the positive electrode active material layer 33, the stress applied to the positive electrode active material layer 33 can be more reliably reduced.
  • the porous insulating layer 15 is preferably disposed on the surface of the separator 13 on the positive electrode side or the negative electrode side, or on the surface of the positive electrode 30. In this case, it is preferable that the porous insulating layer 15 is integrally formed on the separator 13 or is integrally formed by coating the surface of the positive electrode active material layer 33. Thereby, a manufacturing process can be simplified rather than the case where the porous insulating layer 15 is formed independently.
  • the porous insulating layer 15 may be integrally formed on the surface of the negative electrode active material layer 23. However, if the porous insulating layer 15 is formed on the surface of the negative electrode active material layer 23, the mechanical properties may not be maintained due to expansion / contraction of the alloy-based active material. In addition, a part of the porous insulating layer 15 may enter the space in the negative electrode active material layer 23 (the space between the active material bodies), thereby impairing the original function.
  • an inorganic oxide and a binder are mixed with a liquid component to prepare a paste or slurry.
  • the binder is preferably 0.5 to 10 parts by weight per 100 parts by weight of the inorganic oxide, but is not particularly limited.
  • the inorganic oxide, the binder and the liquid component are mixed using, for example, a double kneader.
  • the obtained paste or slurry is applied onto at least one surface of the porous resin film that becomes the positive electrode 30, the negative electrode 20, and the separator 13.
  • the paste or slurry can be applied using, for example, a doctor blade or a die coat. Thereafter, the liquid component contained in the paste or slurry is removed by drying. In this way, the porous insulating layer 15 is obtained.
  • the porous insulating layer 15 may be formed using an inorganic oxide and a heat resistant resin.
  • a resin solution in which a heat resistant resin is dissolved in a solvent is prepared.
  • the solvent for dissolving the heat-resistant resin is not particularly limited, but is preferably a polar solvent such as N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP).
  • NMP N-methyl-2-pyrrolidone
  • 500 g or less (preferably 33 g to 300 g) of inorganic oxide may be dispersed per 100 g of heat resistant resin.
  • the resin solution is applied on at least one surface of the positive electrode 30, the negative electrode 20, and the porous resin film. Thereafter, the solvent is removed by drying to obtain a porous insulating layer 15 containing a heat resistant resin.
  • the negative electrode 20 includes a negative electrode current collector 21 and a negative electrode active material layer 23.
  • the negative electrode current collector 21 those commonly used in the field of lithium secondary batteries can be used.
  • a porous or non-porous conductive substrate made of a metal material such as stainless steel, titanium, nickel, copper, or a conductive resin can be used.
  • the porous conductive substrate include a mesh body, a net body, a punching sheet, a lath body, a porous body, a foam, a fiber group molded body (nonwoven fabric, etc.), and the like.
  • the non-porous conductive substrate include a foil, a sheet, and a film.
  • the thickness of the porous or non-porous conductive substrate is not particularly limited, but is usually 1 to 500 ⁇ m, preferably 1 to 50 ⁇ m, more preferably 10 to 40 ⁇ m, and particularly preferably 10 to 30 ⁇ m. Further, as will be described later, the surface of the negative electrode current collector 21 is provided with a plurality of convex portions.
  • the negative electrode active material layer 23 contains an alloy-based active material and is formed in a thin film on one or both surfaces of the negative electrode current collector 21. Moreover, the negative electrode active material layer 23 may contain a well-known negative electrode active material, an additive, etc. in the range which does not impair the characteristic with an alloy type active material. Furthermore, the thickness of the negative electrode active material layer 23 (thickness when the negative electrode active material layer 23 is formed) is preferably 3 to 50 ⁇ m. The negative electrode active material layer 23 is preferably amorphous or low crystalline.
  • the alloy-based active material is a negative electrode active material that occludes lithium by alloying with lithium during charging and releases lithium during discharging. It does not restrict
  • a silicon containing compound, a tin containing compound, etc. are mentioned.
  • the silicon-containing compound include silicon, silicon oxide, silicon nitride, silicon-containing alloy, silicon compound and its solid solution.
  • the silicon oxide include silicon oxide represented by the composition formula: SiO ⁇ (0 ⁇ ⁇ 2).
  • silicon carbide include silicon carbide represented by the composition formula: SiC ⁇ (0 ⁇ ⁇ 1).
  • Examples of the silicon nitride include silicon nitride represented by the composition formula: SiN ⁇ (0 ⁇ ⁇ 4/3).
  • Examples of the silicon-containing alloy include an alloy containing silicon and one or more elements selected from the group consisting of Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, and Ti. . Further, a part of silicon is selected from the group consisting of B, Mg, Ni, Ti, Mo, Co, Ca, Cr, Cu, Fe, Mn, Nb, Ta, V, W, Zn, C, N, and Sn. It may be substituted with one or more elements. Among these, it is particularly preferable to use SiO ⁇ (0 ⁇ ⁇ 2) which is excellent in reversibility of charge / discharge.
  • tin-containing compound examples include tin, tin oxide, tin nitride, tin-containing alloy, tin compound and its solid solution, and the like.
  • tin-containing compounds include tin, tin oxides such as SnO ⁇ (0 ⁇ ⁇ 2), SnO 2 , Ni—Sn alloys, Mg—Sn alloys, Fe—Sn alloys, Cu—Sn alloys, and Ti—Sn.
  • Tin-containing alloys such as alloys, tin compounds such as SnSiO 3 , Ni 2 Sn 4 and Mg 2 Sn can be preferably used.
  • tin and tin oxides such as SnO ⁇ (0 ⁇ ⁇ 2) and SnO 2 are particularly preferable.
  • the negative electrode active material layer 23 is an aggregate of a plurality of columnar bodies (active material bodies) containing an alloy-based active material. As described above with reference to FIG. 1, these active material bodies contain an alloy-based active material and are arranged on the surface of the negative electrode current collector 21 with a space therebetween. Each active material body extends from the surface of the negative electrode current collector 21 in a direction away from the surface of the negative electrode current collector 21. Preferably, the plurality of active material bodies are formed to extend in the same direction.
  • Such a negative electrode active material layer 23 can be manufactured by providing a plurality of convex portions on the surface of the negative electrode current collector 21 and forming an active material body on each of the convex portions.
  • FIG. 8 is an enlarged cross-sectional view illustrating a part of the negative electrode 20.
  • FIG. 8 shows only one active material body.
  • FIG. 9 is a schematic perspective view of the negative electrode current collector 21.
  • the negative electrode current collector 21 has a plurality of convex portions 22 on the surface (surface on which the negative electrode active material layer is to be formed) 21a.
  • the convex portion 22 may be similarly provided on the surface opposite to the surface 21a.
  • the convex portion 22 is a protrusion that extends from the surface 21 a of the negative electrode current collector 21 in a direction away from the negative electrode current collector 21.
  • the convex portions 22 may be randomly arranged, or may be regularly arranged as illustrated. It is preferable that the convex portions 22 are regularly arranged because the size of the space formed between the active material bodies 24 can be easily controlled by the pitch and size of the convex portions 22.
  • the height (average height) h of the convex portion 22 is not particularly limited, but is preferably 3 ⁇ m or more. If it is 3 micrometers or more, when forming the active material body 24 by the oblique vapor deposition mentioned later, the active material body 24 can be selectively arrange
  • the height h of the convex portion 22 is preferably 10 ⁇ m or less. If the convex part 22 is 10 micrometers or less, since the volume ratio of the electrical power collector 11 which occupies for an electrode can be restrained small, it becomes possible to obtain a high energy density.
  • the height (average height) h of the convex portion 22 is perpendicular to the surface 21 a of the negative electrode current collector 21 and includes a vertex of the convex portion 22.
  • a vertex of the convex portion 22 refers to the highest point with respect to the surface 21 a of the negative electrode current collector 21.
  • the “surface 21a” refers to the surface of the surface of the negative electrode current collector 21 where the convex portions 22 are not formed.
  • the average height of the convex portions 22 is obtained by, for example, observing a cross section of the negative electrode 20 perpendicular to the surface of the negative electrode current collector 21 with a scanning electron microscope (SEM), and measuring the height of the 100 convex portions 22. , By calculating an average value thereof.
  • SEM scanning electron microscope
  • the cross-sectional diameter r of the convex portion 22 is not particularly limited, but is preferably 1 ⁇ m or more, for example. Thereby, the contact area of the convex part 22 and the active material body 24 is fully securable. On the other hand, the cross-sectional diameter r is preferably 50 ⁇ m or less. When the cross-sectional diameter r is larger than 50 ⁇ m, there may be a case where sufficient voids cannot be formed between the active material bodies 24.
  • the cross-sectional diameter r of the convex portion 22 indicates the maximum width of the convex portion 22 in a direction parallel to the surface 21 a in a cross section that is perpendicular to the surface of the negative electrode current collector 21 and includes the apex of the convex portion 22.
  • the cross-sectional diameter r of the convex portion 22 can also be obtained by measuring the width of 100 convex portions 22 and calculating the average value of these measured values.
  • the plurality of convex portions 22 may not all have the same height h or the same cross-sectional diameter r.
  • the shape of the convex part 22 seen from the normal line direction of the negative electrode 20 is circular.
  • the shape of the convex part 22 here is a convex part as viewed from above in the vertical direction when the current collector 21 is placed so that the surface opposite to the surface 21a of the negative electrode current collector 21 coincides with the horizontal plane. 22 shapes.
  • the shape of the convex part 22 is not limited to a circle, For example, a polygon, an ellipse, a parallelogram, a trapezoid, a rhombus, etc. may be sufficient.
  • the convex portion 22 preferably has a substantially planar apex p at the tip portion in the extending direction.
  • the convex portion 22 has a circular top portion p.
  • the bondability of the convex part 22 and the active material body 24 will improve.
  • the planar apex p is substantially parallel to the surface 21a, since the bonding strength between the convex portion 22 and the active material body 24 can be further increased.
  • the number of protrusions 22 per unit area, the interval between the protrusions 22, and the like are not particularly limited, and the size (height, cross-sectional diameter, etc.) of the protrusions 22 and the active material body 24 provided on the surface of the protrusions 22. It is appropriately selected according to the size of the.
  • the number of convex portions 22 per unit area is, for example, about 10,000 to 10 million pieces / cm 2 .
  • the inter-axis distance d of the adjacent convex part 22 is about 2 micrometers or more and about 100 micrometers, for example.
  • the convex portions 22 are preferably arranged regularly at a predetermined arrangement pitch, and may be arranged in a pattern such as a houndstooth pattern or a grid pattern.
  • the arrangement pitch of the protrusions 22 (the distance between the centers of the adjacent protrusions 22) is, for example, not less than 10 ⁇ m and not more than 100 ⁇ m.
  • the “center of the convex portion 22” refers to the center point of the maximum width on the upper surface (top portion) of the convex portion 22. If the arrangement pitch is 10 ⁇ m or more, a space for expanding the active material members 24 can be more reliably secured between the adjacent active material members 24. On the other hand, when the arrangement pitch is 100 ⁇ m or less, a high capacity can be secured without increasing the height of the active material body 24.
  • the ratio of the interval between the protrusions 22 to the arrangement pitch of the protrusions 22 is 1/3 or more and 2/3 or less. If the spacing ratio is 1/3 or more, when the active material bodies 24 are formed on the respective convex portions 22, the widths of the gaps in the active material bodies 24 in the respective arrangement directions of the convex portions 22 are more reliably ensured. It can be secured. On the other hand, when the proportion of the spacing is larger than 2/3, the active material is also present in the spacing (also referred to as “concave portion” or “groove”) between the convex portions 22 when forming the active material body by oblique deposition. As a result, the expansion stress applied to the negative electrode current collector 21 may increase.
  • the interval between the adjacent convex portions 22 is the width of the convex portion 22. It is preferable that it is 30% or more. As a result, a sufficient gap can be secured between the active material members 24 to significantly relieve the expansion stress. On the other hand, if the distance between the adjacent convex portions 22 is too large, the thickness of the negative electrode active material layer 23 increases in order to ensure capacity. Therefore, in the cross section of the negative electrode 20, the interval between the protrusions 22 is preferably 250% or less of the width of the protrusions 22.
  • a protrusion (not shown) may be formed on the surface of the convex portion 22 by plating or the like. Thereby, since the joining property of the convex part 22 and the active material body 24 can be improved effectively, peeling from the convex part 22 of the active material body 24, peeling propagation, etc. can be prevented more reliably.
  • the protrusion is provided so as to protrude from the surface of the protrusion 22 to the outside of the protrusion 22.
  • the width and height of the protrusions are smaller than the width and height of the protrusions 22, and a plurality of protrusions may be formed on the surface of each protrusion 22.
  • protrusions may be formed on the side surfaces of the protrusions 22 so as to extend in the circumferential direction and / or the growth direction of the protrusions 22.
  • the convex part 22 has a planar top part, one or more protrusions smaller than the convex part 22 may be formed in each top part. The protrusion formed on the top may extend in one direction.
  • the upper surface of the convex portion 22 may be flat, but preferably has irregularities.
  • the unevenness can be formed, for example, by forming a protrusion on the upper surface of the convex portion 22 as described above.
  • the surface roughness Ra of the upper surface of the convex portion 22 is preferably 0.3 ⁇ m or more and 5.0 ⁇ m or less. As a result, a sufficient adhesion force between the convex portion 22 and the active material body 24 can be ensured, so that the active material body 24 can be prevented from peeling off.
  • “Surface roughness Ra” here refers to “arithmetic average roughness Ra” defined in Japanese Industrial Standards (JISB0601-1994), and can be measured using, for example, a surface roughness meter.
  • the boundary between the convex portion 22 and portions other than the convex portion (“groove”, “concave portion”) is not clear. May be.
  • a portion having an average height or more of the entire surface having the concavo-convex pattern is referred to as a “projection 22”, and a portion less than the average height is referred to as a “groove” or “concave”.
  • a plane including the bottom of the recess is referred to as “surface 21a”.
  • the negative electrode current collector 21 in the present embodiment can be produced by forming irregularities on a current collector material sheet such as a metal foil or a metal sheet.
  • a current collector material sheet such as a metal foil or a metal sheet.
  • the method for forming the unevenness include a method of transferring the surface of a roller having a plurality of recesses formed on the surface (hereinafter referred to as “roller processing method”), a photoresist method, and the like.
  • a current collector raw material sheet is mechanically pressed using a roller having a recess formed on the surface (hereinafter referred to as a “projection forming roller”).
  • the some convex part 22 can be formed in the at least one surface of the raw material sheet
  • the material sheet for the current collector a sheet containing the material as described above as the material of the negative electrode current collector 21 can be used.
  • the negative electrode active material layer 23 includes a plurality of columnar active material bodies 24 extending from the surface of the convex portion 22 toward the outside of the negative electrode current collector 21.
  • Each active material body 24 may extend in the normal direction D of the surface 21 a of the negative electrode current collector 21. Alternatively, it may extend in a direction inclined with respect to the normal direction D.
  • Each active material body 24 may have a structure in which a plurality of columnar lumps having different growth directions are stacked.
  • Each active material member 24 preferably has a gap between adjacent active material members 24 at least before charging. This gap can relieve stress due to expansion and contraction during charging / discharging, so that the active material body 24 is difficult to peel off from the convex portion 22. As a result, deformation of the negative electrode current collector 21 and the negative electrode 20 can be suppressed.
  • the width of the gap between the active material bodies 24 can be adjusted by the arrangement pitch or size of the protrusions 22. Further, these active material bodies 24 may be arranged immediately after the formation of the negative electrode active material layer 23 or at intervals during discharging, but adjacent active material bodies 24 may come into contact with each other during charging.
  • the active material body 24 may have a structure in which n (n ⁇ 2) layers (columnar blocks) are stacked. A larger number n is more preferable. For example, as shown in FIG. 10, it may be a columnar product in which eight columnar chunks 24a, 24b, 24c, 24d, 24e, 24f, 24g, and 24h are laminated.
  • the negative electrode active material layer 23 including such an active material body 24 is formed as follows. First, the columnar chunk 24a is formed so as to cover the top of the convex portion 22 and a part of the side surface following the top. Next, the columnar chunk 24b is formed so as to cover the remaining side surface of the convex portion 22 and a part of the top surface of the columnar chunk 24a. That is, in the cross-sectional view shown in FIG. 10, the columnar chunk 24a is formed at one end including the top of the convex portion 22, the columnar chunk 24b partially overlaps the columnar chunk 24a, but the remaining portion is the convex portion. 22 is formed at the other end.
  • the columnar chunk 24c is formed so as to cover the rest of the top surface of the columnar chunk 24a and a part of the top surface of the columnar chunk 24b. That is, the columnar chunk 24c is formed so as to mainly contact the columnar chunk 24a. Further, the columnar chunk 24d is formed mainly in contact with the columnar chunk 24b. Similarly, the active material body 24 is formed by alternately stacking the columnar chunks 24e, 24f, 24g, and 24h.
  • FIG. 11 is a cross-sectional view illustrating an electron beam evaporation apparatus 50 used for forming the negative electrode active material layer 23.
  • each member inside the vapor deposition apparatus 50 is also indicated by a solid line.
  • the vapor deposition apparatus 50 includes a chamber 51, a first pipe 52, a fixing base 53, a nozzle 54, a target (evaporation source) 55, an electron beam generator not shown, a power source 56, and a second pipe not shown.
  • the chamber 51 is a pressure-resistant container-like member having an internal space, and a first pipe 52, a fixing base 53, a nozzle 54, and a target 55 are accommodated therein.
  • the first pipe 52 supplies the source gas to the nozzle 54.
  • One end of the first pipe 52 is connected to the nozzle 54.
  • the other end of the first pipe 52 extends to the outside of the chamber 51 and is connected to a source gas cylinder or a source gas manufacturing apparatus (not shown) via a mass flow controller (not shown).
  • As source gas, oxygen, nitrogen, etc. can be used, for example.
  • the fixing base 53 is a plate-like member, and is supported so as to be angularly displaced or rotatable with respect to the horizontal plane 60.
  • the negative electrode current collector 21 is fixed to one surface of the fixing base 53.
  • the position of the fixing base 53 is switched between a first position indicated by a solid line and a second position indicated by a one-dot broken line, whereby the deposition angle can be switched.
  • the first position is that the surface of the fixing base 53 on the side where the negative electrode current collector 21 is fixed is opposed to the nozzle 54 below in the vertical direction, and the angle between the fixing base 53 and the horizontal plane 60 is ⁇ °.
  • the second position is such that the surface of the fixing base 53 on the side where the negative electrode current collector 21 is fixed is opposed to the nozzle 54 below in the vertical direction, and the angle formed by the fixing base 53 and the horizontal plane 60 is (180 ⁇ ). It is a position that becomes °.
  • the angle ⁇ ° is appropriately selected according to the dimensions of the active material body 24 to be formed.
  • the nozzle 54 is provided between the fixed base 53 and the target 55 in the vertical direction.
  • the nozzle 54 mixes the vapor of evaporation material such as an alloy-based active material that evaporates from the target 55 and rises upward in the vertical direction, and the raw material gas supplied from the first pipe 52, and the surface of the fixed base 53. To the surface of the negative electrode current collector 21 fixed to the surface.
  • the target 55 accommodates an alloy-based negative electrode active material or its raw material.
  • the electron beam generator irradiates and heats an alloy-based active material accommodated in the target 55 or its raw material with an electron beam to generate these vapors.
  • the power source 56 is provided outside the chamber 51 and is electrically connected to the electron beam generator, and applies a voltage for generating an electron beam to the electron beam generator.
  • the second pipe introduces a gas that becomes the atmospheric gas in the chamber 51.
  • the negative electrode current collector 21 is fixed to the fixing base 53, and the fixing base 53 is set to the first position.
  • Oxygen gas is introduced into the chamber 51 using the second pipe 52 and the nozzle 54.
  • the alloy-based negative electrode active material of the target 55 or its raw material is irradiated with an electron beam and heated to generate its vapor.
  • SiO ⁇ (0 ⁇ ⁇ 2) is used as the alloy-based active material.
  • the generated silicon vapor rises upward in the vertical direction, and is mixed with oxygen supplied from the nozzle 54 when passing through the nozzle 54. Thereafter, the silicon vapor and oxygen are further raised and supplied to the surface of the negative electrode current collector 21 fixed to the fixed base 53.
  • silicon vapor and oxygen gas react to grow silicon oxide.
  • silicon atoms fly toward the surface of the negative electrode current collector 21 from a direction inclined by an angle ⁇ 1 (deposition angle) with respect to the normal direction of the negative electrode current collector 21.
  • the oxygen is supplied from the nozzle 54 near the surface of 21.
  • silicon oxide is deposited on the surface of the negative electrode current collector 21.
  • the vapor deposition angle ⁇ 1 is equal to the angle ⁇ formed by the fixed base 53 and the horizontal plane 60.
  • the direction in which oxygen is supplied is not particularly limited. Here, oxygen is supplied to the surface of the negative electrode current collector 21 from the back of the sheet of FIG.
  • the material of the evaporation source silicon
  • the material of the evaporation source silicon
  • the silicon oxide grows in a columnar shape selectively only on the top.
  • silicon atoms do not enter the portion of the surface of the negative electrode current collector 21 that is shadowed by the silicon oxide that grows in a columnar shape, and silicon oxide is difficult to deposit (shadowing effect). In this way, the columnar mass 24a of the active material body shown in FIG. 10 is formed.
  • the fixed base 53 is rotated and set to the second position, and silicon oxide is grown in the same manner as described above.
  • silicon atoms and oxygen gas are introduced to the surface of the negative electrode current collector 21 from a direction inclined to the opposite side of the vapor deposition direction when forming the columnar mass 24 a with respect to the normal direction of the negative electrode current collector 21.
  • an active material body composed of a plurality of columnar chunks 24a to 24h The negative electrode active material layer 23 containing 24 can be formed.
  • the growth direction of the columnar mass 24 a is inclined by the angle ⁇ 1 with respect to the normal direction D of the negative electrode current collector 21.
  • the inclination angle ⁇ 1 is determined by the deposition angle (silicon incident angle) ⁇ 1 .
  • the inclination angle calculated from the above relational expression is lowered by controlling the pressure in the vacuum chamber by changing the oxygen introduction amount. Therefore, the inclination angle ⁇ 1 can be controlled by changing the deposition angle ⁇ 1 and the vacuum chamber internal pressure.
  • the growth direction of the columnar chunk 24 b is inclined by an angle ⁇ 2 in the direction opposite to the growth direction of the columnar chunk 24 a with respect to the normal direction D of the negative electrode current collector 21.
  • the growth directions of the plurality of columnar chunks 24a to 24h are changed. Are alternately inclined in the opposite direction with respect to the normal direction D of the negative electrode current collector 21.
  • the active material body 24 formed by the above method has a chemical composition of SiO x .
  • the average value of the molar ratio x of the oxygen amount to the silicon amount is greater than 0 and less than 2.
  • the active material body 24 may be formed so that an oxygen concentration gradient is formed in the thickness direction of the active material body 24.
  • the oxygen content may be increased in a portion close to the negative electrode current collector 21, and the oxygen content may be reduced as the distance from the negative electrode current collector 21 increases.
  • the higher the oxygen content, that is, the closer x is to 2 the smaller the volume expansion coefficient of the active material due to occlusion of lithium.
  • the volume capacity density (mAh / cm 3 ) can be increased as the oxygen content is lower, that is, as x is closer to zero, but the volume expansion coefficient is increased. Therefore, in the active material body 24 having the oxygen concentration gradient as described above, the expansion / shrinkage of the active material can be suppressed in the portion close to the negative electrode current collector 21, so that the bonding between the convex portion 22 and the active material body 24 is performed. The sex can be further improved. Moreover, in the part away from the negative electrode collector 21, since the oxygen content is small, the volume capacity density is high.
  • the formation method of the active material body 24 is not limited to the method mentioned above.
  • the raw material gas may not be supplied from the nozzle 54 and the active material body 24 mainly composed of silicon or tin may be formed.
  • vapor deposition may be performed with a constant deposition angle without switching. Thereby, the active material body 24 grown along one direction is obtained. Further, during the vapor deposition, the vapor deposition angle may be changed by rotating the fixed base 53 along the rotation axis to change the installation direction of the negative electrode current collector 21.
  • the number of times of vapor deposition is not particularly limited.
  • the vapor deposition angle is alternately switched between 60 ° and ⁇ 60 °, for example, and vapor deposition is performed up to the n-th stage (n ⁇ 2), the active material body 24 having n portions can be formed.
  • the negative electrode active material layer is formed using oblique vapor deposition, but lift-off as described in Patent Document 3 can be used instead.
  • a negative electrode active material layer having a columnar structure may be formed by depositing an active material film and then patterning.
  • ⁇ Separator 13> As the separator 13, a sheet or film having characteristics such as predetermined ion permeability, mechanical strength, and insulating properties are used. Specific examples of the separator 13 include porous sheets or films such as a microporous film, a woven fabric, and a non-woven fabric. The microporous film may be either a single layer film or a multilayer film. Although various resin materials can be used as the material of the separator 13, it is preferable to use polyolefins such as polyethylene and polypropylene in consideration of durability, shutdown function, battery safety, and the like.
  • the thickness of the separator 13 is generally 10 to 300 ⁇ m, preferably 10 to 40 ⁇ m, more preferably 10 to 30 ⁇ m, and further preferably 10 to 25 ⁇ m.
  • the porosity of the separator 13 is preferably 30 to 70%, more preferably 35 to 60%.
  • a nonaqueous electrolyte having lithium ion conductivity is suitably used as the electrolytic solution (nonaqueous electrolyte) used in the present embodiment.
  • the non-aqueous electrolyte may be, for example, a liquid non-aqueous electrolyte, a gel-like non-aqueous electrolyte, a solid electrolyte (for example, a polymer solid electrolyte), or the like.
  • the liquid non-aqueous electrolyte contains a solute (supporting salt) and a non-aqueous solvent, and further contains various additives as necessary. Solutes usually dissolve in non-aqueous solvents.
  • solute those commonly used in this field can be used.
  • LiClO 4 , LiBF 4 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiBr, LiI, LiBCl 4 , borate salts, imide salts and the like can be mentioned.
  • borates include lithium bis (1,2-benzenediolate (2-)-O, O ′) borate, bis (2,3-naphthalenedioleate (2-)-O, O ′) boric acid.
  • imide salts include lithium bistrifluoromethanesulfonate imide ((CF 3 SO 2 ) 2 NLi), lithium trifluoromethanesulfonate nonafluorobutanesulfonate ((CF 3 SO 2 ) (C 4 F 9 SO 2 ) NLi) ), Lithium bispentafluoroethanesulfonate imide ((C 2 F 5 SO 2 ) 2 NLi), and the like.
  • One of the above solutes may be used alone, or two or more may be used in combination as necessary.
  • the amount of the solute dissolved in the non-aqueous solvent is preferably in the range of 0.5 to 2.0 mol / L.
  • non-aqueous solvent those commonly used in this field can be used.
  • cyclic carbonate ester, chain carbonate ester, cyclic carboxylic acid ester and the like can be mentioned.
  • the cyclic carbonate include propylene carbonate (PC) and ethylene carbonate (EC).
  • the chain carbonate include diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), and the like.
  • examples of the cyclic carboxylic acid ester include ⁇ -butyrolactone (GBL) and ⁇ -valerolactone (GVL).
  • GBL ⁇ -butyrolactone
  • VTL ⁇ -valerolactone
  • One of the non-aqueous solvents may be used alone, or two or more may be used in combination as necessary.
  • the gel-like non-aqueous electrolyte includes a liquid non-aqueous electrolyte and a polymer material that holds the liquid non-aqueous electrolyte.
  • the polymer material used here is capable of gelling a liquid material.
  • the polymer material those commonly used in this field can be used. Examples thereof include polyvinylidene fluoride, polyacrylonitrile, polyethylene oxide, polyvinyl chloride, polyacrylate, and polyvinylidene fluoride.
  • the solid electrolyte includes, for example, a solute (supporting salt) and a polymer material. Solutes similar to those exemplified above can be used.
  • the polymer material include polyethylene oxide (PEO), polypropylene oxide (PPO), a copolymer of ethylene oxide and propylene oxide, and the like.
  • ⁇ Positive electrode and negative electrode lead, outer case> One end of the positive electrode lead 18 is connected to the positive electrode current collector 31, and the other end is led out from the opening 17 a of the outer case 17 to the outside of the lithium secondary battery 1.
  • One end of the negative electrode lead 19 is connected to the negative electrode current collector 12 a, and the other end is led out of the lithium secondary battery 1 from the opening 17 b of the outer case 17.
  • the openings 17 a and 17 b of the outer case 17 are sealed with a gasket 16.
  • the gasket 16 for example, various resin materials can be used.
  • the outer case 17 any one commonly used in the technical field of lithium secondary batteries can be used.
  • the openings 17a and 17b of the outer case 17 may be directly sealed by welding or the like.
  • the lithium secondary battery 200 can be manufactured, for example, as follows. Here, a case where the porous insulating layer 15 is integrally formed with the positive electrode 30 will be described as an example.
  • the negative electrode 20, the positive electrode 30, and the separator 13 are prepared.
  • the porous insulating layer 15 is integrally formed on the surface of the positive electrode active material layer 33 in the positive electrode 30.
  • one end of the positive electrode lead 18 is connected to a portion of the surface of the positive electrode current collector 31 of the positive electrode 30 where the positive electrode active material layer 33 is not formed.
  • one end of the negative electrode lead 19 is connected to a portion of the surface of the negative electrode current collector 21 of the negative electrode 20 where the negative electrode active material layer 23 is not formed.
  • the positive electrode 30 and the negative electrode 20 are laminated via the separator 13 to produce an electrode group.
  • the positive electrode 30, the negative electrode 20, and the separator 13 are disposed so that the positive electrode active material layer 33 and the negative electrode active material layer 23 face each other.
  • the obtained electrode group is inserted into the outer case 17 together with the electrolyte, and the other ends of the positive electrode lead 18 and the negative electrode lead 19 are led out of the outer case 17.
  • the openings 17 a and 17 b are welded through the gasket 16 while the inside of the outer case 17 is vacuum-depressurized. In this way, the lithium secondary battery 200 is obtained.
  • the structure and manufacturing method of the lithium secondary battery of this embodiment are not limited to the structure and method mentioned above.
  • FIG. 7 shows a lithium secondary battery having a stacked electrode group
  • the lithium secondary battery of this embodiment may be a cylindrical battery or a square battery having a wound electrode group. Good.
  • Example A Examples 1 to 5 and Comparative Examples 1 and 2
  • Examples 1 to 5 and Comparative Examples 1 and 2 Lithium secondary batteries having porous insulating layers (Examples 1 to 5) and lithium secondary batteries having no porous insulating layer (Comparative Examples 1 and 2) were produced. Characteristics were evaluated. Hereinafter, the production methods, evaluation methods, and evaluation results of the lithium secondary batteries of Examples and Comparative Examples will be described.
  • aqueous solution containing nickel sulfate at a concentration of 0.82 mol / liter, an aqueous solution containing cobalt sulfate at a concentration of 0.15 mol / liter, and an aqueous solution containing aluminum sulfate at a concentration of 0.03 mol / liter were prepared.
  • a mixed solution of these aqueous solutions was continuously supplied to the reaction vessel.
  • a precursor of the active material was synthesized while sodium hydroxide was dropped into the reaction tank so that the pH of the aqueous solution in the reaction tank was maintained between 10 and 13.
  • the obtained precursor was sufficiently washed with water and dried. In this way, a hydroxide made of Ni 0.82 Co 0.15 Al 0.03 (OH) 2 was obtained as a precursor.
  • the obtained precursor and lithium carbonate were mixed so that the molar ratio of lithium, cobalt, nickel and aluminum (Ni: Co: Ni: Al) was 1: 0.82: 0.15: 0.03 did.
  • the mixture was calcined in an oxygen atmosphere at a temperature of 500 ° C. for 7 hours and pulverized.
  • the pulverized fired product was fired again at a temperature of 800 ° C. for 15 hours.
  • the fired product was pulverized and classified to obtain a positive electrode active material having a composition represented by LiNi 0.82 Co 0.15 Al 0.03 O 2 .
  • a positive electrode was produced by the following method.
  • the positive electrode active material powder 100 g of the positive electrode active material powder is sufficiently mixed with 2 g of acetylene black (conductive agent), 2 g of artificial graphite (conductive agent), 3 g of polyvinylidene fluoride powder (binder) and 50 ml of organic solvent (NMP).
  • a paste was prepared. This positive electrode mixture paste was applied to one side of an aluminum foil (positive electrode current collector) having a thickness of 15 ⁇ m. The mixture paste was dried to obtain a positive electrode active material layer.
  • the thickness of the positive electrode that is, the total thickness of the positive electrode current collector and the positive electrode active material layer was set to 128 ⁇ m.
  • Example 2 Formation of porous insulating layer
  • the porous insulating layer was formed on the surface of the positive electrode active material layer.
  • alumina powder manufactured by Sumitomo Chemical Co., Ltd., AKP3000
  • NMP solution BM-720H (trade name) manufactured by Nippon Zeon Co., Ltd.
  • BM-720H trade name
  • a suitable amount of NMP was stirred with a double-arm kneader.
  • a slurry for forming a porous insulating layer was prepared.
  • the obtained slurry was applied over the entire surface of the positive electrode active material layer on the surface of the positive electrode active material layer.
  • the applied slurry was dried at 100 ° C. for 10 hours under vacuum and reduced pressure to form a porous heat-resistant layer.
  • the thickness of the porous heat-resistant layer was 1 ⁇ m. Further, the porosity of the porous heat-resistant layer was 49%.
  • Example 1 Production of Negative Electrode
  • a negative electrode current collector having irregularities on the surface was produced by a roller processing method.
  • chromium oxide was sprayed onto the surface of a cylindrical iron roller (diameter: 50 mm) to form a ceramic layer having a thickness of 100 ⁇ m.
  • a plurality of recesses having a depth of 8 ⁇ m were formed on the surface of the ceramic layer by laser processing.
  • Each recess was circular with a diameter of 12 ⁇ m when viewed from above the ceramic layer.
  • the central portion was substantially planar, and the peripheral edge of the bottom had a rounded shape.
  • the arrangement of these recesses was a close-packed arrangement in which the distance between the axes of adjacent recesses was 20 ⁇ m. In this way, a convex forming roller was obtained.
  • an alloy copper foil (trade name: HCL-02Z, thickness: 26 ⁇ m, manufactured by Hitachi Cable Ltd.) containing zirconia at a ratio of 0.03% by weight with respect to the total amount was placed at 600 ° C. in an argon gas atmosphere. Heating was performed for 30 minutes at a temperature, and annealing was performed.
  • This alloy copper foil was passed at a pressure of 2 t / cm through a pressure contact portion where two convex forming rollers were pressure contacted. Thereby, both surfaces of alloy copper foil were pressure-molded, and the negative electrode collector which has a some convex part on both surfaces was obtained.
  • a cross section perpendicular to the surface of the negative electrode current collector was observed with a scanning electron microscope, a plurality of convex portions having an average height of about 8 ⁇ m were formed on both surfaces of the negative electrode current collector.
  • a negative electrode active material layer was formed on the surface of the obtained negative electrode current collector by oblique vapor deposition using an electron beam vapor deposition apparatus 50 shown in FIG.
  • the conditions for vapor deposition are as follows.
  • a negative electrode current collector having a size of 30 mm ⁇ 30 mm was fixed to a fixed base.
  • Negative electrode active material raw material silicon, purity 99.9999%, manufactured by High Purity Chemical Laboratory Co., Ltd.
  • Oxygen released from nozzle purity 99.7%, manufactured by Nippon Oxygen Co., Ltd.
  • Emission 500mA
  • Deposition time 3 minutes ⁇ 40 times This formed a negative electrode active material layer containing a plurality of active material bodies on one surface of the negative electrode current collector.
  • Each of the active material bodies had a structure in which 40 columnar lumps were laminated, and was arranged on the corresponding convex part of the negative electrode current collector. Moreover, it grew from the top part of the convex part and the side surface near the top part in the direction in which the convex part extends.
  • the thickness of the negative electrode active material layer was determined.
  • a cross section perpendicular to the negative electrode current collector in the obtained negative electrode is observed with a scanning electron microscope, and for 10 active material bodies formed on the surface of the convex portion, from the vertex of the convex portion to the vertex of the active material body. The length of each was measured. The average of these was calculated as “the thickness of the negative electrode active material layer”.
  • the thickness of each negative electrode active material layer was 15 ⁇ m.
  • the composition of the compound constituting the negative electrode active material layer was all SiO 0.4 .
  • lithium metal was deposited on the surface of these negative electrode active material layers. This is because lithium metal is deposited to supplement lithium corresponding to the irreversible capacity stored in the negative electrode active material layer during the first charge / discharge.
  • the vapor deposition of lithium metal was performed using a resistance heating vapor deposition apparatus (manufactured by ULVAC, Inc.) in an argon atmosphere.
  • a resistance heating vapor deposition apparatus manufactured by ULVAC, Inc.
  • lithium metal was loaded into a tantalum boat in a resistance heating vapor deposition apparatus.
  • the negative electrode was fixed so that one of the negative electrode active material layers formed on both surfaces of the negative electrode current collector faced the tantalum boat.
  • a 50 A current was passed through the tantalum boat in an argon atmosphere to deposit lithium metal.
  • the deposition time was 10 minutes.
  • lithium metal was deposited on the other negative electrode active material layer in the same manner.
  • the positive electrode having a porous insulating layer formed on the surface was cut out so that the planar shape of the positive electrode active material layer was a square of 20 mm ⁇ 20 mm.
  • the positive electrode lead was welded to the portion of the surface of the positive electrode current collector where the positive electrode active material layer was not formed to obtain a positive electrode plate.
  • the negative electrode after the lithium metal was deposited was cut out so that the planar shape of the negative electrode active material layer was a square of 21 mm ⁇ 21 mm and a tab portion of 5 mm ⁇ 5 mm was formed at one corner where two sides intersected.
  • the negative electrode active material layer located in the tab portion was peeled off, and the negative electrode lead was welded to the surface of the current collector exposed by peeling of the negative electrode active material layer. In this way, a negative electrode plate was obtained.
  • the positive electrode plate, the negative electrode plate, and the separator were arranged so that the positive electrode active material layer and the negative electrode active material layer faced each other with the separator interposed therebetween, thereby preparing an electrode group.
  • the negative electrode plate was set as the center, and the separator and the positive electrode plate were laminated in this order on both surfaces.
  • a polyethylene microporous membrane (trade name: Hypore, thickness: 16 ⁇ m, porosity: 40%, manufactured by Asahi Kasei Co., Ltd.) was used as the separator.
  • the structure of the electrode group obtained in this example is shown in FIG. In FIG. 13, the same reference numerals are given to the same components as those in FIG.
  • the obtained electrode group was inserted into an outer case made of an aluminum laminate together with 0.5 g of an electrolyte.
  • LiPF 6 was dissolved at a concentration of 1.4 mol / L in a solvent in which ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed at a volume ratio of 2: 3: 5 as an electrolyte.
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DEC diethyl carbonate
  • a non-aqueous electrolyte was used.
  • the ionic conductivity was 6.5 mS / cm, and the viscosity was 6.2 cP.
  • Example 1 a lithium secondary battery of Example 1 was obtained.
  • Example 2 A lithium secondary battery having the same configuration (FIG. 13) was produced in the same manner as in Example 1 except that the thickness of the porous insulating layer was 2 ⁇ m. The porosity of the porous insulating layer was 48%.
  • Example 3 A lithium secondary battery having the same configuration (FIG. 13) was produced in the same manner as in Example 1 except that the thickness of the porous insulating layer was 4 ⁇ m. The porosity of the porous insulating layer was 47%.
  • Example 4 A lithium secondary battery having the same configuration (FIG. 13) was produced in the same manner as in Example 1 except that the thickness of the porous insulating layer was 6 ⁇ m. The porosity of the porous insulating layer was 47%.
  • Example 5 In Example 5, instead of forming a porous insulating layer on the positive electrode active material layer, a porous insulating layer was formed on the separator. Other configurations and manufacturing methods of the lithium secondary battery are the same as those of the first embodiment.
  • Example 5 a porous insulating layer containing a heat resistant resin and an inorganic oxide was formed on a polyolefin separator. A forming method will be described below.
  • the aramid resin was completely heated and dissolved in NMP to obtain an aramid resin solution.
  • 6.5 g of dry anhydrous calcium chloride was added per 100 g of NMP.
  • PPD paraphenylenediamine
  • the reaction vessel was placed in a constant temperature bath at 20 ° C., and terephthalic acid dichloride (manufactured by Mitsui Chemicals, Inc.) (hereinafter referred to as TPC) was added dropwise little by little over 1 hour. Phenylene terephthalamide (hereinafter referred to as PPTA) was synthesized. At this time, 5.8 g of TPC was added per 100 g of an aramid resin solution containing anhydrous calcium chloride and PPD. Thereafter, the reaction was completed by leaving it in a thermostatic bath for 1 hour, and then replaced with a vacuum bath and stirred for 30 minutes under reduced pressure to deaerate to obtain a polymerization solution.
  • TPC terephthalic acid dichloride
  • PPTA Phenylene terephthalamide
  • the obtained polymerization solution was further diluted with an NMP solution containing calcium chloride to obtain an aramid resin solution having a PPTA concentration of 1.4 wt%.
  • an NMP solution containing calcium chloride to obtain an aramid resin solution having a PPTA concentration of 1.4 wt%.
  • 200 g of alumina particles having an average particle size of 0.1 ⁇ m was added per 100 g of aramid resin solid component.
  • an aramid resin solution after adding alumina particles was thinly applied to one side of a porous polyethylene (polyethylene microporous film) having a thickness of 16 ⁇ m with a bar coater. Thereafter, hot air at 80 ° C. was applied to the coated surface to dry the aramid resin solution to obtain a resin film. Subsequently, the resin film was sufficiently washed with pure water to remove calcium chloride and then dried. As a result, a 20 ⁇ m thick laminate having a structure in which a porous insulating layer having a thickness of 4 ⁇ m and a separator (polyethylene microporous film) having a thickness of 16 ⁇ m was laminated was obtained. The average porosity of the porous insulator was 48%.
  • the above laminate was disposed between the positive electrode plate and the negative electrode plate so that the porous insulating layer and the positive electrode active material layer were opposed to each other to constitute an electrode group.
  • the structure of the electrode group in the lithium secondary battery of Example 5 is shown in FIG.
  • FIG. 14 the same components as those in FIG. Using this electrode group, a lithium secondary battery was produced in the same manner as in Example 1.
  • ⁇ Comparative Example 2> A method similar to Comparative Example 1 except that a polyethylene microporous membrane (separator, trade name: hypopore, thickness: 20 ⁇ m, porosity: 42%, manufactured by Asahi Kasei Co., Ltd.) having a thickness of 20 ⁇ m is used as the separator. Thus, a lithium secondary battery having the same configuration (FIG. 15) was produced.
  • Examples 1 to 5 and Comparative Examples 1 and 2 a plurality of lithium secondary batteries including cells for safety evaluation and charge / discharge cycle characteristic evaluation were manufactured.
  • an iron nail (diameter: 2 mm) was inserted into the lithium secondary battery at a speed of 0.1 mm / second. Penetrated. The nail penetrated the electrode group along the normal direction of the negative electrode plate, and as a result, a short circuit occurred between the positive electrode and the negative electrode.
  • the volume change (expansion coefficient) due to charging / discharging of the negative electrode active material body was determined, and both were 290%.
  • the volume change of the active material body was (Vc ⁇ Vd) / Vd ⁇ 100 (%), where Vd is the volume of the active material body during discharge and Vc is the volume of the active material body during charging.
  • the volume Vd of the active material body at the time of discharge is obtained from the thickness and porosity of the negative electrode active material layer at the time of discharge (ratio of the volume occupied by the gap between the active material bodies in the entire negative electrode active material layer).
  • the volume Vc of the negative electrode active material layer during charging was determined from the thickness of the negative electrode active material layer (the porosity of the negative electrode active material layer during charging was zero).
  • the amount of heat generated by the lithium secondary battery when an internal short-circuit occurred was determined by providing a porous insulating layer of 1 ⁇ m or more on the positive electrode surface (Examples 1 to 5). It turned out that it can reduce from 1 and 2. This is presumably because in the lithium secondary batteries of Examples 1 to 5, the progress of short circuit is suppressed by the porous insulating layer, and the oxidation reaction of the negative electrode is suppressed. Moreover, when the porous insulating layer was thickened, the amount of heat generation tended to be further reduced. Furthermore, it has been found that even when a porous insulating layer is provided on the separator, the amount of heat generation can be reduced.
  • the lithium secondary batteries of the comparative example and the example were disassembled, and in the comparative example, it was confirmed by visual observation that the positive electrode active material was dropped. On the other hand, in the Examples, the positive electrode active material was hardly removed. Therefore, in the examples, as described above with reference to FIG. 2 and FIG. 3, the porous insulating layer suppresses the falling off of the positive electrode active material due to the volume change of the negative electrode, thereby improving the cycle life. It is thought that. In addition, as described above with reference to FIG. 6, in Examples 1 to 5, it is considered that the decrease in the electrolyte solution on the positive electrode side due to repeated charge and discharge was suppressed by the porous insulating layer. Moreover, when the porous insulating layer was thickened, the charge / discharge cycle characteristics could be further improved. Furthermore, it was confirmed that the same effect was obtained regardless of the position of the porous insulating layer.
  • the thickness of the separator in Comparative Example 2 is equal to the total thickness of the separator and the porous insulating layer in Examples 3 and 5 (20 ⁇ m). Therefore, it is considered that the capacities of Comparative Example 2 and Examples 3 and 5 are substantially equal. From this, it was also found that by providing the porous insulating layer, the amount of heat generated by an internal short circuit can be suppressed and the charge / discharge cycle characteristics can be improved without reducing the capacity.
  • the wettability was evaluated as follows. First, a drop of the electrolyte was dropped on the surface of the test body (positive electrode plate or separator), and the time change rate of the contact angle was measured. The time change rate of the contact angle was calculated from the contact angle immediately after dropping of the electrolytic solution and the contact angle 10 seconds after dropping. Here, the contact angle was measured twice, and the average value was obtained. As the electrolytic solution used in this evaluation test, the electrolytic solution used in Example 3 and Comparative Example 1 was used. In addition, this evaluation test was performed at a temperature of 25 ° C.
  • the porous insulating layer had higher wettability than the positive electrode active material layer. Therefore, in the lithium secondary battery of Example 3, by providing the porous insulating layer on the positive electrode active material layer, the effect of holding the electrolyte solution on the positive electrode side is enhanced as compared with the lithium secondary battery of Comparative Example 1. It was confirmed.
  • Example B Examples 6 and 7, Comparative Example 3
  • Example B a lithium secondary battery was produced using an electrolyte different from the electrolyte used in Example A described above, and the charge / discharge cycle characteristics were evaluated.
  • LiPF 6 As an electrolytic solution, LiPF 6 was dissolved at a concentration of 1.4 mol / L in a solvent in which ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DMC) were mixed at a volume ratio of 1: 1: 8. A non-aqueous electrolyte was used. The ionic conductivity was 10.7 mS / cm and the viscosity was 2.9 cP.
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DMC diethyl carbonate
  • a lithium secondary battery having the same configuration (FIG. 13) was produced in the same manner as in Example 1 except for the thickness of the electrolytic solution and the porous insulating layer.
  • Example 7 A lithium secondary battery having the same configuration (FIG. 13) was produced in the same manner as in Example 6 except that the thickness of the porous insulating layer was 4 ⁇ m.
  • the wettability of the porous insulating layer is higher than the wettability of the positive electrode active material layer, as in the previous examples. Therefore, it was found that charge / discharge cycle characteristics can be improved by providing a porous insulating layer having high wettability with respect to the electrolyte regardless of the type of the electrolyte.
  • Examples 6 and 7 were higher than those of Examples 1 to 5. This is because the electrolytes used in Examples 6 and 7 have higher ionic conductivity and lower viscosity than the electrolytes used in Examples 1 to 5, and thus lithium ions can be moved more easily. it is conceivable that.
  • the lithium secondary battery of the present invention can be used for the same applications as conventional lithium secondary batteries.
  • it is useful as a power source for portable electronic devices such as personal computers, mobile phones, mobile devices, personal digital assistants (PDAs), portable game devices, and video cameras.
  • PDAs personal digital assistants
  • it is expected to be used as a secondary battery for assisting an electric motor, a power tool, a cleaner, a power source for driving a robot, a power source for a plug-in HEV, etc. in a hybrid electric vehicle, a fuel cell vehicle and the like.
  • Negative electrode current collector 100, 200 Lithium secondary battery 30 Positive electrode 31 Positive electrode current collector 33 Positive electrode active material layer 20 Negative electrode 21 Negative electrode current collector 21a Surface of negative electrode current collector (portion where convex portions are not formed) 22 Protrusions 23 Negative electrode active material layer 24 Active material body 13 Separator 15, 15a, 15b Porous insulating layer 18 Positive electrode lead 19 Negative electrode lead 16 Gasket 17 Exterior case 24 Columnar body 50 Electron beam deposition apparatus 51 Chamber 52 First piping 53 Fixed base 54 Nozzle 55 Target 56 Power supply

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

L'invention concerne une batterie secondaire au lithium (100) comprenant une électrode positive (30), une électrode négative (20), un séparateur (13) disposé entre l'électrode positive (30) et l'électrode négative (20), et une solution électrolytique présentant une conductivité vis-à-vis des ions lithium, dans laquelle l'électrode négative (20) comprend un collecteur de courant d'électrode négative (21) ayant de multiples parties convexes (22) sur sa surface et une couche de matériau actif d'électrode négative (23) formée sur le collecteur de courant d'électrode négative (21) et contenant de multiples corps de matériau actif (24), dans laquelle les multiples corps de matériau actif (24) sont respectivement placés sur les parties convexes (22) dans le collecteur de courant d'électrode négative (21) et contiennent un matériau actif en alliage contenant du silicium ou de l'étain en tant que matériau actif d'électrode négative, et dans laquelle une couche isolante poreuse (15) principalement constituée d'un oxyde inorganique est disposée entre l'électrode positive (30) et l'électrode négative (20).
PCT/JP2011/001502 2010-03-18 2011-03-15 Batterie secondaire au lithium Ceased WO2011114709A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010062499 2010-03-18
JP2010-062499 2010-03-18

Publications (1)

Publication Number Publication Date
WO2011114709A1 true WO2011114709A1 (fr) 2011-09-22

Family

ID=44648821

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/001502 Ceased WO2011114709A1 (fr) 2010-03-18 2011-03-15 Batterie secondaire au lithium

Country Status (1)

Country Link
WO (1) WO2011114709A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016194589A1 (fr) * 2015-05-29 2016-12-08 日立マクセル株式会社 Batterie secondaire au lithium-ion
CN109478631A (zh) * 2016-07-28 2019-03-15 松下知识产权经营株式会社 非水电解质二次电池
CN110247102A (zh) * 2018-03-09 2019-09-17 松下知识产权经营株式会社 锂二次电池
CN110556564A (zh) * 2018-05-31 2019-12-10 松下知识产权经营株式会社 锂二次电池
CN110556567A (zh) * 2018-05-31 2019-12-10 松下知识产权经营株式会社 锂二次电池
CN112673504A (zh) * 2018-09-28 2021-04-16 松下知识产权经营株式会社 锂二次电池
JP2021077641A (ja) * 2019-11-11 2021-05-20 株式会社Ｇｓユアサ 蓄電素子
CN112913050A (zh) * 2018-10-30 2021-06-04 日本碍子株式会社 纽扣型二次电池

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007012421A (ja) * 2005-06-30 2007-01-18 Matsushita Electric Ind Co Ltd リチウムイオン電池用負極およびそれを用いたリチウムイオン電池
JP2008255202A (ja) * 2007-04-04 2008-10-23 Asahi Kasei Chemicals Corp 複合微多孔膜、電池用セパレータ、及び複合微多孔膜の製造方法
JP2008258154A (ja) * 2007-03-13 2008-10-23 Matsushita Electric Ind Co Ltd リチウム二次電池用負極およびその製造方法、ならびにリチウム二次電池用負極を備えたリチウム二次電池
JP2009238752A (ja) * 2008-03-27 2009-10-15 Samsung Sdi Co Ltd 電極組立体及びこれを具備する二次電池
JP2009272153A (ja) * 2008-05-08 2009-11-19 Hitachi Maxell Ltd リチウム二次電池
JP2009283273A (ja) * 2008-05-22 2009-12-03 Hitachi Maxell Ltd 電池用セパレータおよび電池

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007012421A (ja) * 2005-06-30 2007-01-18 Matsushita Electric Ind Co Ltd リチウムイオン電池用負極およびそれを用いたリチウムイオン電池
JP2008258154A (ja) * 2007-03-13 2008-10-23 Matsushita Electric Ind Co Ltd リチウム二次電池用負極およびその製造方法、ならびにリチウム二次電池用負極を備えたリチウム二次電池
JP2008255202A (ja) * 2007-04-04 2008-10-23 Asahi Kasei Chemicals Corp 複合微多孔膜、電池用セパレータ、及び複合微多孔膜の製造方法
JP2009238752A (ja) * 2008-03-27 2009-10-15 Samsung Sdi Co Ltd 電極組立体及びこれを具備する二次電池
JP2009272153A (ja) * 2008-05-08 2009-11-19 Hitachi Maxell Ltd リチウム二次電池
JP2009283273A (ja) * 2008-05-22 2009-12-03 Hitachi Maxell Ltd 電池用セパレータおよび電池

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016194589A1 (fr) * 2015-05-29 2016-12-08 日立マクセル株式会社 Batterie secondaire au lithium-ion
JPWO2016194589A1 (ja) * 2015-05-29 2018-03-15 マクセルホールディングス株式会社 リチウムイオン二次電池
CN109478631A (zh) * 2016-07-28 2019-03-15 松下知识产权经营株式会社 非水电解质二次电池
CN110247102A (zh) * 2018-03-09 2019-09-17 松下知识产权经营株式会社 锂二次电池
CN110247102B (zh) * 2018-03-09 2024-03-08 松下知识产权经营株式会社 锂二次电池
CN110556564A (zh) * 2018-05-31 2019-12-10 松下知识产权经营株式会社 锂二次电池
CN110556567A (zh) * 2018-05-31 2019-12-10 松下知识产权经营株式会社 锂二次电池
CN112673504A (zh) * 2018-09-28 2021-04-16 松下知识产权经营株式会社 锂二次电池
CN112673504B (zh) * 2018-09-28 2024-03-01 松下知识产权经营株式会社 锂二次电池
CN112913050A (zh) * 2018-10-30 2021-06-04 日本碍子株式会社 纽扣型二次电池
JP2021077641A (ja) * 2019-11-11 2021-05-20 株式会社Ｇｓユアサ 蓄電素子

Similar Documents

Publication Publication Date Title
JP5231557B2 (ja) 非水電解質二次電池用負極及び非水電解質二次電池
CN101960654B (zh) 非水电解质二次电池用负极以及非水电解质二次电池
JP5378720B2 (ja) リチウムイオン二次電池
JP5313761B2 (ja) リチウムイオン電池
CN101425579B (zh) 负极活性物质、负极以及电池
KR100901048B1 (ko) 비수 전해질 이차 전지
CN101232090B (zh) 锂离子二次电池用负极以及锂离子二次电池
JP2010097843A (ja) リチウムイオン二次電池
JP2010250968A (ja) リチウムイオン二次電池
JP4594965B2 (ja) リチウムイオン二次電池用負極集電体、リチウムイオン二次電池用負極およびリチウムイオン二次電池
CN101572300B (zh) 负极和锂离子二次电池
JP2010073571A (ja) リチウムイオン二次電池およびその製造方法
WO2011114709A1 (fr) Batterie secondaire au lithium
WO2008044683A1 (fr) Électrode négative pour accumulateur secondaire à électrolyte non aqueux
JP2009266737A (ja) リチウムイオン二次電池およびその製造方法
JP2009295289A (ja) リチウムイオン二次電池およびその製造方法
JP2009016310A (ja) 集電体、電極および非水電解質二次電池
JP4563478B2 (ja) リチウムイオン二次電池
CN105934840A (zh) 电器件
JP2016184484A (ja) リチウムイオン二次電池用負極およびリチウムイオン二次電池
JP2010049968A (ja) 固体電解質二次電池
JP2010287466A (ja) 非水電解質二次電池
JP2011014426A (ja) 非水電解質二次電池用負極および非水電解質二次電池
JP2013069503A (ja) リチウム二次電池および負極
JP2008258139A (ja) 非水電解質二次電池用負極とその製造方法およびそれを用いた非水電解質二次電池

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11755900

Country of ref document: EP

Kind code of ref document: A1

DPE2 Request for preliminary examination filed before expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11755900

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP