# US 12,763,379 B2 · Prismatic secondary battery having improved stability > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,763,379 B2 - Document ID: US12763379B2 - Status: Granted - Kind: B2 - Application number: 18/566,997 - Filed: 2023-04-04 - Published: 2024-08-08 - Granted: 2026-10-13 - Earliest claimed: 2022-04-05 - Assignees: LG Energy Solution, Ltd. - Applicants: LG Energy Solution, Ltd. - Inventors: Cheon Hee Bok; Joo Hwan Sung - Web page: https://patentgrep.com/patent/US12763379B2 ## CPC - H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)} - H01M 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators - H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence) - H01M 50/54: Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges - H01M 50/55: on the same side of the cell - H01M 50/553: Terminals adapted for prismatic, pouch or rectangular cells - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY ## Abstract Disclosed herein relates to an electrode assembly including: a plurality of unit cells, each unit cell comprising a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; and a protective stack layer on an outermost part of the electrode assembly, comprising a positive electrode foil, a negative electrode foil and a separator between the positive electrode foil and the negative electrode foil and on outer surfaces of the positive electrode foil and the negative electrode foil. ## Claims ### Claim 1 An electrode assembly, comprising: a plurality of unit cells, each unit cell comprising a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; and a protective stack layer on an outermost part of the electrode assembly, comprising a positive electrode foil, a negative electrode foil and a separator between the positive electrode foil and the negative electrode foil and on outer surfaces of the positive electrode foil and the negative electrode foil. ### Claim 2 (depends on 1) The electrode assembly of claim 1, wherein when an outermost electrode of the electrode assembly is a positive electrode, the protective stack layer comprises a structure that is laminated in the order of: the negative electrode foil, the separator, the positive electrode foil, and the separator. ### Claim 3 (depends on 1) The electrode assembly of claim 1, wherein when an outermost electrode of the electrode assembly is a negative electrode, the protective stack layer comprises a structure that is laminated in the order of: the positive electrode foil, the separator, the negative electrode foil, and the separator. ### Claim 4 (depends on 1) The electrode assembly of claim 1, wherein the protective stack layer is disposed on both outermost parts of the electrode assembly. ### Claim 5 (depends on 1) The electrode assembly of claim 1, wherein the size of the protective stack layer is not smaller than the size of an outermost unit cell of the electrode assembly. ### Claim 6 (depends on 1) The electrode assembly of claim 1, wherein the positive electrode foil and the negative electrode foil comprise a positive electrode foil tab and a negative electrode foil tab, respectively, wherein the electrode assembly comprises a positive electrode tab and a negative electrode tab, and wherein the positive electrode foil tab is electrically connected to the positive electrode tab of the electrode assembly, and the negative electrode foil tab is electrically connected to the negative electrode tab of the electrode assembly. ### Claim 7 (depends on 6) The electrode assembly of claim 6, wherein the protective stack layer buffers an internal short-circuit occurring in the electrode assembly. ### Claim 8 A prismatic secondary battery, comprising: a housing in which at least one side forms an opening; an electrode assembly comprising a plurality of unit cells, each unit cell comprising a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode, and the plurality of unit cells being stored inside the housing; a cap plate comprising a positive electrode terminal and a negative electrode terminal electrically connected to a positive electrode tab and a negative electrode tab of the electrode assembly, and is joined to seal the opening of the housing; and an electrolyte, wherein the electrode assembly further comprises a protective stack layer on an outermost part of the electrode assembly, comprising a positive electrode foil, a negative electrode foil, and a separator between the positive electrode foil and the negative electrode foil; and on outer surfaces of the positive electrode foil and the negative electrode foil, respectively, wherein the positive electrode foil and the negative electrode foil comprise a positive electrode foil tab and a negative electrode foil tab, respectively, wherein the electrode assembly further comprises a positive electrode tab and a negative electrode tab, and wherein the positive electrode foil tab is electrically connected to the positive electrode tab of the electrode assembly, and the negative electrode foil tab is electrically connected to the negative electrode tab of the electrode assembly. ### Claim 9 (depends on 8) The prismatic secondary battery of claim 8, wherein when an outermost electrode of the electrode assembly is a positive electrode, the protective stack layer comprises a structure that is stacked in the order of: the negative electrode foil, the separator, the positive electrode foil, and the separator. ### Claim 10 (depends on 8) The prismatic secondary battery of claim 8, wherein when an outermost electrode of the electrode assembly is the negative electrode, the protective stack layer comprises a structure that is stacked in the order of: the positive electrode foil, the separator, the negative electrode foil, and the separator. ### Claim 11 (depends on 8) The prismatic secondary battery of claim 8, wherein a size of the protective stack layer is not smaller than a size of an outermost unit cell of the electrode assembly. ### Claim 12 (depends on 8) The prismatic secondary battery of claim 8, wherein the protective stack layer buffers an internal short-circuit occurring in the electrode assembly.