# US 2013/0157121 A1 · Electrochemical cell > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157121 A1 - Document ID: US20130157121A1 - Status: Published application - Kind: A1 - Application number: 13/657,282 - Filed: 2012-10-22 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Seiko Instruments Inc. - Inventors: Tsuneaki TAMACHI; Ryo SATO; Shunji WATANABE; Maki OKUBO - Web page: https://patentgrep.com/patent/US20130157121A1 ## CPC - H01G 11/04: Hybrid capacitors - H01G 11/26: characterised by their structure, e.g. multi-layered, porosity or surface features - H01G 11/60: characterised by the solvent - H01G 11/80: Gaskets; Sealings - H01G 11/82: Fixing or assembling a capacitive element in a housing, e.g. mounting electrodes, current collectors or terminals in containers or encapsulations - H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence) - H01M 50/117: Inorganic material - H01M 50/15: for prismatic or rectangular cells (H01M50/153 takes precedence) - H01M 50/159: Metals - H01G 11/34: characterised by carbonisation or activation of carbon - H01M 10/0436: {Small-sized flat cells or batteries for portable equipment} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/0569: characterised by the solvents - H01M 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators - H01M 50/169: by welding, brazing or soldering - 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 - 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) - 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 high-quality electrochemical cell is provided that can suppress lowering of charge-discharge efficiency, and that can stably maintain the charge-discharge cycle characteristics over extended time periods. The electrochemical cell includes: a sealing container that includes a base member, and a lid member welded to the base member via a weld layer, the base member and the lid member sealing and defining a storage space in between: and a chargeable and dischargeable electrochemical element housed in the storage space and that includes a positive electrode, a negative electrode, and a separation member impregnated with a nonaqueous electrolytic solution the positive electrode is electrically connected to the base member. The negative electrode is electrically connected to the lid member by being overlaid on the positive electrode via the separation member, and allows cations and/or anions to move between the positive electrode and the negative electrode through the nonaqueous electrolytic solution. The lid member is formed of a metallic material that contains nickel. The negative elect ode has a greater capacitance than the positive electrode, ## Claims ### Claim 1 An electrochemical cell comprising: a sealing container that includes a base member and a lid member welded to the base member via a weld layer, the base member and the lid member sealing and defining a storage space in between: and a chargeable and dischargable electrochemical element housed in the storage space and that includes a positive electrode, a negative electrode, and a separation member impregnated with a nonaqueous electrolytic solution, wherein the positive electrode is electrically connected to the base member, wherein the negative electrode is electrically connected to the lid member by being overlaid en the positive electrode is the separation member, and allows cations and/or anions to move between the positive electrode and the negative electrode through the nonaqueous electrolytic solution, wherein the lid member is formed of a metallic material that contains nickel, and wherein the negative electrode has a greater capacitance than the positive electrode. ### Claim 2 (depends on 1) The electrochemical cell according to claim 1, wherein the capacitance of the negative electrode is greater than the capacitance of the positive electrode by a factor of from 1.13 to 2. ### Claim 3 (depends on 1) The electrochemical cell according to claim 1, wherein the negative electrode has a larger specific surface area than the positive electrode. ### Claim 4 (depends on 2) The electrochemical cell according to claim 2, wherein the negative electrode has a larger specific surface area than the positive electrode. ### Claim 5 (depends on 3) The electrochemical cell according to claim 3, wherein the positive electrode includes activated carbon subjected to a steam-activated surface treatment, and wherein the negative electrode includes activated carbon subjected to an alkali-activated surface treatment. ### Claim 6 (depends on 4) The electrochemical cell according to claim 4. wherein the positive electrode includes activated carbon subjected to a steam-activated surface treatment, and wherein the negative electrode includes activated carbon subjected to an alkali-activated surface treatment. ### Claim 7 (depends on 3) The electrochemical cell according to claim 3, wherein the negative electrode and the positive electrode include activated carbon of the same material subjected to the same surface treatment, and wherein the negative electrode has a smaller density than the positive electrode. ### Claim 8 (depends on 4) The electrochemical cell according to claim 4, wherein the negative electrode and the positive electrode include activated carbon of the same material subjected to the same surface treatment, and wherein the negative electrode has a smaller density than the positive electrode. ### Claim 9 (depends on 1) The electrochemical cell according to claim 1, wherein the nonaqueous electrolytic solution contains sulfone as a solvent. ### Claim 10 (depends on 9) The electrochemical cell according to claim 9, wherein the sulfone is a cyclic sulfone, and wherein the capacitance of the negative electrode is set to be greater than the capacitance of the positive electrode so that decomposition of the cyclic sulfone upon charging generates tetrahydrothiophene in 10 ppm or less. ### Claim 11 (depends on 2) The electrochemical cell according, to claim 2, wherein the nonaqueous electrolytic solution contains sulfone as a solvent. ### Claim 12 (depends on 11) The electrochemical cell according to claim 11, wherein the sulfone is a cyclic sulfone, and wherein the capacitance of the negative electrode is set to he greater than the capacitance of the positive electrode so that decomposition of the cyclic sulfone upon charging generates tetrahydrothiophene in 10 ppm or less. ### Claim 13 (depends on 3) The electrochemical cell according to claim 3, wherein the nonaqueous electrolytic solution contains sulfone as a solvent. ### Claim 14 (depends on 13) The electrochemical cell according to claim 13, wherein the sulfone is a cyclic sulfone, and wherein the capacitance of the negative electrode is set to be greater than the capacitance of the positive electrode so that decomposition of the cyclic sulfone upon charging generates tetrahydrothiophene in 10 ppm or less. ### Claim 15 (depends on 4) The electrochemical cell according to claim 4, wherein the nonaqueous electrolytic solution contains sulfone as a solvent. ### Claim 16 (depends on 15) The electrochemical cell according to claim 15, wherein the sulfone is a cyclic sulfone, and wherein the capacitance of the negative electrode is set to be greater than the capacitance of the positive electrode so that decomposition of the cyclic sulfone upon charging generates tetrahydrothiophene in 10 ppm or less. ### Claim 17 (depends on 5) The electrochemical cell according to claim 5, wherein the nonaqueous electrolytic solution contains sulfone as a solvent. ### Claim 18 (depends on 17) The electrochemical cell according to claim 17, wherein the sulfone is a cyclic sulfone, and wherein the capacitance of the negative electrode is set to be greater than the capacitance of the positive electrode so that decomposition of the cyclic sulfone upon charging generates tetrahydrothiophene in 10 ppm or less. ### Claim 19 (depends on 6) The electrochemical cell according to claim 6, wherein the nonaqueous electrolytic solution contain sulfone as a solvent. ### Claim 20 (depends on 19) The electrochemical cell according to claim 19, wherein the sulfone is a cyclic sulfone, and wherein the capacitance of the negative electrode is set to be greater than the capacitance of the positive electrode so that decomposition of the cyclic sulfone upon charging generates tetrahydrothiophene in 10 ppm or less.