# US 2017/0288259 A1 · Electricity storage device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0288259 A1 - Document ID: US20170288259A1 - Status: Published application - Kind: A1 - Application number: 15/512,206 - Filed: 2015-09-17 - Published: 2017-10-05 - Earliest claimed: 2014-09-22 - Assignees: Kabushiki Kaisha Toyota Jidoshokki - Applicants: Kabushiki Kaisha Toyota Jidoshokki - Inventors: Atsushi MINAGATA; Motoaki OKUDA - Web page: https://patentgrep.com/patent/US20170288259A1 ## CPC - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01G 11/26: characterised by their structure, e.g. multi-layered, porosity or surface features - H01G 11/52: Separators - H01M 4/0404: {by coating on electrode collectors} - H01M 10/0413: {Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes} - H01M 10/0463: {Cells or batteries with horizontal or inclined electrodes} - H01M 10/0468: {Compression means for stacks of electrodes and separators} - H01M 10/44: Methods for charging or discharging (circuits for charging H02J7/00) - H01M 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators - H01M 50/55: on the same side of the cell - H01M 2004/025: {with shapes other than plane or cylindrical} - H01M 2004/027: {Negative electrodes} - H01M 2004/028: {Positive electrodes} - Y02E 60/10: Energy storage using batteries - Y02E 60/13: Energy storage using capacitors - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10) - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract This electricity storage device is provided with an electrode assembly. The electrode assembly is constructed by laminating two electrodes of different polarities and a separator disposed between the electrodes with the electrodes being insulated from each other. Each of the electrodes has a metal foil and active material layers that are formed by coating an active material on the metal foil in a coating direction. The elongation rate of the separator varies in different directions, and the separator has a direction in which the elongation rate is higher than in the other directions. The higher elongation rate direction of the separator intersects the coating direction of the active material on at least one of the electrodes. ## Claims ### Claim 1 An electricity storage device comprising an electrode assembly, wherein electrodes that have different polarities from each other with a separator that insulates the electrodes from each other, each of the electrodes has a rectangular foil, an active material layer in which active material is arranged on the foil, and a tab protruding from a part of one side extending in a longitudinal direction of the foil, one end in the longitudinal direction of the electrode coincides with one end in the longitudinal direction of the active material layer, the other end in the longitudinal direction of the electrode coincides with the other end in the longitudinal direction of the active material layer, the active material has a constant coating direction, the separator has one direction in which the stretchability of the separator is higher than in the other directions, the coating direction of the active material in at least one of the electrodes is a direction along the protruding direction of the tab, and the direction of the high stretchability in the separator is orthogonal to the coating direction of the active material of at least one of the electrodes. ### Claim 2 (depends on 1) The electricity storage device according to claim 1, wherein one of the active material layers of the electrodes, which have different polarities, is harder than the other active material layer, and the direction of the high stretchability in the separator is orthogonal to the coating direction of the active material in the electrode having the harder active material layer. ### Claim 3 (depends on 1) The electricity storage device according to claim 1, wherein the direction of the high stretchability in the separator is orthogonal to the coating direction of the active material. ### Claim 4 (depends on 1) The electricity storage device according to claim 1, wherein the electricity storage device is a rechargeable battery. ### Claim 5 (depends on 1) The electricity storage device according to claim 1, wherein the separator is configured by biaxial stretching, in which separator material is stretched in two directions orthogonal to each other, and one of the two axes has higher stretchability than the stretchability of the other axis. ### Claim 6 An electricity storage device comprising an electrode assembly, wherein the electrode assembly is configured by stacking electrodes that have different polarities from each other with a separator that insulates the electrodes from each other, each of the electrodes has a rectangular foil, an active material layer in which active material is arranged on the foil, and a tab protruding from a part of one side extending in a longitudinal direction of the foil, one end in the longitudinal direction of the electrode coincides with one end in the longitudinal direction of the active material layer, the other end in the longitudinal direction of the electrode coincides with the other end in the longitudinal direction of the active material layer, the active material has a constant coating direction, the separator has one direction in which the stretchability of the separator is higher than in the other directions, the coating direction of the active material in at least one of the electrodes is a direction along the protruding direction of the tab, the direction of the high stretchability in the separator intersects the coating direction of the active material of at least one of the electrodes, the separator is one of a plurality of separators that constitutes the electrode assembly, and the separators are stacked such that the directions of the high stretchabilities coincide with each other. ### Claim 7 (depends on 6) The electricity storage device according to claim 6, wherein one of the active material layers of the electrodes, which have different polarities, is harder than the other active material layer, and the direction of the high stretchability in the separator intersects the coating direction of the active material in the electrode having the harder active material layer. ### Claim 8 (depends on 6) The electricity storage device according to claim 6, wherein the direction of the high stretchability in the separator is orthogonal to the coating direction of the active material. ### Claim 9 (depends on 6) The electricity storage device according to claim 6, wherein the separator is configured by biaxial stretching, in which separator material is stretched in two directions orthogonal to each other, and one of the two axes has higher stretchability than the stretchability of the other axis. ### Claim 10 (depends on 6) The electricity storage device according to claim 6, wherein the electricity storage device is a rechargeable battery.