# US 10,319,959 B2 · Flexible secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,319,959 B2 - Document ID: US10319959B2 - Status: Granted - Kind: B2 - Application number: 14/677,296 - Filed: 2015-04-02 - Published: 2015-11-12 - Granted: 2019-06-11 - Earliest claimed: 2014-05-09 - Assignees: Samsung SDI Co., Ltd. - Applicants: Samsung SDI Co., Ltd. - Inventors: Ju-Hee Sohn; Naum Feygenson; Jun-Won Suh; Jeong-Doo Yi; Hyun-Hwa Song; Bong-Kyoung Park; Hye-Jung Lee - Web page: https://patentgrep.com/patent/US10319959B2 ## CPC - H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence) - H01M 50/105: Pouches or flexible bags - H01M 50/119: Metals - H01M 50/121: Organic material - H01M 50/129: with two or more layers of only organic material - H01M 50/136: Flexibility or foldability - H01M 50/159: Metals - H01M 50/16: Organic material - H01M 50/164: having a layered structure - H01M 50/184: characterised by their shape or structure - H01M 50/186: characterised by the disposition of the sealing members - H01M 50/124: having a layered structure - H01M 50/178: for pouch or flexible bag cells - H01M 50/55: on the same side of the cell - H01M 50/553: Terminals adapted for prismatic, pouch or rectangular cells - H01M 2220/30: Batteries in portable systems, e.g. mobile phone, laptop - 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 flexible secondary battery includes an electrode assembly, a first external cover that is located on a first surface of the electrode assembly, and a second external cover that is located on a second surface of the electrode assembly, the second external cover and the first external cover including a sealing portion where edges of the first external cover and the second external cover are attached to each other to seal the electrode assembly. At least one of the first external cover and the second external cover includes a stress-relief pattern in a center portion. ## Claims ### Claim 1 A flexible secondary battery, comprising: an electrode assembly; a first external cover that is located on a first surface of the electrode assembly; and a second external cover that is located on a second surface of the electrode assembly, the second external cover and the first external cover being connected to each other by a hinge side, and the second external cover and the first external cover including a sealing portion where edges of the first external cover and the second external cover are attached to each other to seal the electrode assembly, wherein at least one of the first external cover and the second external cover has a three-layer structure formed of a first insulation layer, a second insulation layer, and a metal layer between the first insulation layer and the second insulation layer, the at least one of the first external cover and the second external cover including a stress-relief pattern in the metal layer of the at least one of the first external cover and the second external cover, the stress-relief pattern extending across the at least one of the first external cover and the second external cover in a center portion, the stress-relief pattern including patterns in a form of wrinkles that relieve a compression stress or an expansion stress when the at least one of the first external cover and the second external cover of the flexible secondary battery is bent concavely or convexly, the stress-relief pattern extending in a direction perpendicular to a length direction of the flexible secondary battery and parallel to the hinge side connecting the first and second external covers. ### Claim 2 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein the center portion is spaced apart from the sealing portion. ### Claim 3 (depends on 2) The flexible secondary battery as claimed in claim 2, wherein a shape of the stress-relief pattern changes when the flexible secondary battery is bent. ### Claim 4 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein the sealing portion is flat. ### Claim 5 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein: the first external cover is concavely bendable, and the stress-relief pattern is located in the center portion of the first external cover. ### Claim 6 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein at least one of the first external cover and the second external cover further includes patterns on at least one side of the stress-relief pattern in the length direction of the flexible secondary battery. ### Claim 7 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein the stress-relief pattern is located in an xy-plane that is perpendicular to a z-axis toward which the flexible secondary battery is bendable. ### Claim 8 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein the stress-relief pattern includes irregular patterns. ### Claim 9 A flexible secondary battery, comprising: an electrode assembly; a first external cover that is located on a first surface of the electrode assembly, the first external cover including a three-layer structure formed of a first insulation layer, a second insulation layer, and a metal layer between the first insulation layer and the second insulation layer; and a second external cover that is located on a second surface of the electrode assembly, the second external cover and the first external cover being connected to each other by a hinge side, and the second external cover and the first external cover including a sealing portion where edges of the first external cover and the second external cover are attached to each other to seal the electrode assembly, the sealing portion being flat, wherein the metal layer of the first external cover includes a stress-relief pattern extending across the first external cover in a center portion thereof, the stress-relief pattern including patterns in a form of wrinkles that relieve a compression stress or an expansion stress when the first external cover of flexible secondary battery is bent concavely or convexly, the stress-relief pattern extending in a direction perpendicular to a length direction of the flexible secondary battery. ### Claim 10 (depends on 9) The flexible secondary battery as claimed in claim 9, wherein the center portion is spaced apart from the sealing portion. ### Claim 11 (depends on 9) The flexible secondary battery as claimed in claim 9, wherein a shape of the stress relief stress-relief pattern changes when the flexible secondary battery is curved. ### Claim 12 (depends on 9) The flexible secondary battery as claimed in claim 9, wherein the first external cover further includes patterns on at least one side of the stress-relief pattern in the length direction of the flexible secondary battery. ### Claim 13 (depends on 9) The flexible secondary battery as claimed in claim 9, wherein the stress-relief pattern is located in an xy-plane that is perpendicular to a z-axis toward which the flexible secondary battery is bent. ### Claim 14 (depends on 9) The flexible secondary battery as claimed in claim 9, wherein the stress-relief pattern includes irregular patterns. ### Claim 15 (depends on 1) The flexible secondary battery as claimed in claim 1, wherein the metal layer is aluminum or an aluminum alloy. ### Claim 16 (depends on 9) The flexible secondary battery as claimed in claim 9, wherein the metal layer is aluminum or an aluminum alloy.