JP2019153514A - All-solid battery - Google Patents

Abstract

To provide an all-solid battery which allows an all-solid battery laminate encased in a battery case to be pressurized easily and to be sealed satisfactorily.SOLUTION: An all-solid battery 100 according to the present invention comprises: an all-solid battery laminate 10; and a battery case in which the all-solid battery laminate is sealed. The battery case includes two cup-shaped members 20 each composed of a laminate film, and a belt-shaped member 30 composed of a laminate film. Bottom parts 22 of the two cup-shaped members both front the all-solid battery laminate, and the two cup-shaped members are arrange so as to be opposed to each other over the all-solid battery laminate. The belt-shaped member is wound around faces of the all-solid battery laminate, which are not covered by the two cup-shaped members, and glued to side parts 24 of the two cup-shaped members; and opposing end portions 32 of the belt-shaped member are glued to each other at inner faces thereof.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an all solid state battery.

  As a power source for driving an electric motor of a hybrid vehicle or the like, an all solid state battery such as an all solid state lithium ion battery has attracted attention. Such an all solid state battery 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 has an at least one unit all solid state battery. A laminate is provided. Various battery cases are used to enclose the all-solid battery stack.

  Patent Document 1 discloses a battery including a battery cell and a container that accommodates the battery cell, the container having a lower surface, a side surface standing from the lower surface, and an opening provided on the upper surface side. And an upper lid having an upper surface, a side surface erected from the upper surface, and an opening provided on the lower surface side, wherein the side surface of the lower lid and the side surface of the upper lid are overlapped, and the battery cell accommodated in the container A battery is disclosed, characterized in that a terminal connected to is fixed to a member constituting the side surface of the container.

  Patent Document 2 discloses a battery module including a battery and an exterior body that accommodates the battery, and the battery includes a positive electrode layer, a negative electrode layer, and an electrolyte disposed between the positive electrode layer and the negative electrode layer. A battery cell, and a container that can store the battery cell, the container including a lower surface, a side surface that stands from the lower surface and surrounds the lower surface, and an upper surface opening formed to allow the battery cell to be stored to pass therethrough. And a lower lid having a first contact portion extending on the outer periphery of the upper surface opening and projecting from the side surface, and an upper lid having a second contact portion in contact with the first contact portion and closing the upper surface opening. The container is hermetically sealed by a close contact portion projecting from the side surfaces of the lower lid and the upper lid, in which the first contact portion and the second contact portion are in close contact, and the exterior body is provided with the close contact portion. A battery module characterized by having a recess is disclosed.

  In Patent Document 3, in a lithium secondary battery using lithium or a lithium compound as a negative electrode active material, the battery container is made of a material mainly made of aluminum, and the coating layer does not dissolve in the electrolyte on the inner wall surface of the container A lithium secondary battery characterized in that is formed is disclosed.

  Patent Document 4 discloses an assembled battery in which a plurality of laminate cells are arranged in the thickness direction, and the electrode plates are encased in a laminate film and sealed in a plate shape, and electrode terminals project from the center in the thickness direction to the outside. A holding member for holding one or a plurality of laminate cells, wherein each laminate cell is directly or indirectly sandwiched by a pair of elastic portions having the same elastic characteristics from both sides in the thickness direction. An elastic part that urges one laminate cell and another elastic part adjacent to the one laminate cell, and that urges the other laminate cell adjacent to the one laminate cell. An assembled battery is disclosed that is arranged so as to be elastically deformed independently of each other.

JP 2012-084247 A JP 2012-084248 A JP-A-8-167401 JP 2005-108693 A

  When a container (battery case) made of a material having high rigidity such as an aluminum plate or stainless steel (SUS) plate is used to accommodate the all-solid-state battery stack, the all-solid-state battery stack inside the container is sufficiently restrained. In some cases, pressurization was not possible. In this case, there is a possibility that the internal resistance of the all-solid battery stack is increased and the performance of the battery is lowered. In this case, since it is difficult to ensure the adhesion of the welded portion, there is a possibility that the sealing property of the container cannot be ensured.

  Therefore, there is a need to provide an all solid state battery that can easily pressurize the all solid state battery stack accommodated in the battery case and can be well sealed.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention is as follows:
<Aspect 1> An all-solid battery laminate having at least one unit all-solid battery, wherein the unit all-solid battery comprises a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and An all-solid battery stack having a negative electrode current collector layer in this order, and a battery case enclosing the all-solid battery stack;
The battery case comprises two laminated film cup-shaped members, and a laminated film strip-shaped member,
The two cup-shaped members are arranged such that the bottoms of the two cup-shaped members are all facing the all-solid battery stack and are opposed to each other via the all-solid battery stack,
The band-shaped member is wound around the surface of the all-solid-state battery stack that is not covered by the two cup-shaped members, is bonded to the side portions of the two cup-shaped members, and is formed at both ends of the band-shaped member. Glued to each other at the sides,
All solid battery.

  ADVANTAGE OF THE INVENTION According to this invention, the all-solid-state battery which can pressurize the all-solid-state battery laminated body accommodated in the battery case easily and can be sealed favorable can be provided.

FIG. 1 shows a schematic diagram of an all-solid battery of the present invention. FIG. 1A shows a top view of the all solid state battery of the present invention, and FIG. 1B shows a cross-sectional view taken along line Ib-Ib in FIG. ) Shows a cross-sectional view taken along line Ic-Ic in FIG.

<All-solid battery>
As shown in FIG. 1, the all-solid battery 100 of the present invention is
An all-solid battery stack 10 having at least one unit all-solid battery, wherein the unit all-solid battery 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 All-solid-state battery stack 10 having layers in this order, and battery cases 20 and 30 enclosing all-solid-state battery stack 10
It has
The battery case includes two laminated film cup-like members 20 and a laminated film-made belt-like member 30;
The two cup-shaped members 20 are arranged such that the bottom portions 22 of the two cup-shaped members 20 face the all-solid battery stack 10 and face each other via the all-solid battery stack 10. ,
The band-shaped member 30 is wound around the surface of the all-solid-state battery stack that is not covered by the two cup-shaped members 20, is bonded to the side portions 24 of the two cup-shaped members, and the inside of the both ends 32 of the band-shaped member 30. They are glued together on the sides.

  The inventors of the present invention have found that with the above-described configuration, the all-solid-state battery stack accommodated in the battery case can be easily pressurized and sealed well. More specifically, the two cup-shaped members and the band-shaped members constituting the battery case are both made of a laminate film, so that the battery case is flexible as a whole while ensuring the hermeticity inside the battery case. Therefore, it is possible to facilitate the application of the restraining pressure to the all-solid battery stack.

  Moreover, in said structure, the terminal connected to a positive electrode collector layer and a negative electrode collector layer is exposed from arbitrary positions, for example from a cup-shaped member, or between a cup-shaped member and a strip | belt-shaped member. it can.

  The two cup-shaped members may be respectively disposed on the positive electrode current collector layer and the negative electrode current collector layer that will be located on the outermost side of the all solid battery stack, but the side surfaces of the all solid battery stack In other words, it is preferable that the positive electrode current collector layer and the negative electrode current collector layer are arranged on a plane perpendicular to the positive electrode current collector layer and the negative electrode current collector layer from the viewpoint of facilitating the application of the binding pressure to the all-solid battery stack.

  Below, the cup-shaped member and belt-shaped member which comprise a battery case are demonstrated.

<Cup-shaped member>
The cup-shaped member is a member made of two laminated films that are disposed so that the bottom faces the all-solid battery stack and faces each other via the all-solid battery stack. The cup-shaped member may have a recess.

  The depth of the concave portion of the cup-shaped member may be a depth sufficient to secure a side portion having a sufficient width to be bonded to the belt-shaped member, for example, 5 mm or more, 10 mm or more, or 15 mm or more. It may be 50 mm or less, 40 mm or less, 30 mm or less, or 20 mm or less.

  The thickness of the laminate film constituting the cup-shaped member may be sufficient to enable sealing of the all-solid battery laminate while ensuring flexibility, for example, 500 μm or less, 400 μm or less, 300 μm. Hereinafter, it may be 200 μm or less, or 100 μm or less, and may be 1 μm or more, 3 μm or more, 5 μm or more, 10 μm or more, 30 μm or more, 50 μm or more, or 70 μm or more.

  The laminate film constituting the cup-shaped member may be a film having a metal layer and a sealant material layer. As a metal layer used for a laminate film, for example, aluminum or stainless steel (SUS) steel can be used.

  As the sealant material layer, for example, polyolefin such as polypropylene, polyethylene, polystyrene, or polyvinyl chloride can be used.

  The laminate film may further have an optional base material layer made of a polyamide such as nylon, a polyester such as polyethylene terephthalate, or a thermoplastic resin such as the above polyolefin.

  An optional adhesive layer may be present between the above layers. Examples of the adhesive layer include a dry laminate adhesive and a hot melt adhesive.

  The laminated films constituting the two cup-shaped members may be the same type or different from each other.

<Strip member>
The belt-like member is wound around the surface of the all-solid-state battery laminate that is not covered by the two cup-like members, is bonded to the side portions of the two cup-shaped members, and is bonded to each other on the inner side surfaces of the two end portions. It is a member made of a laminate film.

  Here, the “both ends” mean portions of the band-shaped member that does not contact the all-solid battery stack when the band-shaped member is wound around the all-solid battery stack.

  The thickness of the laminate film constituting the belt-shaped member may be sufficient to ensure flexibility, for example, 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, or 100 μm or less, It may be 1 μm or more, 3 μm or more, 5 μm or more, 10 μm or more, 30 μm or more, 50 μm or more, or 70 μm or more.

  As the laminate film constituting the belt-like member, the laminate films mentioned for the cup-like member can be used. The laminate film constituting the belt-like member may be the same as or different from the laminate film constituting the two cup-like members.

  Next, each layer which comprises the laminated body for all-solid-state batteries in the all-solid-state battery of this invention is demonstrated.

  In the present invention, the “positive electrode current collector layer” referred to below means that at least one surface is in contact with the positive electrode active material layer, and only the positive electrode active material layer is present. The current collector layer may be in contact, or may be a current collector layer that can be shared by the positive electrode active material layer and the negative electrode active material layer. Similarly, the “negative electrode current collector layer” referred to below may be a current collector layer in contact with only the negative electrode active material layer, or a current collector that can be shared by the positive electrode active material layer and the negative electrode active material layer. It may be an electrical layer.

<Positive electrode current collector layer>
The conductive material used for the positive electrode current collector layer is not particularly limited, and any known material that can be used for an all-solid battery can be appropriately employed. Examples include stainless steel (SUS), aluminum, copper, nickel, iron, titanium, and carbon.

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

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

In the present disclosure, the positive electrode active material used is not particularly limited, and a known material is used. For example, sulfur (S), lithium sulfide (Li ₂ S), 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} Mn _2−xy M _y O ₄ (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn) Examples include, but are not limited to, heteroelement-substituted Li—Mn spinel.

  The conductive auxiliary agent is not particularly limited, and known ones are used. Examples thereof include, but are not limited to, carbon materials such as VGCF (vapor-grown carbon fiber, Vapor Carbon Carbon Fiber) and carbon nanofibers, and metal materials.

  It does not specifically limit as a binder, A well-known thing is used. Examples include, but are not limited to, materials such as polyvinylidene fluoride (PVdF), carboxymethylcellulose (CMC), butadiene rubber (BR), styrene butadiene rubber (SBR), or combinations thereof.

<Solid electrolyte layer>
The solid electrolyte layer includes at least a solid electrolyte. The solid electrolyte is not particularly limited, and a material that can be used as a solid electrolyte of an all-solid battery can be used. For example, a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like can be used.

Examples of the sulfide solid electrolyte include, for example, 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} -LiI-LiBr, Li 2 S-P 2 S 5 -GeS 2, LiI-Li 2 S-P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5, and Li ₂ S-P ₂ S _{5 and the} like; sulfide-based crystalline solid electrolytes such as Li ₁₀ GeP ₂ S ₁₂ , Li ₇ P ₃ S ₁₁ , Li ₃ PS ₄ , and Li _3.25 P _0.75 S ₄ As well as combinations thereof.

Examples of oxide solid electrolytes include Li ₂ O—B ₂ O ₃ —P ₂ O ₃ , Li ₂ O—SiO ₂ , Li ₂ O—P ₂ O _{5 and} other oxide amorphous solid electrolytes, Li ₅ La ₃ Ta ₂ O ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₃ PO _{(4-3 / 2w)} N _w (w <1), Li _3.6 Si _0.6 Examples thereof include, but are not limited to, oxide crystalline solid electrolytes such as P _0.4 O ₄ .

  The sulfide solid electrolyte or oxide solid electrolyte may be glass or crystallized glass (glass ceramic).

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

  Further, the solid electrolyte layer may contain a binder or the like as necessary in addition to the above-described solid electrolyte. A specific example is the same as the “binder” listed in the “positive electrode active material layer” described above, and a description thereof is omitted here.

<Negative electrode active material layer>
The negative electrode active material layer includes at least a negative electrode active material, and preferably further includes the solid electrolyte described above. In addition, an additive used for 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.

  In the present disclosure, the negative electrode active material used is not particularly limited as long as it can occlude and release metal ions such as lithium ions. Examples include, but are not limited to, metals such as Li, Sn, Si, or In, alloys of lithium and titanium, or carbon materials such as hard carbon, soft carbon, or graphite.

  As other additives such as a solid electrolyte, a conductive additive, and a binder used in the negative electrode active material layer, those described in the above-mentioned items of “positive electrode active material layer” and “solid electrolyte layer” can be appropriately employed. .

<Negative electrode current collector layer>
The conductive material used for the negative electrode current collector layer is not particularly limited, and a known material that can be used for an all-solid battery can be appropriately employed. Examples include stainless steel (SUS), aluminum, copper, nickel, iron, titanium, and carbon.

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

DESCRIPTION OF SYMBOLS 10 All-solid-state battery laminated body 20 Cup-shaped member 22 Bottom part of cup-shaped member 24 Side part of cup-shaped member 30 Band-shaped member 32 Both ends of band-shaped member 100 All-solid-state battery

Claims (1)

An all-solid battery stack having at least one unit all-solid battery, wherein the unit all-solid battery comprises 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 An all-solid battery stack having layers in this order, and a battery case enclosing the all-solid battery stack,
The battery case comprises two laminated film cup-shaped members, and a laminated film strip-shaped member,
The two cup-shaped members are arranged such that the bottoms of the two cup-shaped members are all facing the all-solid battery stack and are opposed to each other via the all-solid battery stack,
The band-shaped member is wound around the surface of the all-solid-state battery stack that is not covered by the two cup-shaped members, is bonded to the side portions of the two cup-shaped members, and is formed at both ends of the band-shaped member. Glued to each other at the sides,
All solid battery.

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