JP2010205693A - Method for manufacturing electrode with collection layer, electrode with collection layer, and battery - Google Patents

Abstract

An object of the present invention is to easily form a main current collecting layer interposed between a pair of electrode layers serving as one electrode of a cell and a connecting current collecting layer for connecting main current collecting layers of a plurality of stacked cells. Provided is a method for producing an electrode with a current collecting layer.
A main current collecting layer interposed between a pair of electrode layers serving as one electrode of a cell and a connecting current collecting layer for connecting main current collecting layers of a plurality of stacked cells are formed. . Conductive main surface 22P on one plane of precursor 10G of the electrode layer, conductive connecting surface 24P on the side surface of precursor 10G, so that main surface 22P and connecting surface 24P are seamlessly continuous. To form. The pair of split pieces 10P formed with the main surface 22P and the connection surface 24P are joined so that the main surfaces 22P face each other and the connection surfaces 24P are adjacent to each other. The precursor 10G is sintered, and a pair of joined main surfaces 22P is used as a main current collecting layer, and a pair of adjacent connecting surfaces 24P is used as a connecting current collecting layer.
[Selection] Figure 2

Description

  The present invention relates to a battery electrode manufacturing method in which a current collecting layer is formed, the battery electrode, and a battery using the electrode. In particular, when a plurality of cells are stacked, an electrode with a current collecting layer that can easily obtain an electrode with a current collecting layer suitable for electrically connecting the current collecting layers of one electrode in each cell collectively. It relates to the manufacturing method.

  Lithium ion secondary batteries (hereinafter simply referred to as lithium secondary batteries) have a long life, high efficiency, and high capacity, and are used as power sources for mobile phones, notebook computers, digital cameras, and the like.

  A lithium secondary battery is a battery that performs charge and discharge by exchanging lithium ions between a positive electrode and a negative electrode through an electrolyte layer. As one structure of this lithium secondary battery, a stacked type in which cells having a positive electrode, a negative electrode, and an electrolyte layer interposed between the positive and negative electrodes are stacked is known (for example, see Patent Document 1). .

  This lithium secondary battery has the following configuration. A positive electrode plate and a negative electrode plate having a rectangular planar shape are arranged so as to intersect at a right angle, and a pole group in which an electrolyte is provided between the positive electrode plate and the negative electrode plate is arranged on an insulating substrate. The electrode extraction part provided at both ends of the positive electrode plate is connected to the positive electrode terminal formed on the insulating substrate via the positive electrode strap electrode. Electrode extraction portions provided at both ends of the negative electrode plate are connected to a negative electrode terminal formed on the insulating substrate via a negative electrode strap electrode. Then, the lid is bonded and sealed to the insulating substrate so as to surround the pole group.

  This lithium secondary battery has a substantially square shape when seen in a plan view, and by arranging the rectangular positive electrode plate and the negative electrode plate so as to cross each other, the electrode extraction portion of the positive electrode plate has one side of the square with respect to the negative electrode plate. The electrode extraction part of the negative electrode plate is protruded to the side adjacent to the square with respect to the positive electrode plate. Therefore, the positive electrode strap electrode does not contact the negative electrode plate, and the negative electrode strap electrode does not contact the positive electrode plate.

Japanese Patent Laid-Open No. 2003-203671

  However, a method for easily manufacturing a battery configuration for collecting current from a pole group has not been proposed. In the above lithium secondary battery, in order to collect current from the stacked electrode group, formation of electrode extraction portions on the positive electrode plate and the negative electrode plate, formation of positive electrode terminals and negative electrode terminals on the insulating substrate, these electrode extraction portions and It is necessary to connect the terminals via the strap electrodes. Therefore, the manufacturing process of the battery is complicated and the cost is increased.

  In addition, in a battery in which a plurality of cells are stacked, an appropriate electrode configuration for collecting current from a positive electrode group or a negative electrode group without increasing the battery size has not been proposed. In the above lithium secondary battery, since the rectangular positive electrode plate and the negative electrode plate are crossed at right angles, the electrode extraction portion of the positive electrode plate protrudes from the negative electrode plate or the electrolyte layer, and the electrode extraction portion of the negative electrode plate is It protrudes from the positive electrode plate and the electrolyte layer. These electrode extraction portions do not contribute to the battery reaction, and the size of the battery must be considerably larger than the overlapping portion of the positive electrode plate, the electrolyte layer, and the negative electrode plate, which are regions where the battery reaction is actually performed. As a result, the presence of the electrode extraction part and the strap electrode becomes an obstacle to the miniaturization of the battery.

  The present invention has been made in view of the above circumstances, and one of its purposes is that a main current collecting layer interposed between a pair of electrode layers serving as one electrode of a cell and a main of a plurality of stacked cells. An object of the present invention is to provide a method for producing an electrode with a current collecting layer that can easily form a current collecting layer for connecting current collecting layers.

  Another object of the present invention is to connect a main current collecting layer interposed between a pair of electrode layers serving as one electrode of a cell and a main current collecting layer of a plurality of stacked cells. It is an object of the present invention to provide an electrode with a current collecting layer that can be reduced in size and that is reliably connected to a main current collecting layer and a current collecting layer for connection.

  Furthermore, another object of the present invention is to provide a battery that can be miniaturized using the battery electrode of the present invention.

(1) The manufacturing method of the electrode with a current collection layer of this invention connects the main current collection layer interposed between a pair of electrode layer used as one electrode of a cell, and the main current collection layers of several laminated | stacked cells The present invention relates to a method of forming a current collecting layer for connection, and includes the following steps.
Forming process of main surface and connection surface: Conductive main surface on one plane of electrode layer or electrode layer precursor, conductive connection surface on side surface of electrode layer or electrode layer precursor, these The main surface and the connection surface are formed so as to be seamless.
Bonding step of electrode layer or electrode layer precursor: The pair of electrode layers or electrode layer precursors on which the main surface and the connection surface are formed, such that the main surfaces face each other and the connection surfaces are adjacent to each other. The pair of joined main surfaces are used as a main current collecting layer, and the adjacent pair of connecting surfaces are used as a connecting current collecting layer.
Sintering step: When the formation target of the main surface and the connection surface is the precursor, the precursor is sintered.

  According to this structure, the electrode with a current collection layer which has the main current collection layer interposed between a pair of electrode layers, and the current collection layer for connection closely_contact | adhered to the side surface of an electrode layer can be manufactured easily. In addition, since the main current collecting layer and the connecting current collecting layer are continuously formed without seams, the electrical connection between them can be ensured as compared with the case where they are formed individually.

(2) The following configuration is preferable as an embodiment of the method for producing an electrode of the present invention.
A step of preparing a planar electrode layer or a precursor of the electrode layer, and a step of forming a recess in the electrode layer or the precursor of the electrode layer.
Further, the step of forming the main surface and the connection surface includes the following steps.
Conductive fluid application process: The conductive fluid that serves as the main surface and the connection surface is applied from one plane of the electrode layer or the precursor of the electrode layer to the inner surface of the recess.
Splitting process of electrode layer or electrode layer precursor: The electrode layer or the electrode layer precursor is divided into a plurality of divided pieces at the position of the concave portion, and the main surface is formed on one plane of each divided piece, and the inner surface of the concave portion. The process of generating the connection surface on the side of the split piece.
The step of joining the pair of electrode layers or the electrode layer precursor is performed by joining the split pieces so that the main surfaces of the pair of split pieces face each other and the connection surfaces are adjacent to each other.

  According to this configuration, a single electrode layer coated with a conductive fluid in a predetermined region is divided into a plurality of divided pieces, and the pair of divided pieces are joined together, so that the main layer interposed between the pair of electrode layers. An electrode with a current collecting layer having a current collecting layer and a current collecting layer for connection closely attached to the side surface of the electrode layer can be more easily and efficiently produced.

  (3) As one embodiment in the method for producing an electrode of the present invention, in the step of forming the recess, a through-hole penetrating the front and back of the electrode layer or the precursor of the electrode layer is formed as the recess, and the conductive fluid is used. The applying step is preferably performed while sucking from the side opposite to the main surface of the through hole.

  According to this configuration, by applying the conductive fluid while sucking from the side opposite to the main surface of the through hole, it is possible to easily apply the conductive fluid to the inner side surface of the recess.

  (4) As one embodiment in the method for producing an electrode of the present invention, when the formation target of the main surface and the connection surface is the precursor, the step of sintering the precursor is a pair of precursors joined. This can be done later.

  According to this structure, it is hard to produce damages, such as a crack, in a precursor at the time of the said joining, and the electrode layer with a current collection layer which consists of a sintered compact can be formed easily. An electrode having an electrode layer made of such a sintered body can be suitably used for an all-solid-state nonaqueous electrolyte battery.

  (5) As one embodiment in the method of manufacturing an electrode of the present invention, the main surface and the connection surface are made of any metal selected from the group consisting of Ag, Cu, Ni and Pd, or any metal. It is preferable to include a main alloy.

  These metals and alloys are suitable for forming the main current collecting layer and the connecting current collecting layer continuously.

  (6) The electrode with a current collecting layer of the present invention includes a pair of electrode layers serving as one electrode of a cell, a main current collecting layer interposed between these electrode layers, and a main current collecting of a plurality of stacked cells. It is related with the electrode with a current collection layer provided with the current collection layer for a connection for connecting layers. In this electrode, the current collecting layer for connection is in close contact with the side surfaces of the pair of electrode layers, and the main current collecting layer and the current collecting layer for connection are made of the same material and are seamless. It is characterized by.

  According to this configuration, the main current collecting layer is interposed between the electrode layers, and the connecting current collecting layer connected to the main current collecting layer is in close contact with the side surface of the electrode layer. The current collecting layer for connection does not protrude greatly. Therefore, when a battery is configured by stacking cells using the electrode with the current collecting layer, an increase in battery size can be avoided. In addition, since the main current collecting layer and the current collecting layer for connection are formed continuously and seamlessly, the electrical connection between the two current collecting layers can be stably maintained.

  (7) The battery of the present invention relates to a battery in which a plurality of cells are stacked. In this battery, each cell includes an electrode with a current collecting layer, the other electrode paired with the electrode layer included in the electrode, and an electrolyte layer interposed between the electrodes. Here, let the said electrode with a current collection layer for batteries be the electrode with a current collection layer of the said invention. And it is further provided with the connection conductor which connects the current collection layers for connection of each cell.

  According to this configuration, by using the electrode with a current collecting layer of the present invention, the battery in which a plurality of cells are stacked can be reduced in size, and electrical connection between the main current collecting layer and the current collecting layer for connection is achieved. A reliable battery can be obtained.

  According to the method for manufacturing an electrode with a current collecting layer of the present invention, a main current collecting layer interposed between a pair of electrode layers that are one electrode of a cell and the main current collecting layers of a plurality of stacked cells are connected to each other. Therefore, an electrode with a current collecting layer having a current collecting layer for connection can be easily produced.

  According to the electrode with a current collecting layer of the present invention, a small battery in which a plurality of cells are stacked can be configured.

  According to the battery of the present invention, the battery size can be reduced.

It is sectional drawing which shows an example of the electrode with a current collection layer which concerns on embodiment of this invention. It is a perspective view and a sectional view showing an example of a manufacturing method of an electrode with a current collection layer concerning an embodiment of the present invention, (A) is a precursor of an electrode layer, (B) is at the time of formation of a main surface and a connection surface, ( C) shows each stage during precursor splitting, and (D) shows each stage during precursor joining. (A) is sectional drawing which shows an example of the cell using the electrode with a current collection layer which concerns on this invention, (B) is a fragmentary sectional view which shows the battery which laminated | stacked the several cell. It is the perspective view and sectional drawing which show an example of the manufacturing method of the electrode with a current collection layer which concerns on the modification 1 of this invention, (A) is a precursor, (B) is the time of formation of a main surface and a connection surface, (C) Indicates the stage during precursor splitting, and (D) indicates each stage during precursor bonding.

  Hereinafter, embodiments of an electrode with a current collecting layer according to the present invention, a method for manufacturing the electrode, a cell using the electrode, and a battery in which the cell is stacked will be described in order based on FIGS. Here, the following description will be given by taking as an example the case of producing an electrode with a current collecting layer to be a positive electrode of a lithium ion secondary battery. However, the present invention can be similarly applied to an electrode with a current collecting layer serving as a negative electrode.

[Electrode with current collecting layer]
As shown in FIG. 1, an electrode with a current collecting layer (here, a positive electrode) 100 according to the present invention has a main current collecting layer 22 interposed between a pair of electrode layers 10, and a connecting current collector is formed on the side surfaces of both electrode layers 10. The electric layer 24 is in close contact.

The pair of electrode layers 10 constitutes one electrode (here, positive electrode) of the cell. The pair of electrode layers 10 is preferably composed of a sintered body. If the electrode layer 10 is a sintered body, it is relatively excellent in rigidity, and other battery components such as an electrolyte layer can be easily formed on the electrode layer 10. Examples of the active material contained in the electrode layer 10 (positive electrode layer) include LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiCo _1/3 Ni _1/3 Mn _1/3 O _{2, and the} like. it can. These electrode layers 10 may contain a conductive additive such as carbon black.

  On the other hand, the current collecting layer 20 for collecting current from both electrode layers 10 includes a main current collecting layer 22 and a connecting current collecting layer 24. The main current collecting layer 22 is interposed between the pair of electrode layers 10 to efficiently collect current from a wide area of the electrode layer 10. The current collecting layer 24 for connection has a function of a terminal surface for electrically connecting the main current collecting layers 22 of each cell when a plurality of cells constituted by the electrodes 100 with the current collecting layer are stacked. The main current collecting layer 22 and the connecting current collecting layer 24 are made of a conductive material having excellent conductivity, such as Ag, Cu, Ni, and Pd.

  Here, the main current collecting layer 22 and the connecting current collecting layer 24 are made of the same material, and are configured such that both the current collecting layers 22 and 24 are seamlessly continuous. By configuring the current collecting layers 22 and 24 with the same material so as to be seamless, the current collecting layers 22 and 24 can be securely connected to each other. In particular, the main current collecting layer 22 and the connecting current collecting layer 24 are bent and connected so as to cover the ridgeline formed by one flat surface and the side surface of each electrode layer 10, but the bent portion has no seam. Therefore, compared to the case where the main current collecting layer 22 and the current collecting layer 24 for connection are individually manufactured and connected, both the current collecting layers 22 and 24 are reliably reliable both mechanically and electrically. It can be said that it is connected.

  Further, as will be described later, the main current collecting layer 22 is configured by joining a pair of main surfaces provided in each of the pair of electrode layers 10. On the other hand, the current collecting layer 24 for connection is configured by adjoining a pair of connection surfaces provided in each of the pair of electrode layers 10 in the creeping direction. Therefore, the thickness of the main current collecting layer 22 is usually about twice the thickness of the current collecting layer 24 for connection.

  Furthermore, since the current collecting layer 24 for connection is formed in close contact with the side surface of the electrode layer 10, the thickness of the current collecting layer 24 for connection is in addition to the structure in which the current collecting layer 24 for connection is not easily damaged. Only the portion protrudes to the side of the electrode layer 10. Therefore, when a battery is configured using the electrode 100 with the current collecting layer, an increase in battery size can be suppressed as much as possible.

  In addition, since the main current collection layer 22 is configured by joining a pair of main surfaces formed on each electrode layer 10, when a boundary surface is recognized at an approximately middle portion in the thickness direction of the main current collection layer 22 There is. Further, since the current collecting layer 24 for connection is configured by adjoining a pair of connection surfaces formed on each electrode layer 10, a boundary surface is recognized at a substantially intermediate portion in the creeping direction of the current collecting layer 24 for connection. May be.

[Method for producing electrode with current collecting layer]
The manufacturing method of the electrode with a current collecting layer according to the present invention mainly includes “preparation of electrode layer precursor”, “formation of main surface and connection surface”, “joining of precursor”, and “sintering of precursor”. Prepare as a process.

<Preparation of electrode layer precursor>
In order to obtain the electrode of the present invention, a pair of electrode layer precursors 10G is used. A green sheet is preferably used as the precursor 10G. The green sheet is obtained by mixing an active material powder and a binder solution to prepare a slurry, and then forming the slurry into a sheet shape, which is then sintered to form an electrode layer. In order to form the green sheet from the slurry, an appropriate method such as a doctor blade, a die coater, or a squeegee may be used.

  Usually, a rectangular or square sheet is preferably used as the precursor 10G, but various polygons such as rhombus, trapezoid, parallelogram, triangle, hexagon, circle, ellipse, and the like may be used. .

  The pair of precursors 10G of the electrode layer may be prepared from the beginning as a pair of precursors 10G, or may be obtained through a process of dividing one precursor 10G into two. When dividing one precursor 10G, it is easy to divide, and one side of the precursor (divided piece 10P) after the division can be formed with a connection surface 24P as a current collecting layer for connection. It is preferable to form a recess 10H in the precursor 10G (see FIG. 2A). The recess 10H here is a through-hole through which the precursor 10G passes through on both sides as shown in FIG. 2 (A). Examples of the other recess 10H include a non-penetrating recess formed on one side of the precursor 10G, as shown in FIG. Regardless of the configuration of the through hole or the depression, the inner side surface of the recess 10 becomes the side surface of the divided precursor 10G. Typically, since a rectangular material is used as the precursor 10G before division, the concave portion 10H is preferably formed along the short side of the rectangle so that the long side of the rectangle is equally divided. If such a recess 10H is formed, the size of each divided piece 10P can be made constant. Further, since the recess 10H serves as a starting point when the precursor 10G is divided, it is preferable to form the recess 10H in a linear shape. In particular, it is preferable to form the recess 10H so that the precursor 10G can be divided into an even number of divided pieces 10P. Since the electrode of the present invention is manufactured using a pair of precursors 10G, if an even number of divided pieces 10P are obtained, the electrodes can be configured without excess or deficiency of the precursor 10G by combining the divided pieces 10P for each pair. .

  In order to form the concave portion 10H in the precursor 10G, when using a green sheet, the slurry is removed only at the portion that becomes the concave portion of the formed green sheet, or the slurry is shielded from being supplied to the portion that becomes the concave portion of the green sheet. And forming a green sheet.

<Formation of main surface and connection surface>
When the precursor 10G is obtained, as shown in FIG. 2 (B), a main surface 22P to be a main current collecting layer is formed on one plane (upper surface or lower surface) of the precursor 10G, and the side surface of the precursor 10G is formed. A connection surface 24P to be a current collecting layer for connection is formed in The main surface 22P and the connection surface 24P are formed so as to be continuous without a joint. The main surface 22P and the connection surface 24P are preferably formed by applying a conductive fluid onto a predetermined surface of the precursor 10G. If the conductive fluid is applied, the main surface 22P and the connection surface 24P can be continuously and efficiently formed on the precursor 10G in one step. As the conductive fluid, a conductive paste, for example, a metal paste containing Ag, Cu, Ni, Pd or the like can be suitably used.

  The conductive fluid may be applied by an appropriate method such as screen printing, doctor blade, or squeegee.

  When a single precursor 10G that is not divided is used, the position on the precursor 10G to which the conductive fluid is applied is one plane of the precursor 10G and a side surface that follows the plane. Normally, if a conductive fluid is applied to one plane of the precursor 10G and the fluid is spread to the outer edge of the precursor 10G, the conductive fluid flows from the plane of the precursor 10G to the side, and both the plane and the side The conductive fluid can be applied continuously and seamlessly.

  When using the precursor 10G provided with the recess 10H to be divided later, it is the same as applying the conductive fluid to one plane of the precursor 10G, but applying the conductive fluid to the side surface of the precursor 10G. Instead, a conductive fluid is applied to the inner surface of the recess 10H. The application of the conductive fluid to the inner surface of the recess 10H is realized by spreading the conductive fluid applied to the flat surface of the precursor 10G to the opening of the recess 10H so that the conductive fluid flows into the recess 10H. . The inner width of the recess 10H may be selected to be an appropriate inner width so that the conductive fluid is covered on each inner surface of the recess 10H and does not fill the entire area of the recess 10H. In particular, if the recess 10H is a through hole, the conductive fluid is drawn into the through hole and attached to the inner surface of the recess by sucking the through hole from the surface opposite to the surface forming the main surface 22P of the precursor 10G. The connecting surface 24P having a uniform thickness can be formed.

  Further, regardless of the presence or absence of the recess 10H, in any precursor 10G, the conductive fluid may be applied to the entire surface of one plane and the side surface (the inner surface of the recess) of the precursor 10G, or only a part thereof may be applied. You don't have to. If a connection surface is formed on the entire side surface of the precursor 10G, a connection conductor (described later with reference to FIG. 3B) connected to the current collecting layer 24 (FIG. 1) when a plurality of cells are stacked later. Can be connected anywhere on the side of the electrode. On the other hand, if the connection surface 24P is formed only on a part of the side surface of the precursor 10G, the connection position of the connection conductor of the positive electrode is limited, but the positive electrode of this example is combined with the negative electrode having the main surface and the connection surface When the battery is configured, the connecting conductor connecting the connecting surfaces of the negative electrode and the connecting conductor of the positive electrode can be arranged in parallel on the same side of the positive and negative electrodes. That is, the negative connection conductor can be disposed at a location where the positive side surface has no connection surface. Therefore, both connecting conductors protrude only on one side of the positive and negative electrodes, and the battery can be miniaturized. Further, since the connecting conductors of the positive and negative electrodes are arranged together on one side of the positive and negative electrodes, it is not necessary to route one connecting conductor and bring it close to the other connecting conductor side, and to the outside in close proximity to both connecting conductors. Since a connection unit with the device can be formed, the battery structure including the connection unit can also be saved.

  The thickness for applying the conductive fluid is preferably the same for each of the main surface 22P and the connection surface 24P of each precursor 10G. This is because if the thickness of the conductive fluid is different between one precursor 10G (10P) and the other precursor 10G (10P), a step is formed on the connection surface 24P when the pair of precursors 10G is joined later. .

  In addition, a conductive fluid (mixed fluid) in which an active material used for the precursor 10G is mixed may be applied to a predetermined position of the precursor 10G. For example, a mixed fluid is applied on a predetermined surface of the precursor 10G, and a conductive fluid is further applied on a layer of the mixed fluid. According to such a configuration, the precursor 10G, the mixed layer of the active material and the conductive fluid, and the conductive fluid layer are sequentially formed. That is, since a mixed layer in which substances constituting both layers are mixed is formed between the precursor 10G and the conductive fluid layer, the adhesion between the conductive fluid and the precursor 10G can be improved. Even when this mixed fluid is applied, the fluid is preferably sucked from the side opposite to the main surface of the through hole.

<Division of precursor>
When a plurality of precursors are obtained by dividing one precursor 10G, the precursor 10G is divided. This division is performed at the position of the recess 10H formed in the precursor 10G in advance after the formation of the main surface 22P and the connection surface 24P. The portion that was the inner side surface of the recess 10H before the division becomes the side surface of the divided piece 10P, that is, the side surface of the precursor 10G. Therefore, if one precursor 10G is divided, it is possible to obtain a plurality of divided pieces 10P in which a conductive fluid is applied to one plane and side surfaces following the plane. An example of the divided piece 10P in which the main surface 22P and the connection surface 24P are formed is as shown in FIG.

<Precursor bonding>
The precursor 10G (divided piece 10P) including the main surface 22P and the connection surface 24P obtained by the above-described steps is joined. As shown in FIG. 2 (D), this bonding is performed so that the main surfaces 22P of the pair of precursors 10G (10P) face each other and the connection surfaces 24P are adjacent to each other. To match.

  This joining method is performed by pressurizing a pair of precursors 10G (10P) arranged so that the principal surfaces 22P are in surface contact with each other. The pressure at that time may be such that the main surface 22P, the precursor 10G (10P), and the main surface 22P are sufficiently in close contact with each other, and preferably about 10 to 100 MPa, for example. In addition to this pressurization, the precursors 10G (10P) may be joined by heating. By applying pressure while heating, the main surface 22P, the precursor 10G (10P), and the main surface 24P can be more fully integrated. As for this heating temperature, about 40-80 degreeC is mentioned, for example.

<Sintering of precursor>
When the pair of precursors 10G (10P) on which the main surface 22P and the connection surface 24P are formed are joined, the joined bodies are sintered. The sintering temperature is generally 800 to 1100 ° C. × 12 to 48 h, although it varies depending on the constituent material of the precursor. Through this sintering process, the green sheet becomes an electrode layer of a sintered body, and the electrode 100 with a current collecting layer shown in FIG. 1 can be obtained.

  Further, prior to this sintering, it is preferable to perform a heat treatment for removing the binder in the precursor 10G (10P). Examples of the heat treatment conditions include 300 to 500 ° C. × 12 to 48 hours.

〔cell〕
A cell is formed using the electrode with a current collecting layer obtained by the above method. The cell is a minimum unit for performing a battery reaction, and includes a positive electrode 100, a negative electrode 200, and an electrolyte layer 300 interposed between both electrodes, as shown in FIG.

<Electrolyte layer>
The electrolyte layer 300 may be formed on the surface of at least one of the pair of electrode layers 10 constituting the electrode shown in FIG. This electrolyte layer 300 is, for example, an Li-PON, Li-PSO, Li-PS, Li-La-Ti-O, or Li-La-Zr-O amorphous film composed of Li ₂ S and P ₂ S _5. Alternatively, it can be composed of a polycrystalline film or the like. The thickness of the electrolyte layer 300 is preferably about 1 to 10 μm. The electrolyte layer 10 can be formed by using a solid phase method (powder sintering method) or a gas phase method (for example, PVD method or CVD method).

<Other electrode>
Since the above-described electrode 100 with a current collecting layer (FIG. 1) functions as a positive electrode, the negative electrode 200 is formed as a counter electrode. The negative electrode 200 may be formed on the electrolyte layer 300. As the negative electrode 200, for example, one selected from the group consisting of Li metal and an element capable of forming an alloy with Li metal, or a mixture or alloy thereof can be preferably used. Examples of elements that can form an alloy with Li include Al, Si, Sn, Bi, In, and Ag. These negative electrodes 200 can have a function as a current collecting layer in the negative electrode 200 itself. The thickness of the negative electrode 200 is preferably about 0.5 to 50 μm. For forming the negative electrode 200, for example, a vapor phase method can be used. Of course, a current collecting layer (not shown) may be used separately from the negative electrode 200.

〔battery〕
By stacking a plurality of the cells described above, a battery is formed as shown in FIG.

<Cell stacking>
The obtained plurality of cells are stacked. In that case, since the negative electrode 200 is provided on the upper surface of the cell and the electrolyte layer 300 is provided on the lower surface of the cell, a plurality of cells having the same configuration can be stacked to form an assembled battery in which a large number of cells are connected in series. .

<Attaching the connecting conductor>
Then, the connecting current collecting layers 24 formed on the side surfaces of the stacked cells are connected by the connecting conductor 400 to be electrically connected. Since the connecting current collecting layer 24 is formed on the side surface of the electrode 100 serving as the positive electrode, the connecting conductor 400 may be joined to the connecting current collecting layer 24. For the connecting conductor 400, a metal tape having excellent conductivity such as copper or aluminum can be suitably used. If the thin tape-like connecting conductor 400 is used, the only thing that protrudes from the side surface of the electrode layer 10 constituting the cell is the connecting current collecting layer 24 and the connecting conductor 400, and the battery component protrudes from the side surface of the electrode layer 10. The amount to be done can be made as small as possible. In connection with it, the enlargement of a battery can be suppressed. Further, a conductive adhesive or the like may be used for joining the connecting conductor 400 and the connecting current collecting layer 24.

  The connection conductor 400 can output electricity from the main current collection layer 22 of each cell through the connection current collection layer 24. For example, the leading end of the connecting conductor 400 is connected to a tab lead (not shown).

<Modification 1>
In the method shown in FIG. 2 described above, a through hole is provided as a recess formed in the green sheet, but a non-through recess may be used as the recess instead of the through hole. This modification is shown in FIG. In FIG. 4, members common to those in FIG. 2 are denoted with the same reference numerals. In this case, first, a groove-like depression that does not penetrate through the front and back of the green sheet is formed as the recess 10H. Next, the conductive fluid may be applied to the opening side surface of the recess in the green sheet, and the conductive fluid may be applied also to the inner surface of the recess 10H. In the following steps, as in the case of FIG. 2, the green sheet is divided at the position of the recess 10H, and the divided pieces 10P are joined and sintered.

<Modification 2>
In the method shown in FIGS. 2 and 4 described above, a green sheet is used as a conductive fluid application target. Instead, an electrode layer made of a sintered body and a precursor of an electrode layer made of a temporary sintered body. Or you may use the precursor of the electrode layer which consists of a compacting body.

  When an electrode layer made of a sintered body is to be applied with a conductive fluid, for example, a green sheet having a recess is formed before applying the conductive fluid, and the conductive fluid is applied to the surface of the sintered body. Application may be mentioned. Of course, a concave part may be formed after using a flat green sheet as a sintered body, and a conductive fluid may be applied to the surface of the sintered body.

  When a precursor of an electrode layer made of a temporary sintered body is to be applied with a conductive fluid, for example, a green sheet or a green compact is temporarily sintered to form a temporary sintered body, and the temporary sintered body is electrically conductive. Apply sex fluid. When forming a recessed part in this application | coating object, either before and after temporary sintering may be sufficient at the time of formation of a recessed part. The pair of temporary sintered bodies to which the conductive fluid is applied may be joined as shown in FIG. 2 or FIG. 4D, followed by main sintering.

  When an electrode layer precursor made of a compacted body is to be applied with a conductive fluid, for example, a compacted body having a recess as shown in FIG. 2 or FIG. A conductive fluid may be applied to the body. The green compact is produced by filling an active material powder into a mold and pressurizing it. In order to obtain a green compact having a concave portion, a convex portion corresponding to the concave portion may be formed on the diamond punch of the molding die.

<Modification 3>
In the method described in FIG. 2 and FIG. 4 described above, sintering is performed after joining a pair of divided pieces of green sheets on which a main surface and a connection surface are formed. You may join pieces. Even in this case, the electrode of the present invention as shown in FIG. 1 can be obtained.

  The electrode with a current collecting layer shown in FIG. 1 and the cell shown in FIG. 3A were produced by the method shown in FIG. 2, and a plurality of cells were further stacked to produce the battery shown in FIG.

First, the following binder was dissolved in a solvent, and a positive electrode active material was mixed in the solution to prepare a slurry.
Cathode active material: LiCoO _{2 with an} average particle size of 2 μm
Binder: PVB (polyvinyl butyral), DBP (dibutyl phthalate)
Solvent: Toluene

  Next, the obtained slurry is formed into a sheet shape using a doctor blade to obtain a rectangular green sheet that becomes the electrode layer 10 of the positive electrode.

  A pair of square grooves (recesses 10H) are formed at positions that bisect the long side of the green sheet. The pair of square grooves are provided in a straight line at intervals along the short side of the green sheet. The square groove is a through hole that passes through the front and back of the green sheet.

  Next, Ag paste (conductive fluid) is applied to the surface of the green sheet provided with the square grooves by screen printing. At that time, suction is performed from the back surface of the green sheet in the square groove, and the Ag paste is applied so as to cover the inner surface of the square groove. However, among the two square grooves, only one of the square grooves applies the Ag paste to the inner surface thereof. By applying the Ag paste, a main surface 22P that becomes the main current collecting layer is formed on the surface of the green sheet, and a connection surface 24P that becomes the connecting current collecting layer is formed on the inner side surface of the square groove.

  Next, the green sheet is divided into two divided pieces 10P at the locations where the square grooves are provided. By this division, a pair of divided pieces 10P in which the main surface 22P is formed on almost the entire surface of the green sheet and the connection surface 24P is formed on a part of one side surface is obtained.

  Next, a pair of green sheets on which the main surface 22P and the connection surface 24P are formed are joined. At that time, the orientation of the divided piece 10P is adjusted so that the main surface 22P of each green sheet faces and the connection surface 24P is adjacent.

  The pair of stacked green sheets is pressurized under the conditions of 50 ° C. and 40 MPa, and the upper and lower green sheets and the Ag paste are joined together.

  Subsequently, the bonded green sheet is heat-treated at 600 ° C. for 5 hours in an air atmosphere to remove the binder.

  Then, the green sheet after heat treatment for removing the binder is sintered under the condition of 900 ° C. × 3 h to obtain an electrode 100 (positive electrode) with a current collecting layer having a sintered electrode layer 10 (see FIG. 3A). . The thickness of each electrode layer 10 was 50 μm, the thickness of the main current collecting layer 22 was 10 μm, and the thickness of the connecting current collecting layer 24 was 20 μm.

When the electrode 100 with the current collecting layer to be the positive electrode is obtained, the solid electrolyte layer 300 is formed on the upper and lower surfaces of the electrode layer 10. Here, it was formed to a thickness 5μm a solid electrolyte layer 300 made of Li ₂ SP ₂ S ₅ by a pulsed laser deposition method.

  Further, the negative electrode 200 is formed on the surface of one solid electrolyte layer 300. Here, a negative electrode 200 made of Li metal was formed to a thickness of 20 μm by resistance heating vapor deposition. A cell is constituted by the steps up to here.

  Next, a plurality of cells produced as described above are stacked.

  And, since the current collecting layer 24 for connection is formed on the side surface of the stacked cells, that is, the side surface of the electrode 100 serving as the positive electrode, a tape-like connection is made so as to connect these current collecting layers 24 for connection. The conductor 400 is bonded to the current collecting layer 24 for connection. A copper tape was used for the connecting conductor 400, and a conductive adhesive was used for joining the connecting conductor 400 and the current collecting layer 24 for connection.

  The manufacturing method of the electrode with a current collection layer of this invention can be utilized suitably for the manufacture field of a battery. Moreover, the electrode and battery with a current collection layer of this invention can be utilized suitably as a lithium ion secondary battery etc.

100 Electrode with current collecting layer (positive electrode)
10 Electrode layer 10G Precursor 10H Recess 10P Split piece
20 Current collection layer 22 Main current collection layer 24 Current collection layer for connection 22P Main surface 24P Connection surface
200 Negative electrode
300 Solid electrolyte layer
400 connecting conductors

Claims (10)

With a current collecting layer that forms a main current collecting layer interposed between a pair of electrode layers serving as one electrode of a cell and a connecting current collecting layer for connecting the main current collecting layers of a plurality of stacked cells An electrode manufacturing method comprising:
Forming a conductive main surface on one plane of the electrode layer and a conductive connection surface on the side surface of the electrode layer so that the main surface and the connection surface are continuously connected; and
The pair of electrode layers forming the main surface and the connection surface are joined such that the main surfaces face each other and the connection surfaces are adjacent to each other, and the pair of main surfaces joined is a main current collecting layer, And a step of using a pair of adjacent connection surfaces as a current collecting layer for connection. A step of preparing a planar electrode layer;
Forming a recess in the electrode layer,
The step of forming the main surface and the connection surface includes
A process of applying a conductive fluid that becomes a main surface and a connection surface from one plane of the electrode layer to the inner surface of the recess;
Dividing the electrode layer into a plurality of divided pieces at the position of the concave portion, generating a main surface on one plane of each divided piece, and generating a connection surface on the side surface of the divided piece that was the inner side surface of the concave portion,
The step of joining the pair of electrode layers includes:
The method for producing an electrode with a current collecting layer according to claim 1, wherein the splitting pieces are joined so that the main surfaces of the pair of divided pieces face each other and the connection surfaces are adjacent to each other. In the step of forming the recess, a through hole is formed through the front and back of the electrode layer as a recess,
The method for producing an electrode with a current collecting layer according to claim 2, wherein the step of applying the conductive fluid is performed while sucking from a side opposite to the main surface of the through hole. With a current collecting layer that forms a main current collecting layer interposed between a pair of electrode layers serving as one electrode of a cell and a connecting current collecting layer for connecting the main current collecting layers of a plurality of stacked cells An electrode manufacturing method comprising:
Forming a conductive main surface on one plane of the precursor of the electrode layer, and forming a conductive connection surface on the side surface of the precursor so that the main surface and the connection surface are continuously connected; and ,
The pair of precursors forming the main surface and the connection surface are joined such that these main surfaces face each other and the connection surfaces are adjacent to each other, and the pair of main surfaces joined is a main current collecting layer, Forming a pair of adjacent connection surfaces as a current collecting layer for connection;
A method for producing an electrode with a current collecting layer, comprising the step of sintering the precursor. Preparing a planar electrode layer precursor;
Forming a recess in the precursor,
The step of forming the main surface and the connection surface includes
A process of applying a conductive fluid to be a main surface and a connection surface from one plane of the precursor to the inner surface of the recess;
Dividing the precursor into a plurality of divided pieces at the position of the concave portion, generating a main surface on one plane of each divided piece, and generating a connection surface on the side surface of the divided piece that was the inner side surface of the concave portion,
The step of joining the pair of precursors includes:
5. The method for producing an electrode with a current collecting layer according to claim 4, wherein the splitting pieces are joined so that the main surfaces of the pair of divided pieces face each other and the connection surfaces are adjacent to each other. In the step of forming the recess, a through hole is formed through the front and back of the precursor as a recess,
The method for producing an electrode with a current collecting layer according to claim 5, wherein the step of applying the conductive fluid is performed while suctioning from a side opposite to the main surface of the through hole.   The method for producing an electrode with a current collecting layer according to claim 5 or 6, wherein the step of sintering the precursor is performed after joining a pair of precursors.   The main surface and the connection surface include any metal selected from the group consisting of Ag, Cu, Ni, and Pd, or an alloy mainly including any metal. The manufacturing method of the electrode with a current collection layer of any one. A pair of electrode layers serving as one electrode of the cell; a main current collecting layer interposed between the electrode layers; and a current collecting layer for connecting the main current collecting layers of the plurality of stacked cells An electrode with a current collecting layer comprising:
The connection current collecting layer is in close contact with the side surfaces of the pair of electrode layers,
The electrode with a current collecting layer, wherein the main current collecting layer and the current collecting layer for connection are made of the same material and are continuously continuous. A battery in which a plurality of cells are stacked,
Each cell
An electrode with a current collecting layer according to claim 9,
The other electrode paired with one electrode comprising the electrode with the current collecting layer;
An electrolyte layer interposed between both electrodes,
Furthermore, the battery characterized by including the connection conductor which connects the current collection layers for connection of each cell.

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