# US 2014/0197796 A1 · Electric storage device, electric storage system, and manufacturing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197796 A1 - Document ID: US20140197796A1 - Status: Published application - Kind: A1 - Application number: 14/152,948 - Filed: 2014-01-10 - Published: 2014-07-17 - Earliest claimed: 2013-01-11 - Assignees: GS Yuasa International Ltd. - Applicants: GS Yuasa International Ltd. - Inventors: Takeshi SASAKI; Taro YAMAFUKU - Web page: https://patentgrep.com/patent/US20140197796A1 ## CPC - H01M 10/0587: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators - H01M 10/0431: {Cells with wound or folded electrodes (H01M10/045 takes precedence)} - H01M 10/049: {Processes for forming or storing electrodes in the battery container} - H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence) - H01M 50/538: Connection of several leads or tabs of wound or folded electrode stacks - H02J 7/865: {Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence)} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 50/55: on the same side of the cell - H01M 50/553: Terminals adapted for prismatic, pouch or rectangular cells - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - Y10T 29/49108: Electric battery cell making - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC 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 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electric storage device includes: a rolled electrode assembly 10 formed by winding a positive electrode, a negative electrode, and a separator so as to have curved portions and linear portions; current collectors 7; and an electrolyte solution 3. A positive electrode substrate has at one end 10A an unformed portion 11E formed without a positive electrode mixture layer, and a negative electrode substrate has at the other end 10B an unformed portion 13E formed without a negative electrode mixture layer. The current collectors 7 are connected respectively to at least part of the linear portions in the unformed portion of the positive electrode at the one end 10A and that of the negative electrode at the other end 10B. The one end 10A in the positive electrode has a length greater than the winding length, and/or the other end 10B in the negative electrode has such a length. ## Claims ### Claim 1 An electric storage device comprising: a housing; an electrode assembly in roll form housed in the housing, the electrode assembly being formed by winding a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode so as to have curved portions and linear portions continuous with the curved portions; current collectors housed in the housing, the current collectors being connected respectively to the positive electrode at one end in a direction of a winding axis of the electrode assembly and to the negative electrode at the other end in the direction of the winding axis of the electrode assembly; and an electrolyte solution housed in the housing, wherein the positive electrode includes a positive electrode substrate and a positive electrode mixture layer formed on the positive electrode substrate in a region excluding one end of the positive electrode substrate, the negative electrode includes a negative electrode substrate and a negative electrode mixture layer formed on the negative electrode substrate in a region excluding the other end of the negative electrode substrate, the positive electrode substrate has at its one end an unformed portion in which the positive electrode mixture layer is not formed, the negative electrode substrate has at its other end an unformed portion in which the negative electrode mixture layer is not formed, the current collectors are connected respectively to at least part of the linear portions in the unformed portion of the positive electrode at the one end and to at least part of the linear portions in the unformed portion of the negative electrode at the other end, and the one end in the positive electrode has a length greater than the winding length, and/or the other end in the negative electrode has a length greater than the winding length. ### Claim 2 (depends on 1) The electric storage device according to claim 1, wherein in the positive electrode, the one end is arcuate so as to be concave toward the other end, and/or in the negative electrode, the other end is arcuate so as to be concave toward the one end. ### Claim 3 (depends on 1) The electric storage device according to claim 1, wherein a ratio in the positive electrode substrate and/or the negative electrode substrate of a warpage, as measured per meter in a direction orthogonal to the winding axis, with respect to a width in the direction of the winding axis is at least 0.03 but not more than 0.10. ### Claim 4 (depends on 1) An electric storage system comprising: the electric storage device according to claim 1; and a control unit configured to control charge and discharge of the electric storage device. ### Claim 5 A method for producing an electric storage device, comprising: a step of preparing a positive electrode including a positive electrode substrate and a positive electrode mixture layer formed on the positive electrode substrate in a region excluding one end edge in a winding direction of the positive electrode substrate; a step of preparing a negative electrode including a negative electrode substrate and a negative electrode mixture layer formed on the negative electrode substrate in a region excluding the other end edge in the winding direction of the negative electrode substrate; a step of forming an electrode assembly in roll form having curved portions and linear portions continuous with the curved portions by winding the positive electrode and the negative electrode with an separator interposed therebetween; a step of forming current collectors so as to be connected respectively to the positive electrode at one end in a direction of a winding axis of the electrode assembly and to the negative electrode at the other end in the direction of the winding axis of the electrode assembly; and a step of housing the electrode assembly, the current collectors, and the electrolyte solution into the housing, wherein in the step of forming the electrode assembly, the winding is performed so that an unformed portion, formed at the one end edge of the positive electrode substrate, in which the positive electrode mixture layer is not formed is located at the one end, and an unformed portion, formed at the other end edge of the negative electrode substrate, in which the negative electrode mixture layer is not formed is located at the other end, in the step of forming the current collectors, the current collectors are formed so as to be connected respectively to at least part of the linear portions in the unformed portion of the positive electrode substrate at the one end and to at least part of the linear portions in the unformed portion of the negative electrode substrate at the other end, and in the step of preparing the positive electrode, the positive electrode in which the one end edge has a length greater than the winding length is prepared, and/or in the step of preparing the negative electrode, the negative electrode in which the other end edge has a length greater than the winding length is prepared. ### Claim 6 (depends on 5) The method for producing an electric storage device according to claim 5, wherein in the step of preparing the positive electrode, the positive electrode substrate in which the one end edge in the unformed portion is arcuate so as to be concave toward the other end edge on the opposite side of the unformed portion is used, and/or in the step of preparing the negative electrode, the negative electrode substrate in which the other end edge in the unformed portion is arcuate so as to be concave toward the one end edge on the opposite side of the unformed portion is used. ### Claim 7 (depends on 5) The method for producing an electric storage device according to claim 5, wherein in the step of preparing the positive electrode and/or the step of preparing the negative electrode, a ratio in the positive electrode substrate and/or the negative electrode substrate of a warpage, as measured per meter in a direction orthogonal to the winding axis, with respect to a width in the direction of the winding axis is at least 0.03 but not more than 0.10. ### Claim 8 (depends on 5) A method for producing an electric storage system, comprising: a step of producing an electric storage device using the method for producing an electric storage device according to claim 5; and a step of forming a control unit configured to control charge and discharge of the electric storage device.