JP2020004528A - Manufacturing method of all-solid battery - Google Patents

Abstract

To provide a manufacturing method of all-solid battery capable of restraining dimensional variation of a resin layer formed on the lateral face of a battery laminate, while covering up to the gap between extension parts reliably with the resin layer.SOLUTION: A manufacturing method of all-solid battery includes following steps: (a) to prepare a battery laminate including more than one unit cell, having an extension part extending farther outside than other layers, on the lateral face of the battery laminate, with a gap formed between the extension parts; (b) to fill the gap with a first resin by capillary underfill method using pressure reduction, and to form a first resin layer by hardening the first resin; and (c) to cover the lateral face of the first resin layer and the lateral face of the battery laminate with second resin, by injection molding, transfer molding, or dipping molding, and to form a second resin layer by hardening the second resin.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a method for manufacturing an all-solid-state battery. In particular, the present disclosure relates to a method for manufacturing an all-solid battery having a battery stack and a resin layer covering the battery stack.

  The all-solid-state battery includes a battery stack including at least one unit battery in which a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are stacked in this order. Have. Further, in the battery stack, generally, at least one of the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer is more than other layers. It has an extending portion extending outward, and a gap is formed between the extending portions on the side surface of the battery stack.

  Various techniques have been developed to ensure that the resin is embedded up to the gap when the side face of the battery stack having such a gap on the side face is covered with a resin layer.

  For example, in Patent Literature 1, a capillary underfill method, in particular, a capillary underfill method using reduced pressure, is applied to a side of a battery stack in which a gap is formed between extending portions. A method for manufacturing an all-solid battery in which is coated with a resin layer is disclosed.

  More specifically, a method of covering the gap between the extending portions and the entire side surface of the battery stack with a resin layer by a capillary underfill method using reduced pressure is as follows, for example. That is, first, a battery stack in which a gap is formed between the extending portions is prepared. Then, a liquid resin is supplied to the side surface of the battery stack under a reduced pressure atmosphere. Thereafter, the reduced pressure is released, and the liquid resin adheres to the gap and the entire side surface of the battery stack by the capillary action and the differential pressure. Finally, by curing the liquid resin adhering to the side surfaces of the battery stack, manufacturing a solid-state battery in which the gaps between the extending portions and the entire side surfaces of the battery stack are covered with the resin layer. Can be.

JP 2017-22047 A

  As described above, when manufacturing an all-solid-state battery in which the gap between the extending portions and the entire side surface of the battery stack is covered with the resin layer by utilizing the capillary underfill method using reduced pressure, it is necessary to perform reduced pressure. There is. This decompression and the subsequent release of the decompression are steps necessary to allow the resin to enter the gap between the extending portions, but may cause variations in the dimensions of the resin layer formed on the side surface of the battery stack. is there.

  Therefore, the present disclosure has been made in view of the above circumstances, and suppresses variation in the size of the resin layer formed on the side surface of the battery stack while reliably covering the gap between the extension portions with the resin layer. It is an object of the present invention to provide a method of manufacturing an all-solid-state battery capable of performing the following.

The present inventors of the present disclosure have found that the above object can be achieved by a method for manufacturing an all-solid battery including the following steps:
(A) Prepare a battery laminate including two or more unit batteries in which a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are laminated in this order. Wherein, at least one of the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer is a side surface of the battery stack. Has an extending portion extending outward from other layers, and a gap is formed between the extending portions;
(B) filling the gap with a first resin by a capillary underfill method using reduced pressure, and curing the first resin to form a first resin layer; and (c) injection molding The side surface of the first resin layer and the side surface of the battery laminate are covered with a second resin by a method, a transfer molding method, or a dipping molding method, and the second resin is cured to form a second resin. Forming a layer.

  ADVANTAGE OF THE INVENTION According to the manufacturing method of the all-solid-state battery of this indication, the dispersion | variation in the dimension of the resin layer formed in the side surface of a battery laminated body can be suppressed, ensuring the gap between extension parts with a resin layer. .

FIG. 1 is an explanatory diagram illustrating one embodiment of the method of the present disclosure. FIG. 2 is a schematic cross-sectional view illustrating an example of an all-solid-state battery obtained by the method of the present disclosure.

  Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. Note that, for convenience of description, the same or corresponding portions are denoted by the same reference numerals in each drawing, and redundant description will be omitted. All of the components of the embodiment are not necessarily essential, and some components may be omitted in some cases. However, the embodiments shown in the following drawings are examples of the present disclosure, and do not limit the present disclosure.

製造 Manufacturing method of all solid state battery≫
The method for manufacturing an all solid state battery of the present disclosure includes the following steps:
(A) Prepare a battery laminate including two or more unit batteries in which a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are laminated in this order. That, here, at least one layer of the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer is on the side surface of the battery stack more than other layers. Also have outwardly extending extensions, and gaps are formed between the extensions.
(B) filling a gap with a first resin by a capillary underfill method using reduced pressure, and curing the first resin to form a first resin layer; and (c) an injection molding method A second resin layer is formed by covering the side surface of the first resin layer and the side surface of the battery stack with a second resin by a transfer molding method or a dipping molding method, and curing the second resin. thing.

  Hereinafter, each step according to the present disclosure will be described in detail.

<Step (a)>
In the step (a), a battery stack including two or more unit batteries in which a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are laminated in this order Prepare Here, at least one of the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer is more outer than the other layers on the side surface of the battery stack. And a gap is formed between the extending portions.

  FIG. 1A shows one embodiment of the step (a) according to the present invention. More specifically, in FIG. 1A, a monopolar battery stack 20 including 11 unit batteries 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6j, 6k, and 6l is prepared. The illustrated embodiment is shown.

  Each of these unit batteries 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6j, 6k, and 6l has a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, And a negative electrode current collector layer in this order, and on the side surface of the battery stack 20, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are formed of a positive electrode current collector layer and a positive electrode current collector layer. It has extensions that extend outward from the active material layer, and gaps X1, X2, X3, X4, and X5 are formed between the extensions.

<Step (b)>
In the step (b), the gap is filled with a first resin by a capillary underfill method using reduced pressure, and the first resin is cured to form a first resin layer.

  In the present disclosure, the form of the first resin is not particularly limited, but is generally preferably a liquid resin from the viewpoint of application to a capillary underfill method using reduced pressure. The liquid does not necessarily need to be liquid at room temperature, and may be a resin that is melted by heating.

  Further, the type of the first resin is not particularly limited, and may be a curable resin or a thermoplastic resin. Further, the curable resin may be a thermosetting resin, a photocurable resin (for example, a UV curable resin), or an electron beam curable resin. That is, it may be an epoxy resin, an amine resin, an acrylic resin, a polyimide resin, a polyester resin, a polypropylene resin, a polyamide resin, a polystyrene resin, a polyvinyl chloride resin, or a polycarbonate resin, but is not limited thereto.

  More specifically, the first resin is preferably the same as the underfill resin in the field of semiconductor manufacturing. For example, as the first resin, an epoxy resin or an amine resin is preferably used.

  The viscosity of the first resin when filling the gap on the side surface of the battery stack with the first resin may be 1000 mPa · s or more, preferably 2000 mPa · s or more, and preferably 3000 mPa · s. More preferably, it may be 3500 mPa · s or less. According to such a viscosity, the first resin can be more easily filled into the gap on the side surface of the battery stack by the capillary action and the differential pressure.

  The “capillary underfill method using reduced pressure” referred to in the present disclosure specifically refers to the following method.

  That is, first, the pressure of the prepared battery stack is reduced. This makes it possible to remove air, moisture, and the like in gaps on the side surfaces of the battery stack, or air, moisture, and the like existing inside the battery stack. Next, while maintaining the reduced-pressure atmosphere, the liquid resin is supplied to the gap between the extending portions with respect to the side surface of the battery stack. Thereafter, the reduced pressure is released or pressurized. Thereby, the gap between the extending portions of the battery stack can be more efficiently filled with the liquid resin.

  In the present disclosure, the degree of pressure reduction during pressure reduction is not particularly limited. For example, it is preferable to reduce the pressure until the atmospheric pressure becomes 1000 Pa or less, 500 Pa or less, or 130 Pa or less.

  The release of the reduced pressure is to control the pressure to be higher than the atmospheric pressure when the first resin is supplied to the gap between the extending portions, and the atmospheric pressure may be released to the atmospheric pressure. At this time, the pressure may be increased to a pressure higher than the atmospheric pressure.

  The pressure reduction is not particularly limited, and can be achieved, for example, by installing the battery stack in a chamber and then evacuating the chamber.

  The filling rate and the filling amount of the first resin with respect to the gap on the side surface of the battery stack may be appropriately adjusted depending on the form of the gap on the side surface of the battery stack, and the amount overflows from each gap to a portion other than the gap. The amount may not be too small or may be an amount that at least partially covers portions other than the gaps, but is preferably an amount that does not overflow from the gaps to portions other than the gaps.

  Means for filling the first resin is not particularly limited. For example, in a state where the battery stack is installed in the chamber, a dispense nozzle is installed at a location near the side surface of the battery stack, and It can function as a means for filling the first resin. More specifically, the dispense nozzle can be connected to a first resin supply source provided outside the chamber, and supplied from the first resin supply source to the dispense nozzle via a pipe. By discharging the first resin from the tip of the dispensing nozzle, the gap on the side surface of the battery stack can be filled with the first resin. Further, only one means for filling the first resin may be provided in the chamber, or a plurality of means may be provided in the chamber. Further, it is preferable that the means for filling the first resin is movable around the side surface of the battery stack.

  The method of curing the first resin can be appropriately performed according to the type of the resin used. For example, when a thermosetting resin is used as the first resin, the first resin can be cured by filling the gap with the first resin and then heating at least the side surface of the battery stack. . When an ultraviolet curable resin is used as the first resin, the first resin is cured by filling the gap with the first resin and then irradiating at least the side surface of the battery stack with ultraviolet light. be able to. When a thermoplastic resin is used as the first resin, the gap is filled with the first resin, and then at least the side surface of the battery stack is cooled (including natural cooling), whereby the first resin is cooled. Can be cured.

  The filling and / or curing of the first resin is preferably performed at a low dew point. For example, it is preferable to perform at a low dew point of -30 ° C or lower or -50 ° C or lower. In addition, when the atmosphere pressure described later includes control means, the first resin can be filled and / or cured under a low dew point by setting the atmosphere to a dry air atmosphere.

  FIG. 1B illustrates an embodiment after performing the step (b) according to the present disclosure. That is, an aspect in which the first resin layer 21 is formed in the gaps X1, X2, X3, X4, and X5 between the extending portions is shown.

<Step c>
In the step (c), the side surface of the first resin layer and the side surface of the battery stack are covered with the second resin by an injection molding method, a transfer molding method, or a dipping molding method, and the second resin is cured. Then, a second resin layer is formed.

  In the present disclosure, the form of the second resin is not particularly limited, and is preferably a liquid resin. The liquid does not necessarily have to be liquid at room temperature, and may be a resin that is melted by heating.

  In addition, the type of the second resin is not particularly limited, and reference should be appropriately made to those listed as the types of the first resin described above.

  In the present disclosure, the second resin and the first resin may be of different types or may be of the same type at the same time.

  The method of curing the second resin can be appropriately performed according to the type of the resin to be used, and the description of the method of curing the first resin described above can be appropriately referred to.

(Injection molding method)
When using an injection molding method, for example, a battery laminate having a first resin layer is set in a mold, and a liquid second resin is injected into the mold to form a first resin layer. The side surface and the side surface of the battery stack are covered with the second resin. Thereafter, the second resin layer can be formed by curing the second resin.

(Transfer molding method)
When the transfer molding method is used, for example, a battery laminate having a first resin layer is set in a mold, and a liquid second resin is injected from a plunger (transfer chamber) into the mold. The side surface of the first resin layer and the side surface of the battery stack are covered with a second resin. After that, the second resin layer is formed by curing the second resin.

(Dipping molding method)
When the dipping molding method is used, for example, after injecting a liquid second resin into a mold, a battery laminate having a first resin layer is immersed in a second resin solution in the mold, and The laminate is pulled up, and the side surface of the first resin layer and the side surface of the battery laminate are covered with the second resin. After that, the second resin layer can be formed by curing the second resin.

  As described above, the mold is used in any of the injection molding method, the transfer molding method, and the dipping molding method. The mold can be selected according to the desired size of the resin layer formed on the side surface of the battery stack on the side surface of the battery stack. Therefore, the dimension of the second resin layer that covers the side surface of the first resin layer and the side surface of the battery stack can be adjusted. That is, it is possible to suppress the dimensional variation of the second resin layer formed as described above.

  Further, when it is preferable not to cover the upper and lower end faces in the stacking direction of the battery stack with the resin layer, for example, before forming the second resin layer, the upper and lower ends in the stacking direction of the battery stack are preferably formed. The upper and lower end faces in the stacking direction of the battery stack can be protected by the jig that holds the end faces so as to sandwich the end faces. Alternatively, in this case, a masking tape can be attached to the upper and lower end faces in the stacking direction of the battery stack.

  FIG. 1C illustrates an embodiment after performing the step (c) according to the present disclosure. That is, FIG. 1C shows an aspect in which the second resin layer 22 is formed on the side surface of the first resin layer 21 and the side surface of the battery stack 20.

≪All-solid-state battery≫
The all-solid-state battery of the present disclosure manufactured by the above-described method includes a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer, which are stacked in this order. A battery stack including two or more unit batteries is provided, wherein at least one of a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer is a battery stack. In the side surface of the first resin layer having an extending portion extending outward from the other layer, and a gap is formed between the extending portions, the first resin layer filling the gap, and It has a first resin layer and a second resin layer covering the side surface of the battery stack.

  In addition, the side surface of the battery stack is a surface configured by the outer edge of each layer of the unit battery included in the battery stack.

  For example, FIG. 2 is a schematic cross-sectional view illustrating an example of the all solid state battery of the present disclosure. The all-solid-state battery 100 of the present disclosure has a battery stack 10 including unit cells 6a, 6b, 6c, and 6d. As shown in FIG. 2, the solid electrolyte layer 3b and the solid electrolyte layer 3c are each formed on another side surface (for example, the positive electrode active material layer 2b, the positive electrode current collector layer 1b (1c ), And extending portions 30b and 30c extending outward from the positive electrode active material layer 2c), and a gap is formed between the extending portions 30b and 30c. A first resin layer, and a first resin layer 11 and a second resin layer 12 covering side surfaces of the battery stack.

<Battery stack>
In the present disclosure, the battery stack includes two or more unit batteries in which a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are stacked in this order. . That is, in the present disclosure, the number of unit batteries included in the battery stack may be two or more, and the number of unit batteries can be arbitrarily set according to the purpose and application.

  For example, the battery stack 10 shown in FIG. 2 has four unit batteries 6a, 6b, 6c and 6d. The unit battery 6a is formed by laminating a positive electrode current collector layer 1a, a positive electrode active material layer 2a, a solid electrolyte layer 3a, a negative electrode active material layer 4a, and a negative electrode current collector layer 5a (5b) in this order. The unit battery 6b is formed by laminating a negative electrode current collector layer 5a (5b), a negative electrode active material layer 4b, a solid electrolyte layer 3b, a positive electrode active material layer 2b, and a positive electrode current collector layer 1b (1c) in this order. . The unit battery 6c is formed by stacking a positive electrode current collector layer 1b (1c), a positive electrode active material layer 2c, a solid electrolyte layer 3c, a negative electrode active material layer 4c, and a negative electrode current collector layer 5c (5d) in this order. . The unit battery 6 is formed by laminating a negative electrode current collector layer 5c (5d), a negative electrode active material layer 4d, a solid electrolyte layer 3d, a positive electrode active material layer 2d, and a positive electrode current collector layer 1d in this order.

  The battery stack 20 shown in FIG. 1A is an embodiment having eleven unit batteries 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6j, 6k, and 6l. . For details of the configuration of each unit battery, refer to the description of the unit battery in the battery stack 10 described above.

  In the present disclosure, the battery stack may be a monopolar battery stack or a bipolar battery stack.

  In the case of a monopolar battery stack, two unit batteries adjacent to each other in the stacking direction may have a monopolar configuration in which a positive electrode current collector layer or a negative electrode current collector layer is shared. For example, as shown in FIG. 2, adjacent unit batteries 6a and 6b share a negative electrode current collector layer 5a (5b), and adjacent unit cells 6b and 6c share a positive electrode current collector layer. 1b (1c), the adjacent unit cells 6c and 6d share the negative electrode current collector layer 5c (5d), and these unit cells 6a, 6b, 6c and 6d are combined into a monopolar A battery stack 10 of a mold type is formed.

  In the case of a bipolar battery stack, two unit batteries adjacent to each other in the stacking direction have a bipolar configuration in which a positive / negative current collector layer used as both a positive electrode and a negative electrode current collector layer is shared. Good. Thus, for example, a battery stack may be a stack of three unit batteries sharing a positive / negative current collector layer used as both a positive and negative electrode current collector layer, and specifically, a positive electrode current collector Body layer, positive electrode active material layer, solid electrolyte layer, negative electrode active material layer, positive electrode / negative electrode current collector layer, positive electrode active material layer, solid electrolyte layer, negative electrode active material layer, positive electrode / negative electrode current collector layer, positive electrode active material A layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer can be provided in this order (not shown). In this case, since the “positive electrode / negative electrode current collector layer” is used as both the positive electrode and the negative electrode current collector layer, the “positive electrode current collector layer” or the “negative electrode current collector layer” in the present disclosure is used. Applies to both.

  In the present disclosure, at least one layer of the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer is on the side surface of the battery stack more than other layers. If there is an extending portion extending outward and a gap is formed between the extending portions, the layer having the extending portion is a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer. It is not limited to any of the negative electrode active material layer and the negative electrode current collector layer.

  Note that, in a stacked all-solid-state battery represented by a lithium-ion battery, in order to reliably and smoothly move lithium ions released from the positive electrode active material layer to the negative electrode active material layer during charging, the negative electrode active material layer and the negative electrode It is preferable that the current collector layer be formed in a larger area than the positive electrode active material layer and the positive electrode current collector layer. Therefore, it is preferable that the negative electrode active material layer, the negative electrode current collector layer, and the solid electrolyte layer have an extension.

  Further, the all-solid-state battery of the present disclosure has a positive electrode current collection tab electrically connected to the positive electrode current collector layer, and has a negative electrode current collection tab electrically connected to the negative electrode current collector layer. It may be. In this case, these current collection tabs may protrude from the resin layer. According to this configuration, electric power generated in the battery stack can be extracted to the outside via the current collecting tab.

  Further, the positive electrode current collector layer may have a positive electrode current collector protrusion projecting in the surface direction, and a positive electrode current collector tab may be electrically connected to the positive electrode current collector protrusion. . Similarly, the negative electrode current collector layer may have a negative electrode current collector protrusion, and the negative electrode current collector tab may be electrically connected to the negative electrode current collector protrusion.

  In the all solid state battery of the present disclosure, the battery stack can be constrained in the stacking direction. Thereby, at the time of charge and discharge, the conductivity of ions and electrons between each layer and between the layers of the all-solid-state battery stack can be improved, and the battery reaction can be further promoted.

  Hereinafter, each member related to the battery stack will be described in detail. In addition, in order to easily understand the present disclosure, each member according to the battery stack of the all-solid-state lithium ion secondary battery will be described as an example, but the all-solid-state battery of the present disclosure is limited to a lithium-ion secondary battery. And can be widely applied.

(Positive electrode current collector layer)
The conductive material used for the positive electrode current collector layer is not particularly limited, and a material that can be used for an all-solid-state battery can be appropriately adopted. For example, the conductive material used for the positive electrode current collector layer may be, but is not limited to, SUS, aluminum, copper, nickel, iron, titanium, or carbon.

  The shape of the positive electrode current collector layer is not particularly limited, and examples thereof include a foil shape, a plate shape, and a mesh shape. Among these, a foil shape is preferred.

(Positive electrode active material layer)
The positive electrode active material layer contains at least a positive electrode active material, and preferably further contains a solid electrolyte described later. In addition, additives used in the positive electrode active material layer of the all-solid battery, such as a conductive additive or a binder, can be included in accordance with the intended use or intended purpose.

The material of the positive electrode active material is not particularly limited. For example, the positive electrode active material is lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ , Li _{1 + x} Li-Mn spinel or the like with a composition represented by Mn _{2- xy My} O ₄ (M is at least one metal element selected from Al, Mg, Co, Fe, Ni, and Zn) , But is not limited thereto.

  The conductive assistant is not particularly limited. For example, the conductive additive may be, but is not limited to, a carbon material such as VGCF (vapor-grown carbon fiber, vapor grown carbon fiber) and carbon nanofiber, and a metal material.

  The binder is not particularly limited. For example, the binder may be a material such as, but not limited to, polyvinylidene fluoride (PVdF), carboxymethyl cellulose (CMC), butadiene rubber (BR) or styrene butadiene rubber (SBR).

(Solid electrolyte layer)
The solid electrolyte layer contains at least a solid electrolyte. The solid electrolyte is not particularly limited, and a material that can be used as a solid electrolyte for an all-solid battery can be used. For example, the solid electrolyte may be, but is not limited to, a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like.

Examples of the sulfide solid electrolyte include, but are not limited to, a sulfide-based amorphous solid electrolyte, a sulfide-based crystalline solid electrolyte, and an aldirodite-type solid electrolyte. Examples of specific sulfide solid _{electrolyte, Li 2 S-P 2 S} 5 based _{(Li 7 P 3 S 11,} Li 3 PS 4, Li 8 P 2 S 9 , _{etc.), Li 2 S-SiS 2} , LiI _{-Li 2 S-SiS 2, LiI} -Li 2 S-P 2 S 5, LiI-LiBr-Li 2 S-P 2 S 5, Li 2 S-P 2 S 5 -GeS 2 (Li 13 GeP 3 S 16 , _Li 10 _GeP 2 _{S 12, etc.), LiI-Li 2 S-} P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5, Li 7-x PS 6-x Cl x , and the like; or combinations thereof But not limited thereto.

Examples of the oxide solid _{electrolyte, Li 7 La 3 Zr 2 O} 12, Li 7-x La 3 Zr 1-x Nb x O 12, Li 7-3x La 3 Zr 2 Al x O 12, Li 3x La 2 / _{3-x TiO 3, Li 1} + x Al x Ti 2-x (PO 4) 3, Li 1 + x Al x Ge 2-x (PO 4) 3, Li 3 PO 4, or _{Li 3 + x PO 4-x} N x (LiPON ) And the like, but are not limited thereto.

(Polymer electrolyte)
Examples of the polymer electrolyte include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

  The solid electrolyte may be glass or crystallized glass (glass ceramic). Further, the solid electrolyte layer may contain a binder or the like as necessary, in addition to the above-described solid electrolyte. As a specific example, it is the same as the “binder” listed in the above “positive electrode active material layer”, and the description is omitted here.

(Negative electrode active material layer)
The negative electrode active material layer contains at least the negative electrode active material, and preferably further contains the solid electrolyte described above. In addition, additives used in the negative electrode active material layer of the all-solid-state battery, such as a conductive additive or a binder, can be included in accordance with the intended use or intended purpose.

  The material of the negative electrode active material is not particularly limited, and is preferably capable of inserting and extracting metal ions such as lithium ions. For example, the negative electrode active material may be an alloy-based negative electrode active material or a carbon material, but is not limited thereto.

  The alloy-based negative electrode active material is not particularly limited, and examples thereof include a Si alloy-based negative electrode active material and a Sn alloy-based negative electrode active material. Examples of the Si alloy-based negative electrode active material include silicon, silicon oxide, silicon carbide, silicon nitride, and solid solutions thereof. Further, the Si alloy-based negative electrode active material can include elements other than silicon, for example, Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, and the like. Examples of the Sn alloy-based negative electrode active material include tin, tin oxide, tin nitride, and solid solutions thereof. In addition, the Sn alloy-based negative electrode active material can include elements other than tin, for example, Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, and the like. Among these, a Si alloy-based negative electrode active material is preferable.

  The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, and graphite.

  As for the solid electrolyte, conductive auxiliary agent, binder, and other additives used in the negative electrode active material layer, those described in the above-mentioned items of the “positive electrode active material layer” and “solid electrolyte layer” can be appropriately adopted. .

(Negative electrode current collector layer)
The conductive material used for the negative electrode current collector layer is not particularly limited, and a material that can be used for an all solid state battery can be appropriately adopted. For example, the conductive material used for the negative electrode current collector layer may be, but is not limited to, SUS, aluminum, copper, nickel, iron, titanium, carbon, or the like.

  The shape of the negative electrode current collector layer is not particularly limited, and examples thereof include a foil shape, a plate shape, and a mesh shape. Among these, a foil shape is preferred.

  In the present disclosure, the second resin layer covers the side surface of the all-solid-state battery stack. Thereby, it is not necessary to have an exterior body such as a laminate film or a metal can outside the all-solid-state battery of the present disclosure. Therefore, the all-solid-state battery of the present disclosure is more compact than a conventional all-solid-state battery that requires an exterior body, which also leads to an improvement in the energy density of the battery. However, one embodiment of the present disclosure may further include these exterior bodies.

  Further, in the all-solid battery of the present disclosure, the upper end face and the lower end face in the stacking direction of the battery stack are covered with a film or the like, and at least the side face of the all-solid battery stack is the second resin layer. May be an all-solid-state battery covered with a. Further, the all-solid-state battery of the present disclosure may be an all-solid-state battery in which the upper end surface and / or the lower end surface in the stacking direction of the all-solid battery stack are also covered with a resin layer.

<Resin layer>
The all solid state battery of the present disclosure has a first resin layer and a second resin layer.

  The first resin layer fills (covers) the gap between the two extending portions on the side surface of the battery stack. For example, as shown in FIG. 2, on the side surface of the battery stack 10, a gap formed between the extending portions 30 b and 30 c is filled with the first resin layer 11.

  The second resin layer covers (covers) the side surfaces of the first resin layer and the battery stack. For example, as shown in FIG. 2, the second resin layer 12 covers the first resin layer 11 and the side surfaces of the battery stack 10.

  In the present disclosure, the resin materials constituting the first resin layer and the second resin layer (that is, the first resin and the second resin) are as described above.

  In addition, the first resin layer and the second resin layer may contain an additive such as an inorganic filler in addition to the resin material. Note that the additive contained in the first resin layer and the additive contained in the second resin layer may be the same or different.

The material used for the inorganic filler is not particularly limited as long as it can stably exist in the all-solid-state battery. For example, oxides (alumina (Al ₂ O ₃ ), silica (SiO ₂ ), titania (TiO ₂ ), zirconia (ZrO ₂ ), other CeO ₂ , Y ₂ O ₃ , La ₂ O ₃ , LiAlO ₂ , Li ₂ O, BeO, B ₂ O ₃ , Na ₂ O, MgO, P ₂ O ₅ , CaO, Cr ₂ O ₃ , Fe ₂ O ₃ , ZnO, etc., porous composite ceramics (zeolite, sepiolite, palygorskite, etc.), nitriding things _{(Si 3 N 4, BN,} AIN, TiN, Ba 3 N 2 , etc.), carbides _{(SiC, ZrC, B 4 C} ), carbonates _(MgCO 3, CaCO _3, etc.), or sulfates _(CaSO 4, BaSO ₄ ) and the like are used as the inorganic filler, but are not limited thereto. The material used for these inorganic fillers may be a single material or a mixture of two or more types.

  The shape of the inorganic filler is not particularly limited, and may be a sphere, an ellipse, a fiber, a scale, or the like.

<Types of all solid state batteries>
In the present disclosure, examples of the type of the all-solid battery include an all-solid lithium-ion battery, an all-solid sodium-ion battery, an all-solid magnesium-ion battery, and an all-solid calcium-ion battery. Among them, all solid lithium ion batteries and all solid sodium ion batteries are preferable, and all solid lithium ion batteries are particularly preferable.

  Further, the all-solid-state battery of the present disclosure may be a primary battery or a secondary battery, and among them, a secondary battery is preferable. This is because the secondary battery can be repeatedly charged and discharged, and is useful as, for example, a vehicle-mounted battery. Therefore, it is preferable that the all solid state battery of the present disclosure is an all solid state lithium ion secondary battery.

1a, 1b, 1c, 1d Positive electrode current collector layer 1e, 1f, 1g, 1h, 1j, 1k, 1 Positive electrode current collector layer 2a, 2b, 2c, 2d Positive electrode active material layer 2e, 2f, 2g, 2h, 2j , 2k, 2l positive electrode active material layers 3a, 3b, 3c, 3d, solid electrolyte layers 3e, 3f, 3g, 3h, 3j, 3k, 3l solid electrolyte layers 4a, 4b, 4c, 4d negative electrode active material layers 4e, 4f, 4g, 4h, 4j, 4k, 4l Negative electrode active material layers 5a, 5b, 5c, 5d Negative electrode current collector layers 5e, 5f, 5g, 5h, 5j, 5k, 5l Negative electrode current collector layers 6a, 6b, 6c, 6d , 6e, 6f, 6g, 6h, 6j, 6k, 6l Unit battery 10, 20 Battery stack 11, 21 First resin layer 12, 22 Second resin layer 30b Extension of solid electrolyte layer 3b 30c Solid electrolyte Extension of layer 3c 100 All solid state battery

Claims (1)

A method for manufacturing an all-solid-state battery including the following steps:
(A) Prepare a battery laminate including two or more unit batteries in which a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are laminated in this order. Wherein, at least one of the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer is a side surface of the battery stack. Has an extending portion extending outward from other layers, and a gap is formed between the extending portions;
(B) filling the gap with a first resin by a capillary underfill method using reduced pressure, and curing the first resin to form a first resin layer; and (c) injection A molding method, a transfer molding method, or a dipping molding method covers a side surface of the first resin layer and a side surface of the battery stack with a second resin, and cures the second resin to form a second resin. Forming a resin layer.

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