US 12,431,569 B2
Lithium secondary battery and method of fabricating the same
Jong Hyuk Lee, Daejeon (KR); and Su Hee Han, Daejeon (KR)
Assigned to SK ON CO., LTD., Seoul (KR)
Filed by SK INNOVATION CO., LTD., Seoul (KR)
Filed on Jul. 27, 2021, as Appl. No. 17/443,685.
Claims priority of application No. 10-2020-0095533 (KR), filed on Jul. 30, 2020.
Prior Publication US 2022/0037728 A1, Feb. 3, 2022
Int. Cl. H01M 50/227 (2021.01); H01M 10/0525 (2010.01); H01M 50/211 (2021.01)
CPC H01M 50/227 (2021.01) [H01M 10/0525 (2013.01); H01M 50/211 (2021.01)] 12 Claims
OG exemplary drawing
 
1. A lithium secondary battery, comprising:
stack structures, each of the stack structures including a plurality of pouch cells; and
an elastic foam layer formed on an outer surface of at least two of the plurality of pouch cells,
wherein a tensile modulus of the elastic foam layer is from 200 MPa to 800 MPa,
wherein a porosity of the elastic foam layer is from 60% to 90%,
wherein the elastic foam layer includes a cured product of a composition including a foaming agent, a polyol and an isocyanate, and the foaming agent is included in an amount from 0.1 wt % to 5 wt % based on a total weight of the composition,
wherein the elastic foam layer is disposed on each of two outermost surfaces of the stack structure,
a thickness of the elastic foam layer is from 0.1 mm to 10 mm, and
the elastic foam layer is a film layer having a single layer structure,
wherein the elastic foam layer is not disposed on facing surfaces of two different pouch cells within one of the stack structures, and
the elastic foam layer is disposed on facing surfaces of two different stack structures of pouch cells.