Deep pouch cell and method of manufacturing same

Patent metadata

Field	Value
Publication number	US-10992005-B2
Application number	US-201816212203-A
Country	US
Kind code	B2
Filing date	Dec 6, 2018
Priority date	Dec 6, 2018
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

An electrochemical pouch cell includes a pouch cell housing and an electrode assembly disposed in the housing. The housing is formed of a single blank that is progressively drawn to form first and second recesses in the sheet, where the first recess coincides with a portion of the second recess. The blank is then folded so that the recesses are aligned and open facing each other. The electrode assembly is disposed in the space defined within and between the recesses, and flange portions of the material surrounding the recesses are sealed together to form a sealed electrochemical cell in which one side of the cell is free of the flange. The progressive drawing process along with the configuration of the recesses allows the cell housing to have an increased depth relative to some conventional pouch cell housings.

First claim

I claim:

1. An electrochemical cell comprising a pouch cell housing and an electrode assembly disposed in the housing, wherein
the electrode assembly comprises a positive electrode, a negative electrode and a separator disposed between the positive electrode and the negative electrode, and the positive electrode, the separator and the negative electrode are stacked along a stack axis,
the electrode assembly further comprises a first major side that is perpendicular to the stack axis, a second major side that is parallel to the first major side, and a first minor side that is parallel to the stack axis and extends between the first major side and the second major side, and
the housing comprises a single sheet of a metal foil laminate material, and the sheet includes
a first sheet surface, a second sheet surface that is opposed to the first sheet surface, and a sheet peripheral edge that extends between the first sheet surface and the second sheet surface,
a first recess formed in the first sheet surface, the first recess including
a pair of parallel first recess first sides, a pair of parallel first recess second sides that are perpendicular to the first recess first sides, and a first recess endwall, where the first recess first sides and the first recess second sides adjoin the first recess endwall and cooperate to surround the first recess endwall, and

a second recess formed in the first sheet surface in a region of the sheet that includes the first recess, the second recess including
a pair of parallel second recess first sides, a pair of parallel second recess second sides that are perpendicular to the second recess first sides, and a second recess endwall, where the second recess first sides and the second recess second sides adjoin the second recess endwall and cooperate to surround the second recess endwall,

wherein prior to folding the sheet to form an enclosure that receives the electrode assembly,
the sheet peripheral edge resides in a plane,
the second recess endwall is offset relative to the plane,
the first recess endwall is offset relative to the plane such that the second recess endwall is disposed between the first recess endwall and the plane along an axis that is perpendicular to the plane,
the first recess first sides are parallel to the second recess first sides,
the first recess second sides are parallel to the second recess second sides,
the first recess first sides are coplanar with the second recess first sides, and
the second recess second sides are disposed between the sheet peripheral edge and the first recess second sides along an axis that is parallel to the plane, whereby
a first portion of the second recess is provided between the second recess second side and the first recess second side on one side of the first recess, and
a second portion of the second recess is provided between the second recess second side and the first recess second side on an opposed side of the first recess, and

following folding the sheet to form the enclosure that receives the electrode assembly,
the electrode assembly is disposed in the enclosure such that the first minor side is disposed in the first recess such that the first minor side faces the first recess endwall, the first major side is disposed in the first portion of the second recess such that the first portion of the second recess faces the first major side, the second major side is disposed in the second portion of the second recess such that the second portion of the second recess faces the second major side, and a first region of the sheet that is disposed between the first portion of the second recess and the sheet peripheral edge is bonded to a second region of the sheet that is disposed between the second portion of the second recess and the sheet peripheral edge.

2. The electrochemical cell of claim 1 , wherein the ratio (A)/(B) is 2, where (A) is a distance between the respective first recess second sides, and (B) is a distance between the second recess endwall and the plane.

3. The electrochemical cell of claim 1 , wherein following folding the sheet to form the enclosure that receives the electrode assembly, the first region and the second region as bonded together form a flange that protrudes outward along three sides of the cell housing so as to overlie a second minor side of the electrode assembly, a third minor side of the electrode assembly, and a fourth minor side of the electrode assembly, and
a fourth side of the cell housing that overlies the first minor side of the electrode assembly is free of the flange.

4. The electrochemical cell of claim 1 , wherein the first and second recesses each have the shape of a rectangular prism.

5. The electrochemical cell of claim 1 , wherein the pouch cell housing has a dimension in a direction parallel to the stack axis that is greater than twice the draw depth of the material used to form the pouch cell housing.

6. The electrochemical cell of claim 1 , wherein the metal foil laminate material comprises an aluminum foil layer that is sandwiched between polymer layers.

7. A method of forming an electrochemical cell having a pouch cell housing, the method steps comprising
providing a sheet of a metal foil laminate material, the sheet including a first sheet surface that resides in a plane, a second sheet surface that is opposed to the first sheet surface, and a sheet peripheral edge that extends between the first sheet surface and the second sheet surface,
providing an electrode assembly, the electrode assembly comprising a positive electrode, a negative electrode and a separator disposed between the positive electrode and the negative electrode, wherein the positive electrode, the separator and the negative electrode are stacked along a stack axis, and the electrode assembly further comprises a first major side that is perpendicular to the stack axis, a second major side that is parallel to the first major side, and a first minor side that is parallel to the stack axis and extends between the first major side and the second major side,
forming a first recess in the first sheet surface at a first location, the first recess comprising:
a pair of parallel first recess first sides,
a pair of parallel first recess second sides that are perpendicular to the first recess first sides, and
a first recess endwall that is offset from, and parallel to, the plane, where the first recess first sides and the first recess second sides adjoin the first recess endwall and cooperate to surround the first recess endwall, and the first recess first sides and the first recess second sides are each spaced apart from the sheet peripheral edge,

forming a second recess in the first sheet surface at the first location, the second recess including
a pair of parallel second recess first sides,
a pair of parallel second recess second sides that are perpendicular to the second recess first sides, and
a second recess endwall that is offset from, and parallel to, the plane and the first recess endwall, wherein
the second recess first sides and the second recess second sides adjoin the second recess endwall and cooperate to surround the second recess endwall,
the second recess first sides and the second recess second sides are each spaced apart from the sheet peripheral edge,
the second recess endwall is disposed between the first recess endwall and the plane along an axis that is perpendicular to the plane,
the first recess first sides are parallel to, and coplanar with, the second recess first sides,
the first recess second sides are parallel to the second recess second sides, and
the second recess second sides are disposed between the sheet peripheral edge and the first recess second sides along an axis that is parallel to the pla

Assignees

• Robert Bosch Battery Systems Llc
• Bosch Gmbh Robert

Inventors

• Levin Eugene

Classifications

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title

• H01M50/548

  on opposite sides of the cell · CPC title

• H01M50/119

  Metals · CPC title

• H01M50/124 Primary

  having a layered structure · CPC title