# US 12,002,974 B2 · Pouch type secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,974 B2 - Document ID: US12002974B2 - Status: Granted - Kind: B2 - Application number: 16/621,814 - Filed: 2018-11-06 - Published: 2020-04-23 - Granted: 2024-06-04 - Earliest claimed: 2017-11-23 - Assignees: LG Energy Solution, Ltd. - Applicants: LG Chem, Ltd. - Inventors: Yong Su Choi; Sang Hun Kim; Min Hyeong Kang; Hyung Kyun Yu; Soo Ji Hwang; Na Yoon Kim; Yong Kim - Web page: https://patentgrep.com/patent/US12002974B2 ## CPC - H01M 50/178: for pouch or flexible bag cells - H01M 50/105: Pouches or flexible bags - H01M 50/553: Terminals adapted for prismatic, pouch or rectangular cells - H01M 50/578: in response to pressure - H01M 50/119: Metals - H01M 50/121: Organic material - H01M 50/129: with two or more layers of only organic material - H01M 50/534: characterised by the material of the leads or tabs - H01M 50/536: characterised by the method of fixing the leads to the electrodes, e.g. by welding - H01M 50/55: on the same side of the cell - H01M 50/557: Plate-shaped terminals - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A pouch type secondary battery according to the present invention includes: an electrode assembly; a battery case accommodating the electrode assembly in an inside thereof; an electrode tab protruding from the electrode assembly; a first electrode lead having an inner end connected to the electrode tab; a second electrode lead having an inner end coupled to an outer end of the first electrode lead and an outer end extending outside of the battery case; a connection part coupling the first and second electrode leads to each other; an insulation part fused around a portion of each of the first and second electrode leads, the insulation part bonding the first and second electrode leads to the battery case; and a fusion prevention part located at a position at one surface of the first electrode lead, the fusion prevention part preventing the first electrode lead from being fused to the insulation part. ## Claims ### Claim 1 A pouch type secondary battery comprising: an electrode assembly in which a positive electrode and a negative electrode and a separator are alternately laminated; a battery case accommodating the electrode assembly in an inside thereof; an electrode tab connected to the electrode assembly and protruding from one side of the electrode assembly; a first electrode lead having an inner end electrically connected to the electrode tab; a second electrode lead having an inner end mechanically and electrically coupled to an outer end of the first electrode lead and an outer end extending from the inside to an outside of the battery case in a first direction; a connection part mechanically and electrically coupling a first part of a first surface of the first electrode lead and a first surface of the second electrode lead to each other; an insulation part fused around a first portion of each of the first and second electrode leads, the insulation part bonding the first portion of each of the first and second electrode leads to the battery case; and a fusion prevention part located at a second portion of the first electrode lead, the second portion being a second part of the first surface of first electrode lead that does not extend between the first and second electrode leads, the fusion prevention part preventing the second portion of the first electrode lead from being fused to the insulation part, wherein the fusion prevention part is entirely disposed within the insulation part, wherein the fusion prevention part has a length of 1-4 mm extending in the first direction, the fusion prevention part being configured to reduce an adhesion area between the first electrode lead and the insulation part, thereby decreasing a minimum internal pressure of the battery case at which the first and second electrode leads detach from each other. ### Claim 2 (depends on 1) The pouch type secondary battery of claim 1, wherein the fusion prevention part is located between the connection part and the inside of the battery case. ### Claim 3 (depends on 1) The pouch type secondary battery of claim 1, wherein the fusion prevention part is an abraded portion of the first surface of the first electrode lead. ### Claim 4 (depends on 1) The pouch type secondary battery of claim 1, wherein the fusion prevention part is a non-surface-treated portion of the first surface of the first electrode lead. ### Claim 5 (depends on 4) The pouch type secondary battery of claim 4, wherein a remaining portion of the first surface of the first electrode lead is surface-treated. ### Claim 6 (depends on 1) The pouch type secondary battery of claim 1, wherein the insulation part comprises an acid-treated polyolefin-based resin. ### Claim 7 (depends on 6) The pouch type secondary battery of claim 6, wherein the polyolefin-based resin comprises polypropylene. ### Claim 8 (depends on 1) The pouch type secondary battery of claim 1, wherein the fusion prevention part is a tape attached to the second portion of the first surface of the first electrode lead. ### Claim 9 (depends on 8) The pouch type secondary battery of claim 8, wherein the tape comprises normal polypropylene that is not acid-treated. ### Claim 10 (depends on 1) The pouch type secondary battery of claim 1, wherein the fusion prevention part is a film attached to the insulation part, the film contacting the second portion of the first surface of the first electrode lead. ### Claim 11 (depends on 10) The pouch type secondary battery of claim 10, wherein the film comprises normal polypropylene that is not acid-treated. ### Claim 12 (depends on 1) The pouch type secondary battery of claim 1, wherein a bonding force between the fusion prevention part and a confronting surface of the first electrode lead or the insulation part is less than a bonding force between the first or second electrode lead and the connection part. ### Claim 13 (depends on 1) The pouch type secondary battery of claim 1, wherein the connection part is made of a conductive polymer comprising an electrically conductive material. ### Claim 14 (depends on 1) The pouch type secondary battery of claim 1, wherein the connection part has a thickness of 1 μm to 500 μm. ### Claim 15 (depends on 1) The pouch type secondary battery of claim 1, wherein the insulation part surrounds a location at which the first and second electrode leads are connected to each other by the connection part.