# US 6,294,292 B1 · Secondary power source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,294,292 B1 - Document ID: US6294292B1 - Status: Granted - Kind: B1 - Application number: 09/353,136 - Filed: 1999-07-14 - Granted: 2001-09-25 - Earliest claimed: 1998-07-14 - Assignees: Asahi Glass Company, Limited - Inventors: Manabu Tsushima; Takeshi Morimoto; Yong Che - Web page: https://patentgrep.com/patent/US6294292B1 ## CPC - H01M 10/0569: characterised by the solvents - H01G 11/06: with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC] - H01G 11/28: arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives - H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx - H01M 4/364: {as mixtures} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy - H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy - H01M 4/587: for inserting or intercalating light metals - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2010/4292: {Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode} - Y02E 60/10: Energy storage using batteries - Y02E 60/13: Energy storage using capacitors - 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 ## Abstract A secondary power source, which comprises a positive electrode containing activated carbon, a negative electrode containing a carbon material capable of doping and undoping lithium ions, and an organic electrolyte containing a lithium salt, wherein the ratio of the positive electrode capacity (C+) to the negative electrode capacity (C−), i.e. C+/C−, is from 0.1 to 1.2. ## Claims ### Claim 1 A secondary power source, which comprises a positive electrode containing activated carbon, a negative electrode containing a carbon material capable of doping and undoping lithium ions, and an organic electrolyte containing a lithium salt, wherein a ratio of the positive electrode capacity (C+) to the negative electrode capacity (C−), i.e. C+/C−, is from 0.1 to 1.2, the positive electrode has a thickness of from 100 to 200 μm, and the negative electrode has a thickness of from 10 to 50 μm. ### Claim 2 (depends on 1) The secondary power source according to claim 1, wherein each of the positive electrode and the negative electrode is an electrode in a form of a layer formed on a current collector, and a thickness of the negative electrode is from 7 to 60% of a thickness of the positive electrode. ### Claim 3 (depends on 1) The secondary power source according to claim 1, wherein the carbon material has a lattice spacing of [002] face of from 0.335 to 0.410 nm. ### Claim 4 (depends on 3) The secondary power source according to claim 3, wherein the carbon material is natural graphite having a lattice spacing of [002] face of from 0.335 to 0.337 nm, or a carbon material obtained by subjecting a carbon material which is easily graphitized to heat treatment at a temperature of at least 2,800° C. ### Claim 5 (depends on 1) The secondary power source according to claim 1, wherein the solvent of the organic electrolyte comprises at least one member selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, sulfolane and dimethoxyethane. ### Claim 6 (depends on 1) The secondary power source according to claim 1, wherein the organic electrolyte contains at least 50 wt % of propylene carbonate and from 0.1 to 10 wt % of a crown ether. ### Claim 7 (depends on 1) The secondary power source according to claim 1, wherein the activated carbon of the positive electrode has a specific surface area of from 800 to 3,000 m2/g. ### Claim 8 (depends on 7) The secondary power source according to claims 7, wherein the activated carbon of the positive electrode is steam-activated coconut shell type activated carbon or steam-activated phenol resin type activated carbon. ### Claim 9 (depends on 1) The secondary power source according to claim 1, wherein the positive electrode contains from 0.1 to 20 wt % of a conductive material. ### Claim 10 (depends on 1) The secondary power source according to claim 1, wherein the positive electrode contains a lithium transition metal oxide in an amount of from 0.1 to 20 wt %. ### Claim 11 (depends on 10) The secondary power source according to claim 10, wherein the lithium transition metal oxide is a compound of lithium and at least one member selected from the group consisting of V, Mn, Fe, Co, Ni, Zn and W. ### Claim 12 (depends on 10) The secondary power source according to claim 10, wherein the lithium transition metal oxide is LixCoyNi1−yO2 or LizMn2O4, wherein 0