JP2021114374A - Manufacturing method of all-solid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of manufacturing a high-performance and safe all-solid-state battery with high productivity by preventing poor pressurization of a laminated electrode body and damage to an exterior body. The method for manufacturing an all-solid-state battery disclosed herein includes a protective member forming step of forming a protective member on a side surface of a laminated electrode body. The protective member forming step includes a pressurizing step in which the flat surface 10a of the laminated electrode body 10 is sandwiched between plate-shaped molds M and pressed, and a space S formed by the side surface 10b of the laminated electrode body 10 and the mold M. It has a filling step of filling a photocurable resin or a thermosetting resin, and a curing step of forming a protective member on the side surface 10b of the laminated electrode body 10 by curing the resin material. Then, in the manufacturing method disclosed herein, protrusions M1 are formed on the side edges of the pair of plate-shaped molds M, and the space S1 facing the protrusions M1 is other than the pair of plate-shaped molds M. Is narrower than the facing space S2. [Selection diagram] Fig. 4

Description

The present invention relates to a method for manufacturing an all-solid-state battery.

In recent years, lithium ion secondary batteries, nickel-metal hydride batteries and other secondary batteries have become increasingly important as power sources for vehicles, personal computers and mobile terminals. In particular, a lithium ion secondary battery is preferably used as a high output power source for mounting on a vehicle because it is lightweight and has a high energy density. In these secondary batteries, a laminated electrode body in which a plurality of sheet-shaped electrodes are laminated can be used. Further, as a form of this kind of secondary battery, a liquid-based battery using a liquid electrolyte (electrolyte solution), a polymer battery using a gel-like electrolyte (gel electrolyte), and a solid electrolyte (solid electrolyte) are used. Examples include all-solid-state batteries. Examples of manufacturing techniques for these batteries are disclosed in Patent Documents 1 and 2.

Patent Document 1 discloses a method for manufacturing a liquid-based battery. Specifically, in the battery described in Patent Document 1, a plurality of bipolar electrodes having a positive electrode mixture layer formed on one surface of a current collector and a negative electrode mixture layer formed on the other surface are laminated. It includes an electrode laminate (laminated electrode body) and an electrolytic solution injected between adjacent bipolar electrodes. Then, in this type of liquid-based battery, a resin seal may be formed around the electrode laminate in order to prevent leakage of the electrolytic solution. Patent Document 1 discloses a method for forming such a resin seal with high accuracy.

Further, Patent Document 2 discloses a method for manufacturing a polymer battery. Specifically, the battery described in Patent Document 2 includes an electrode laminate (laminated electrode body) in which a plurality of electrode sheets are laminated with a gel electrolyte layer interposed therebetween. Then, in the manufacturing method described in Patent Document 2, the side surface of the electrode laminate is sealed with a resin-based sealing member in order to prevent the gel electrolyte layer from seeping out and causing a short circuit between the electrode sheets. There is.

JP-A-2019-133804 Japanese Unexamined Patent Publication No. 2004-193006

In addition to the liquid-based battery and the polymer battery described above, also in the all-solid-state battery, a member made of a resin material may be formed on the side surface of the laminated electrode body. Specifically, the all-solid-state battery is made of a flat-shaped laminated electrode body in which a plurality of rectangular sheet materials including an electrode sheet and a solid electrolyte layer are laminated, and a laminated film containing the laminated electrode body. It has an exterior body. Since the side surface of the laminated electrode body of this all-solid-state battery is hard and brittle, a resin protective member may be formed so as to cover the side surface. Further, such a protective member also has a function of preventing the plurality of laminated sheet materials from slipping.

Here, the solid electrolyte used in the all-solid-state battery has no fluidity unlike the electrolytic solution and the gel electrolyte. Therefore, the all-solid-state battery needs to be used in a state where a high pressure is applied to the flat surface of the laminated electrode body by using a restraining member and the electrode sheet and the solid electrolyte layer are in close contact with each other. At this time, if the pressure distribution on the flat surface of the laminated electrode body becomes non-uniform and a gap is formed between the electrode sheet and the solid electrolyte layer, a region where proper charging / discharging is not performed occurs, and the battery performance deteriorates. There is a risk of From the viewpoint of making the pressure distribution uniform during use, the protective member in the all-solid-state battery is required to have a thickness substantially equal to that of the laminated electrode body.

However, in the actual manufacturing process, burrs may be formed on the side edges of the protective member during processing. In this case, since a part of the protective member is thicker than the laminated electrode body, the pressure from the restraining member to the laminated electrode body becomes non-uniform, and the battery performance may be significantly deteriorated. Further, since the pressure is concentrated on the portion where the burr is formed, it may cause damage to the outer body made of the laminate. Therefore, in the manufacture of an all-solid-state battery, a step of inspecting whether or not burrs are formed on the protective member and a step of correcting (or discarding) the laminated electrode body in which burrs are confirmed are performed. However, in recent years, in order to improve production efficiency by omitting these steps, development of a technology that can prevent performance deterioration due to poor pressurization and damage to the exterior body due to pressure concentration even if burrs occur on the protective member. Was desired.

The present invention has been made in response to the above-mentioned requirements, and prevents poor pressurization and pressure concentration due to burrs generated on the side edges of the protective member, and produces a high-performance and safe all-solid-state battery. The main purpose is to provide a method for manufacturing an all-solid-state battery that can be manufactured by sex.

In order to solve the above problems, the present invention provides a method for manufacturing an all-solid-state battery having the following configuration (hereinafter, also simply referred to as “manufacturing method”).

The method for manufacturing an all-solid-state battery disclosed herein is a flat-shaped laminated electrode body in which a plurality of rectangular sheet materials including an electrode sheet and a solid electrolyte layer are laminated, and a laminated film accommodating the laminated electrode body. This is a method for manufacturing an all-solid-state battery including an exterior body made of a product and a protective member made of a resin formed on a side surface of a laminated electrode body. This manufacturing method includes a laminating step of laminating a plurality of sheet materials to form a laminated electrode body, a protective member forming step of forming a protective member on the side surface of the laminated electrode body, and a laminated electrode inside the exterior body. It is equipped with a containment process for accommodating the body. Further, the protective member forming step was formed by a pressurizing step of sandwiching the flat surface of the laminated electrode body with a pair of plate-shaped molds and pressurizing the flat surface, and a side surface of the laminated electrode body and a pair of plate-shaped molds. The space has a filling step of filling the space with a resin material having photocurability or thermosetting property, and a curing step of forming a protective member on the side surface of the laminated electrode body by curing the resin material. Then, in the manufacturing method disclosed herein, protrusions are formed on the side edges of the pair of plate-shaped molds, and the space facing the protrusions faces the other regions of the pair of plate-shaped molds. It's smaller than the space.

In such a manufacturing method, a plate-shaped mold having protrusions formed on the side edges is used in the protective member forming step. As a result, the space where the protrusions face each other (that is, the space where the side edges of the mold face each other) becomes narrower than the space where the other regions of the mold face each other. By filling such a space with a resin material and curing it, it is possible to form a protective member whose side edge portion is thinner than other regions. As a result, even if burrs occur on the side edges of the protective member, the restraint member and burrs do not interfere with each other when the battery is used, so that it is possible to prevent deterioration of battery performance due to poor pressurization and damage to the exterior body due to pressure concentration. .. Therefore, according to the all-solid-state battery manufacturing method disclosed herein, a high-performance and safe all-solid-state battery can be manufactured with high productivity.

It is a top view which shows typically the all-solid-state battery manufactured by the manufacturing method which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. It is a flowchart explaining the manufacturing method which concerns on one Embodiment of this invention. It is sectional drawing explaining the pressurizing process of the manufacturing method which concerns on one Embodiment of this invention. It is sectional drawing explaining the filling process of the manufacturing method which concerns on one Embodiment of this invention. It is sectional drawing explaining the curing process of the manufacturing method which concerns on one Embodiment of this invention. It is sectional drawing explaining the mold used in the manufacturing method which concerns on other embodiment of this invention. It is sectional drawing explaining the filling process of the manufacturing method which concerns on other embodiment of this invention.

Hereinafter, a method for manufacturing an all-solid-state battery according to an embodiment of the present invention will be described with reference to the drawings. In addition, matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention (for example, manufacturing of electrode bodies, electrode terminals, etc.) are those skilled in the art based on the prior art in the art. It can be grasped as a design matter of. In each of the figures shown in the present specification, members / parts having the same action are described with the same reference numerals. Further, the dimensional relations (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relations.

1. 1. Structure of all-solid-state battery The manufacturing method according to the present embodiment is a method for manufacturing an all-solid-state battery. In this specification, first, the structure of the all-solid-state battery to be manufactured will be described. FIG. 1 is a plan view schematically showing an all-solid-state battery manufactured by the manufacturing method according to the present embodiment. Further, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. In each figure, reference numeral X indicates "width direction", reference numeral Y indicates "depth direction", and reference numeral Z indicates "height direction". These directions are defined for convenience of explanation and are not intended to limit the techniques disclosed herein.

As shown in FIGS. 1 and 2, the all-solid-state battery 1 is a flat-shaped laminated battery. Although not shown, the all-solid-state battery 1 is used in a state of being pressurized so as to sandwich the flat surface 1a by a restraining member. The all-solid-state battery 1 includes a laminated electrode body 10, an exterior body 20, and a protective member 40. Hereinafter, each structure will be described.

(1) Laminated Electrode Body As shown in FIG. 1, the laminated electrode body 10 is a flat electrode body. Specifically, as shown in FIG. 2, a flat laminated electrode body 10 is formed by laminating a plurality of rectangular sheet materials 16 including an electrode sheet 12 and a solid electrolyte layer 14 in the height direction Z. Will be done. The detailed structure and material of each of the sheet materials 16 are not particularly limited, and the sheet materials conventionally used in this type of secondary battery can be used without particular limitation.

For example, as the electrode sheet 12, two types of electrode sheets including a positive electrode sheet and a negative electrode sheet can be used. The positive electrode sheet includes a positive electrode current collector and a positive electrode mixture layer formed on the surface (both sides) of the positive electrode current collector. Further, the positive electrode mixture layer is not formed at one end of the positive electrode sheet in the width direction X, and the positive electrode exposed portion where the positive electrode current collector is exposed is formed. The positive electrode current collector is a foil-shaped conductive member (aluminum foil or the like). The positive electrode mixture layer is a layer containing a positive electrode active material. The positive electrode active material is a material capable of reversibly storing and releasing charge carriers (for example, lithium ions). As the positive electrode active material, a material that can be used for this type of secondary battery can be used without particular limitation. As an example of such a positive electrode active material, a lithium transition metal such as a lithium nickel-containing composite oxide, a lithium cobalt-containing composite oxide, a lithium nickel cobalt-containing composite oxide, a lithium manganese-containing composite oxide, and a lithium nickel cobalt manganese-containing composite oxide. Composite oxides can be mentioned. The positive electrode mixture layer may contain additives other than the positive electrode active material (for example, a binder, a conductive material, a solid electrolyte material, etc.).

On the other hand, the negative electrode sheet includes a negative electrode current collector and a negative electrode mixture layer formed on the surface (both sides) of the negative electrode current collector. The negative electrode current collector is a foil-shaped conductive member (copper foil or the like). Further, the negative electrode mixture layer is not formed at one end of the negative electrode sheet in the width direction X, and the negative electrode exposed portion where the negative electrode current collector is exposed is formed. The negative electrode mixture layer contains at least the negative electrode active material. The negative electrode active material is a material capable of reversibly storing and releasing charge carriers (for example, lithium ions). As the negative electrode active material, a material that can be used for this type of secondary battery can be used without particular limitation. Examples of such a negative electrode active material include carbon materials such as hard carbon, graphite, and boron-added carbon. The negative electrode mixture layer may contain an additive (for example, a binder, a solid electrolyte material, etc.) other than the negative electrode active material, if necessary.

The solid electrolyte layer 14 is arranged between the electrode sheets 12 (typically, the positive electrode sheet and the negative electrode sheet). The solid electrolyte layer is composed of a powdery electrolyte (solid electrolyte material) having Li ion conductivity and insulating properties. Although not particularly limited, a sulfide solid electrolyte material, an oxide solid electrolyte material, or the like can be used as the solid electrolyte material. The sulfide solid electrolyte, for _example, Li ₂ S-SiS 2 _{system, Li 2 S-P 2 S} 3 _{system, Li 2 S-P 2 S} 5 _based, Li ₂ S-GeS 2 system, _Li 2 S-B Examples thereof include glass or glass ceramics such as ₂ S ₃ series, Li ₃ PO _4- P ₂ S ₅ series, Li ₄ SiO _{4- Li 2} S-SiS _{2 series.} On the other hand, examples of the oxide solid electrolyte material include lithium lanthanum zirconium-containing composite oxide (LLZO), Al-doped-LLZO, lithium lanthanum titanium-containing composite oxide (LLTO), Al-doped-LLTO, and lithium oxynitride phosphate. (LIPON) and the like. The solid electrolyte layer 14 may contain an additive (for example, a binder or the like) other than the solid electrolyte material.

Further, as shown in FIG. 1, a positive electrode connecting portion 10A in which only the exposed positive electrode portion is laminated is formed at one end portion of the width direction X of the laminated electrode body 10, and the other end portion is formed. Is formed with a negative electrode connecting portion 10B in which only the exposed negative electrode portion is laminated. Further, in the central portion of the laminated electrode body 10 in the width direction X, a core portion 10C in which the positive electrode mixture layer, the negative electrode mixture layer, and the solid electrolyte layer 14 are laminated so as to face each other is formed. Then, the positive electrode terminal 32 is connected to the positive electrode connecting portion 10A, and the negative electrode terminal 34 is connected to the negative electrode connecting portion 10B. The positive electrode terminal 32 and the negative electrode terminal 34 are plate-shaped conductive members extending along the width direction X. One end of the positive electrode terminal 32 and the negative electrode terminal 34 is connected to the laminated electrode body 10, and the other end is exposed to the outside of the exterior body 20. In the following description, of the outer peripheral surfaces of the laminated electrode body 10, the surface on the side to which the positive electrode terminal 32 is connected is referred to as “front”, and the surface on the side to which the negative electrode terminal 34 is connected is referred to as “back surface”. .. The outer peripheral surface to which the positive electrode terminal 32 and the negative electrode terminal 34 are not connected is referred to as a "side surface".

(2) Exterior body The exterior body 20 is a container made of a laminated film that houses the laminated electrode body 10. Specifically, the exterior body 20 is composed of a pair of exterior films 22 and 24 that face each other with the laminated electrode body 10 interposed therebetween (see FIG. 2). These exterior films 22 and 24 include a resin layer made of an insulating resin (for example, polypropylene). Then, by welding the resin layers to each other at the outer peripheral edges of the facing exterior films 22 and 24, a bag-shaped exterior body 20 accommodating the laminated electrode body 10 is formed. The exterior films 22 and 24 may be films having a multilayer structure having a layer other than the resin layer. As an example, the high-strength exterior body 20 can be formed by forming a metal layer made of a metal material such as aluminum on the outside of the resin layer.

(3) Protective member The protective member 40 is a resin member formed on the side surface 10b of the laminated electrode body 10. Specifically, as shown in FIG. 1, the protective member 40 extends along the width direction X so as to cover both side surfaces of the core portion 10C of the laminated electrode body 10. By forming the protective member 40 on the side surface 10b of the laminated electrode body 10, it is possible to prevent the side edges of the sheet material 16 (electrode sheet 12, solid electrolyte layer 14, etc.) from being damaged by an external impact or the like. .. Further, although detailed description is omitted in FIG. 2, the protective member 40 includes a side edge portion of a part of the sheet material 16 among the plurality of sheet material 16. As a result, the sheet material 16 constituting the laminated electrode body 10 can be fixed, and deterioration of battery performance due to displacement of the sheet material 16 can be prevented. The protective member 40 is formed by curing a resin material having photocurability or thermosetting property. The resin material that is the precursor of the protective member 40 will be described in detail later.

Then, in the all-solid-state battery 1 manufactured by the manufacturing method according to the present embodiment, the chamfered portion 42 is formed on the side edge portion of the protective member 40. The side edge portion of the protective member 40 on which the chamfered portion 42 is formed is thinner (dimension along the height direction Z) than the other region of the protective member 40. As a result, when the flat surface 1a of the all-solid-state battery 1 is pressurized with the restraint jig, the restraint jig does not come into contact with the side edge portion of the protective member 40, so that burrs are generated on the side edge portion of the protective member 40. Even so, the burr and the pressurizing jig do not interfere with each other. As a result, it is possible to prevent deterioration of battery performance due to poor pressurization and damage to the exterior body 20 due to pressure concentration. Hereinafter, a method of manufacturing the all-solid-state battery 1 in which the protective member 40 having such a chamfered portion 42 is formed will be described.

2. Manufacturing Method of All-Solid State Battery FIG. 3 is a flowchart illustrating a manufacturing method according to the present embodiment. As shown in FIG. 3, the method for manufacturing an all-solid-state battery according to the present embodiment includes a laminating step S10, a protective member forming step S20, and a housing step S30. The protective member forming step S20 includes a pressurizing step S22, a filling step S24, and a curing step S26. Hereinafter, each step will be described.

(1) Laminating step S10
In the laminating step S10, a plurality of rectangular sheet materials are laminated to form a flat laminated electrode body. Specifically, the electrode sheet 12 and the solid electrolyte layer 14 are alternately laminated so that the positive electrode and the negative electrode face each other with the solid electrolyte layer 14 interposed therebetween (see FIG. 2). As a result, the laminated electrode body 10 in which a plurality of sheet materials 16 are laminated is formed. The number of sheets 16 to be laminated is not particularly limited, and a laminated electrode body 10 that functions appropriately as an electrode body can be formed by laminating one positive electrode sheet, one solid electrolyte layer, and one negative electrode sheet. However, in consideration of the structural stability of the laminated electrode body 10, the battery performance, and the like, the number of sheets 16 to be laminated is preferably 2 or more, more preferably 10 or more, further preferably 20 or more, and 30 or more. The above is particularly preferable.

In addition, in FIG. 2 and FIGS. 4 to 6, the side surfaces of the respective sheet materials 16 are aligned so that the side surface 10b of the laminated electrode body 10 is substantially flat. However, the laminating process is not limited to such a form. For example, each sheet material 16 may be laminated so that the solid electrolyte layer 14 projects from the side surface of the electrode sheet 12. As a result, it is possible to prevent the electrode sheets 12 from coming into contact with each other and short-circuiting at the side edge portion of the laminated electrode body 10.

(2) Protective member forming step S20
The protective member forming step is a step of forming the protective member 40 on the side surface 10b of the laminated electrode body 10. As described above, the protective member forming step S20 of the manufacturing method according to the present embodiment includes a pressurizing step S22, a filling step S24, and a curing step S26. Hereinafter, each step carried out in the protective member forming step S20 will be described.

(A) Pressurizing step S22
FIG. 4 is a cross-sectional view illustrating a pressurizing step of the manufacturing method according to the present embodiment. As shown in FIG. 4, in this step, the flat surface 10a of the laminated electrode body 10 is sandwiched between a pair of plate-shaped molds M and pressurized. As a result, the laminated electrode body 10 is compressed along the height direction Z, and each of the plurality of sheet materials 16 is brought into close contact with each other. The pressure applied to the flat surface 10a of the laminated electrode body 10 is preferably 0.1 MPa or more, more preferably 1 MPa or more, still more preferably 5 MPa or more. As the pressure on the laminated electrode body 10 is increased, the adhesion between the sheet materials 16 tends to improve. On the other hand, if the pressure is increased too much, the sheet material 16 and the mold M may be damaged. From this point of view, the pressure on the laminated electrode body 10 is preferably 100 MPa or less, more preferably 50 MPa or less, still more preferably 20 MPa or less.

The pressurizing device used in this step may include a pair of plate-shaped molds M as shown in FIG. 4, and the detailed structure is not particularly limited. For example, the pressurizing device is based on the measurement results of, in addition to the pair of molds M, a power device for moving the molds M closer to and apart from each other, a pressure gauge for measuring the pressure on the laminated electrode body 10, and a pressure gauge. It is preferable to have a control unit for controlling the power unit. By using the pressure device having such a configuration, the pressure on the laminated electrode body 10 can be controlled to a suitable state.

Further, as the mold M, a material having a strength capable of withstanding the above-mentioned pressure can be used without particular limitation. The material of the mold M is preferably selected as appropriate according to the type of the resin material 140 used in the filling step S24 described later. For example, when a photocurable resin is used as the resin material 140, it is preferable to use a light-transmitting material for the mold M. Examples of such a material include a fluorinated resin such as polytetrafluoroethylene (PTFE) (trade name: Teflon (registered trademark), manufactured by DuPont), polypropylene (PP), and the like. When a thermosetting resin is used as the resin material 140, it is preferable to use a material having high heat resistance and excellent thermal conductivity for the mold M. Examples of such a material include metal materials such as iron and stainless steel. Considering the releasability of the resin material 140 after curing, when a metal material is used, it is preferable that the facing surface of the mold M is fluorinated.

Here, the dimension of the mold M in the depth direction Y is set to be longer than the dimension of the laminated electrode body 10 in the depth direction Y. Therefore, when the pressurizing step S22 is carried out, a space S surrounded by the side surface 10b of the laminated electrode body 10 and the pair of molds M is generated outside the side surface 10b of the laminated electrode body 10. A protrusion M1 is formed on each side edge of the mold M used in the present embodiment. Therefore, the space S1 facing the protrusion M1 (that is, the side edge portion of the mold M) is narrower than the space S2 facing the other region of the mold M.

Further, in the present embodiment, a protrusion M1 having an inclined surface inclined at a predetermined inclination angle θ is formed so that the space S1 becomes narrower toward the outside of the depth direction Y (upper side in FIG. 4). By forming the protrusion M1 having such an inclined surface, it is possible to prevent the exterior body 20 from being damaged at the portion where the chamfered portion 42 and the exterior body 20 come into contact with each other (see FIG. 2). The inclination angle θ of the protrusion M1 is preferably 45 ° or less, more preferably 30 ° or less. Thereby, the filling property of the resin material 140 to the starting point M1a of the protrusion M1 and the releasability after curing can be improved. Further, when the thickness of the laminated electrode body 10 in the pressurized state is "t", the maximum dimension a of the protrusion M1 in the height direction Z is set within the range of 0 <2a <t. However, the maximum dimension a of the protrusion M1 is preferably 0.15 mm or more from the viewpoint of forming the chamfered portion 42 on the protective member 40 which can appropriately prevent uneven pressure distribution and damage to the exterior body during use. 0.2 mm or more is more preferable, and 0.25 mm or more is further preferable. Further, the dimension c of the protrusion M1 in the depth direction Y is appropriately adjusted within a range in which the protrusion M1 does not interfere with the laminated electrode body 10, and is determined by the inclination angle θ of the protrusion M1 and the maximum dimension a of the protrusion M1 in the height direction Z. It is determined (a = c · tan θ).

(B) Filling Process FIG. 5 is a cross-sectional view illustrating a filling process of the manufacturing method according to the present embodiment. As shown in FIG. 5, in the filling step S24, the resin material 140 is filled in the space S (see FIG. 4) formed by the side surface 10b of the laminated electrode body 10 and the pair of plate-shaped molds M. A photocurable resin or a thermosetting resin is used as the resin material 140 to be filled in this step. The photocurable resin may be any resin material that is cured by causing a polymerization reaction, a cross-linking reaction, or the like by light irradiation, and conventionally known photocurable resins can be used without particular limitation. Examples of such a photocurable resin include urethane acrylate, polyester acrylate, oxetane resin, silicone resin and the like. On the other hand, the thermosetting resin may be any resin material that is cured by heat, and conventionally known thermosetting resins can be used without particular limitation. The thermosetting resin is preferably a resin material that cures at a temperature equal to or lower than the heat resistant temperature of the laminated electrode body 10. Examples of such thermosetting resins include phenol resins, epoxy resins, silicone resins, polyurethane resins, urea resins and the like.

Further, in this step, if a large amount of the resin material 140 permeates between the sheet materials 16, the performance of the all-solid-state battery 1 after production may deteriorate. From this point of view, the viscosity of the resin material 140 is preferably 5000 Pa · s or more, more preferably 7500 Pa · s or more, further preferably 10000 Pa · s or more, and particularly preferably 12500 Pa · s or more. On the other hand, if the viscosity of the resin material 140 is too high, the resin material 140 may not be properly filled in the space S, and the protective member may be poorly formed. From this point of view, the upper limit of the viscosity of the resin material 140 is preferably 50,000 Pa · s or less, more preferably 45,000 Pa · s or less, further preferably 40,000 Pa · s or less, and particularly preferably 30,000 Pa · s or less.

The method of filling the space S with the resin material 140 is not particularly limited, and conventionally known methods can be used without limitation. However, as shown in FIG. 1, the protective member 40 is formed so as to cover the side surface of the core portion 10C of the laminated electrode body 10, and is not formed on the side surface of the positive electrode connecting portion 10A or the negative electrode connecting portion 10B. preferable. In this way, in order to fill the side surface of the core portion 10C of the laminated electrode body 10 with the resin material 140 with high accuracy, the laminated electrode body 10 is moved along the width direction (direction perpendicular to the paper surface of FIG. 5). However, it is preferable to use a nozzle that discharges the resin material 140 and fill the space S with the resin material while controlling the movement amount and the movement speed of the nozzle. Further, the laminated electrode body 10 may be compressed while the resin material 140 is being filled, and the pressure from the mold M may fluctuate. At this time, in order to prevent the resin material 140 from penetrating between the sheet materials 16, it is preferable to fill the resin material 140 while controlling the mold M so that the pressure is kept constant.

Further, as shown in FIG. 5, in this step, the resin material 140 may overflow from the space S to generate a surplus resin 140a. In this case, it is preferable to remove the excess resin 140a by scraping the side surface M2 of the mold M with a scraper (resin removing step). In general, when the excess resin is removed by a scraper, burrs are likely to occur on the side edges of the protective member. However, in the present embodiment, even if burrs are generated on the side edges of the protective member, various problems due to the interference of the burrs can be suitably prevented. In the manufacturing method disclosed here, the step of removing the excess resin is not essential. For example, a liquid level detection sensor may be provided in the nozzle for injecting the resin material, and the filling amount of the resin material may be controlled so that excess resin is not generated. Further, the portion where the surplus resin 140a is cured may be removed from the protective member 40 after the curing step S26 described later is performed.

(C) Curing Step FIG. 6 is a cross-sectional view illustrating a curing step of the manufacturing method according to the present embodiment. As shown in FIG. 6, in the curing step S26, the protective member 40 is formed on the side surface 10b of the laminated electrode body 10 by curing the resin material 140 (see FIG. 5) filled in the space S. In this step, means corresponding to the type of the resin material 140 filled in the filling step S24 are appropriately adopted. For example, when a photocurable resin is used as the resin material 140, the protective member 40 is formed by irradiating with ultraviolet rays or the like. On the other hand, when a thermosetting resin is used as the resin material 140, the protective member 40 is formed by heating the resin material 140. The conditions relating to the curing (light irradiation, heating) of the resin material 140 can be appropriately adjusted according to the type of the resin material 140, and the techniques disclosed herein are not limited, so detailed description thereof will be omitted.

Then, after the resin material 140 is cured, the pair of molds M are separated from each other and the laminated electrode body 10 is taken out. As a result, the laminated electrode body 10 in which the resin protective member 40 is formed on the side surface 10b is obtained.

(3) Containment Step Next, in the accommodating step S30, as shown in FIGS. 1 and 2, the laminated electrode body 10 on which the protective member 40 is formed is accommodated inside the exterior body 20. Specifically, the laminated electrode body 10 is sandwiched between a pair of exterior films 22 and 24, and the outer peripheral edges of the exterior films 22 and 24 are heated while being pressurized. As a result, the outer peripheral edges of the exterior films 22 and 24 are welded, and the all-solid-state battery 1 in which the laminated electrode body 10 is housed inside the exterior body 20 is manufactured.

In the all-solid-state battery 1 manufactured in this manner, a chamfered portion 42 is formed on the side edge portion of the protective member 40. Therefore, the thickness of the side edge portion of the protective member 40 becomes thinner than the other regions of the protective member 40, and when the flat surface 1a of the all-solid-state battery 1 is pressed by the restraint member, the side edge portion of the protective member 40 is formed. The restraint members do not come into contact. As a result, even if burrs occur on the side edges of the protective member 40, it is possible to prevent deterioration of battery performance due to poor pressurization and damage to the exterior body 20 due to pressure concentration. Therefore, in the manufacturing method according to the present embodiment, it is not necessary to provide a step of inspecting the presence or absence of burrs or a step of correcting burrs between the protective member forming step S20 and the accommodating step S30, and the performance is high and safe. All-solid-state batteries can be manufactured with high productivity.

3. 3. Other Embodiments The manufacturing method according to one embodiment of the present invention has been described above. It should be noted that the techniques disclosed herein are not limited to the above-described embodiments, but include other embodiments with various modifications. Hereinafter, other embodiments of the present invention will be described. FIG. 7 is a cross-sectional view illustrating a mold used in the manufacturing method according to another embodiment. Further, FIG. 8 is a cross-sectional view illustrating a filling step of the manufacturing method according to another embodiment.

For example, as shown in FIGS. 4 to 6, in the manufacturing method according to the above-described embodiment, a mold M having a protrusion M1 having an inclined surface inclined at a predetermined inclination angle θ is used. However, the protrusion may be formed on the side edge of the mold, and its shape is not limited to the above-described embodiment.

As an example, as shown in FIG. 7, a chamfered portion M1b may be formed at the tip of a protrusion M1 of the mold M. As a result, it is possible to prevent the tip of the protrusion M1 from being deformed or chipped. When the mold M as shown in FIG. 7 is used, a convex portion 41 projecting in the height direction Z is formed on the side edge portion of the protective member 40. From the viewpoint of preventing the convex portion 41 from causing non-uniform pressure and damage to the exterior body, the dimension b of the chamfered portion M1b in the height direction Z is the dimension a of the protrusion M1 in the height direction Z (FIG. It is preferable to make it shorter than 4). As an example, the dimension b of the chamfered portion M1b is preferably 0.1 mm or more shorter than the dimension a of the protrusion M1 in the height direction Z. Further, from the viewpoint of preferably preventing deformation and chipping of the tip of the protrusion M1, the chamfering dimension b is preferably 0.05 mm or more.

Further, as another example, as shown in FIG. 8, a curved protrusion M1 may be formed on the side edge portion of the mold M. In such a case, since the surface of the chamfered portion 42 of the protective member 40 has an arc shape, damage to the exterior body due to interference with the protective member 40 can be suitably prevented. From the viewpoint of more preferably preventing damage to the exterior body, the radius of curvature of the curved protrusion M1 is preferably 0.1 mm or more, more preferably 0.2 mm or more, further preferably 0.25 mm or more, and 0. 5 mm or more is particularly preferable.

Further, in the above-described embodiment, two types of electrode sheets including a positive electrode sheet and a negative electrode sheet are used as the electrode sheet 12. However, the electrode sheet is not limited to this, and a bipolar electrode can also be used. A bipolar electrode is an electrode in which a positive electrode mixture layer is formed on one surface of a current collector and a negative electrode mixture layer is formed on the other surface. A predetermined metal material (Al, Fe, Ti, Ni, Zn, Cr, Au, Pt, etc.) is used for the current collector of the bipolar electrode. Further, since the same material as the positive electrode mixture layer of the positive electrode sheet described above can be used for the positive electrode mixture layer of the bipolar electrode, detailed description thereof will be omitted. Similarly, for the negative electrode mixture layer of the bipolar electrode, the same material as the negative electrode mixture layer of the negative electrode sheet described above can be used.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

1 All-solid-state battery 10 Laminated electrode body 10A Positive electrode connection part 10B Negative electrode connection part 10C Core part 12 Electrode sheet 14 Solid electrolyte layer 16 Sheet material 20 Exterior body 22, 24 Exterior film 32 Positive electrode terminal 34 Negative electrode terminal 40 Protective member 41 Convex part 42 Chamfered portion 140 Resin material 140a Surplus resin M Mold M1 Protrusion S Space S10 Laminating step S20 Protective member forming step S22 Pressurizing step S24 Filling step S26 Hardening step S30 Containment step X Width direction Y Depth direction Z Height direction θ Tilt angle

Claims (1)

A flat laminated electrode body in which a plurality of rectangular sheet materials including an electrode sheet and a solid electrolyte layer are laminated, an outer body made of a laminated film accommodating the laminated electrode body, and the laminated electrode body. It is a method of manufacturing an all-solid-state battery provided with a resin protective member formed on a side surface.
A laminating step of laminating a plurality of the sheet materials to form the laminated electrode body, and
A protective member forming step of forming the protective member on the side surface of the laminated electrode body, and
A housing step for housing the laminated electrode body is provided inside the exterior body.
The protective member forming step is
A pressurizing step in which the flat surface of the laminated electrode body is sandwiched between a pair of plate-shaped molds and pressurized.
A filling step of filling a space formed by the side surface of the laminated electrode body and the pair of plate-shaped molds with a resin material having photocurability or thermosetting.
A curing step of forming the protective member on the side surface of the laminated electrode body by curing the resin material, and
Have and
A protrusion is formed on the side edge portion of the pair of plate-shaped molds, and the space facing the protrusions is narrower than the space facing the other regions of the pair of plate-shaped molds. A method of manufacturing an all-solid-state battery.

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