All-solid-state battery and method for producing the same

Patent metadata

Field	Value
Publication number	US-2020185779-A1
Application number	US-201916703508-A
Country	US
Kind code	A1
Filing date	Dec 4, 2019
Priority date	Dec 5, 2018
Publication date	Jun 11, 2020
Grant date	—

Abstract

The invention provides a laminated all-solid-state battery that can increase volumetric energy density and maintain the shape of the all-solid-state battery, as well as a method for producing the laminated all-solid-state battery. The all-solid-state battery comprises a battery stack having two or more unit cells and an exterior film sealing the battery stack, wherein the battery stack has a hexahedron shape formed by a top surface and bottom surface in the stacking direction and first, second, third and fourth side walls, the exterior film is a single film covering the battery stack from the top surface and bottom surface in a manner covering the fourth side wall, and condition (i) is satisfied when collector tabs protrude from the first or third side wall or condition (ii) is satisfied when collector tabs protrude from the second side wall, as well as a method for producing the all-solid-state battery.

First claim

1 . An all-solid-state battery comprising a battery stack with two or more unit cells, and an exterior film that seals the battery stack, wherein:
each unit cell is composed of a positive electrode collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer and a negative electrode collector layer, stacked in that order, the battery stack has a hexahedron shape formed by a top surface and bottom surface in the stacking direction, and first, second, third and fourth side walls, the first, second, third and fourth side walls being adjacent in that order, collector tabs of the battery stack protrude out from the first, second or third side wall, the exterior film is a single film covering the fourth side wall and sandwiching the battery stack from the top surface and bottom surface, the exterior film has: first and second main side covering parts respectively covering the top surface and bottom surface of the battery stack, and mutually facing first, second and third perimeter edge parts respectively on the first, second and third side walls of the battery stack, first boundary parts between the first perimeter edge parts and the second perimeter edge parts, second boundary parts between the second perimeter edge parts and the third perimeter edge parts, a third boundary part between the third perimeter edge parts and the part covering the fourth side wall of the battery stack, and a fourth boundary part between the part covering the fourth side wall of the battery stack, and the first perimeter edge parts, with the collector tabs satisfying the following condition (i) when the collector tabs protrude from the first or third side wall, and the collector tabs satisfying the following condition (ii) when the collector tabs protrude from the second side wall:
condition (i)
the first boundary parts are folded from the boundary line between the first side wall and the second side wall along the first side wall, and between the facing first perimeter edge parts,
the second boundary parts are folded from the boundary line between the second side wall and the third side wall along the third side wall, and between the facing third perimeter edge parts,
the third boundary part is folded from the boundary line between the third side wall and the fourth side wall along the third side wall, and between the facing third perimeter edge parts,
the fourth boundary part is folded from the boundary line between the fourth side wall and the first side wall along the first side wall, and between the facing first perimeter edge parts,
the facing first, second and third perimeter edge parts are joined together so that the battery stack is sealed by the exterior film,
the collector tabs protrude out from between the mutually facing and mutually joined first or third perimeter edge parts, and
the mutually joined second perimeter edge parts are folded along the second side wall;

condition (ii)
the first boundary parts are folded from the boundary line between the first side wall and the second side wall along the second side wall, and between the facing second perimeter edge parts,
the second boundary parts are folded from the boundary line between the second side wall and the third side wall along the second side wall, and between the facing second perimeter edge parts,
the third boundary part is folded from the boundary line between the third side wall and the fourth side wall along the third side wall, and between the facing third perimeter edge parts,
the fourth boundary part is folded from the boundary line between the fourth side wall and the first side wall along the first side wall, and between the facing first perimeter edge parts,
the facing first, second and third perimeter edge parts are joined together so that the battery stack is sealed by the exterior film,
the collector tabs protrude out from between the mutually facing and mutually joined second perimeter edge parts, and
the mutually joined first and third perimeter edge parts are folded along the first and third side walls, respectively.

2 . The all-solid-state battery according to claim 1 , wherein for condition (i),
when the collector tabs protrude from the first perimeter edge parts, the mutually joined third perimeter edge parts are folded along the third side wall, and when the collector tabs protrude from the third perimeter edge parts, the mutually joined first perimeter edge parts are folded along the first side wall.

3 . The all-solid-state battery according to claim 1 , wherein at the perimeter edge parts among the mutually joined first, second and third perimeter edge parts that are folded along the first, second and third side walls, the folding widths along the first, second and third side walls are no greater than the thickness in the stacking direction of the battery stack.

4 . The all-solid-state battery according to claim 1 , wherein the mutually joined first, second and third perimeter edge parts do not protrude outward from the battery stack in the stacking direction of the battery stack.

5 . The all-solid-state battery according to claim 1 , wherein at least one of the respective joining sites of the mutually joined first, second and third perimeter edge parts extends from a location between the top surface and bottom surface in the stacking direction of the battery stack.

6 . The all-solid-state battery according to claim 1 , wherein at least one of the respective joining sites of the mutually joined first, second, third and fourth perimeter edge parts extends from a location at the top surface or the bottom surface in the stacking direction of the battery stack.

7 . The all-solid-state battery according to claim 1 , wherein the battery stack has a rectangular solid shape, and the respective areas of the top surface and bottom surface are larger than the areas of all of the first, second, third and fourth side walls.

8 . The all-solid-state battery according to claim 1 , wherein the exterior film is an aluminum laminate film.

9 . A method for producing the all-solid-state battery according to claim 1 in which the collector tabs protrude from the first or third side wall, the method including the following steps:
(a) sandwiching the battery stack by the exterior film from the top surface and bottom surface, and covering the fourth side wall, so that the first, second and third perimeter edge parts of the exterior film and the first and second boundary parts are each mutually facing;
(b) joining together the facing second perimeter edge parts, first boundary parts and second boundary parts;
(c) folding the mutually joined second perimeter edge parts, first boundary parts and second boundary parts along the second side wall of the battery stack;
(d) carrying out the following steps (d-1) to (d-4) either simultaneously or in an arbitrary order:
(d-1) folding the first boundary parts of the exterior film from the boundary line between the first side wall and the second side wall, along the first side wall and between the facing first perimeter edge parts,
(d-2) folding the second boundary parts of the exterior film from the boundary line between the second side wall and the third side wall, along the third side wall and between the facing third perimeter edge parts,
(d-3) folding the third boundary part of the exterior film from the boundary line between the third side wall and the fourth side wall, along the third side wall and between the facing third perimeter edge parts, and
(d-4) folding the fourth boundary part of the exterior film from the boundary line between the fourth side wall and the first side wall, along the first side wall and between the

Assignees

• Toyota Motor Co Ltd

Inventors

• Kawakami Masatsugu
• Oguma Yasumasa
• Tsuno Hiroshi
• Nishino Hiroaki

Classifications

• H01M50/553

  Terminals adapted for prismatic, pouch or rectangular cells · CPC title

• H01M50/119

  Metals · CPC title

• H01M50/531

  Electrode connections inside a battery casing · CPC title

• H01M50/124

  having a layered structure · CPC title

• H01M10/0431

  Cells with wound or folded electrodes (H01M10/045 takes precedence) · CPC title