# US 8,465,874 B2 · Lithium-ion secondary battery 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 8,465,874 B2 - Document ID: US8465874B2 - Status: Granted - Kind: B2 - Application number: 11/398,638 - Filed: 2006-04-06 - Published: 2007-01-04 - Granted: 2013-06-18 - Earliest claimed: 2005-04-07 - Assignees: Sharp Kabushiki Kaisha - Applicants: Naoto Nishimura; Motoaki Nishijima; Shinsuke Kobayashi - Inventors: Naoto Nishimura; Motoaki Nishijima; Shinsuke Kobayashi - Web page: https://patentgrep.com/patent/US8465874B2 ## CPC - H01M 4/806: {Nonwoven fibrous fabric containing only fibres} - H01M 4/0404: {by coating on electrode collectors} - H01M 4/0416: {involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence)} - H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis} - H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx - H01M 4/364: {as mixtures} - H01M 4/587: for inserting or intercalating light metals - H01M 10/052: Li-accumulators - H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)} - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2004/027: {Negative electrodes} - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y10T 29/49108: Electric battery cell making - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract In a lithium-ion secondary battery of the present invention, the electrical resistivity of the mixture of a positive electrode active material, an electrically conductive member, and a binder is 0.1 Ωcm or more but 1 Ωcm or less. The positive and negative electrodes each have an electrical capacity of 10 mAh or more but 50 mAh or less per volume of a rectangular parallelepiped that has a 1 cm2 square base on a face of the electrode of one polarity facing the electrode of the other polarity and that has a height equal to the thickness of the electrode of the one polarity at the square base. Used as the negative electrode thereof is a negative electrode formed by sintering graphite powder, non-graphitizing carbon, and fibrous powder retained in the pores of a porous metal structure in an inert gas atmosphere at a temperature of between 600 and 1000° C. ## Claims ### Claim 1 A lithium-ion secondary battery having a battery capacity of 5 Ah or more, the lithium-ion secondary battery comprising: a positive electrode comprising a positive electrode active material, a first electrically conductive member, a first binder, and a first charge collecting member; a negative electrode comprising a negative electrode active material, a second electrically conductive member, a second binder, and a second charge collecting member; and an electrolyte containing an electrolytic salt, wherein an electrical resistivity of a mixture of the positive electrode active material, the first electrically conductive member, and the first binder is 0.1 Ωcm or more but 1 Ωcm or less, the positive and negative electrodes each have an electrical capacity of 10 mAh or more but 50 mAh or less per volume of a rectangular parallelepiped that has a 1 cm2 square base on a face of the electrode of one polarity facing the electrode of the other polarity and that has a height equal to a thickness of the electrode of the one polarity at the square base, a capacity ratio of the negative electrode to the positive electrode is 1 or more but 1.5 or less, and the negative electrode is formed by sintering negative electrode ingredients including graphite powder, non-graphitizing carbon, and fibrous powder in pores of a porous metal structure used as the second charge collecting member. ### Claim 2 (depends on 1) The lithium-ion secondary battery of claim 1, wherein a porosity of the porous metal structure is 75% or more but 98% or less. ### Claim 3 (depends on 1) The lithium-ion secondary battery of claim 1, wherein the porous metal structure is formed of a material selected from the group consisting of iron, cobalt, nickel, and an alloy thereof. ### Claim 4 (depends on 3) The lithium-ion secondary battery of claim 3, wherein the porous metal structure is nickel foam. ### Claim 5 (depends on 1) The lithium-ion secondary battery of claim 1, wherein the non-graphitizing carbon is a carboxymethylcellulose polymer or a polymer of carboxymethylcellulose derivative. ### Claim 6 (depends on 1) The lithium-ion secondary battery of claim 1, wherein the fibrous powder is powder of highly graphitized carbon fiber. ### Claim 7 (depends on 1) The lithium-ion secondary battery of claim 1, wherein a fiber diameter of the fibrous powder is between 0.1 and 80 μm. ### Claim 8 (depends on 1) The lithium-ion secondary battery of claim 1, wherein the graphite powder exhibits, when subjected to wide-angle X-ray diffractometry, an average interplanar spacing of (002) plane of between 0.335 and 0.340 nm, a crystallite thickness in (002) plane direction of 10 nm or more, and a crystallite thickness in (110) plane direction of 10 nm or more. ### Claim 9 (depends on 1) The lithium-ion secondary battery of claim 1, wherein a particle size of the graphite powder is not more than 80 μm. ### Claim 10 (depends on 1) The lithium-ion secondary battery of claim 1, wherein a sintering temperature of the negative electrode is between 600 and 1000° C. ### Claim 11 (depends on 1) The lithium-ion secondary battery of claim 1, wherein the graphite has an R value of 0.4 or less. ### Claim 12 A lithium-ion secondary battery having a battery capacity of 5 Ah or more, the lithium-ion secondary battery comprising: a positive electrode comprising a positive electrode active material, a first electrically conductive member, a first binder, and a first charge collecting member; a negative electrode comprising a negative electrode active material, a second electrically conductive member, a second binder, and a second charge collecting member; and an electrolyte containing an electrolytic salt, wherein an electrical resistivity of a mixture of the positive electrode active material, the first electrically conductive member, and the first binder is 0.1 Ωcm or more but 1 Ωcm or less, the positive and negative electrodes each have an electrical capacity of 10 mAh or more but 50 mAh or less per volume of a rectangular parallelepiped that has a 1 cm2 square base on a face of the electrode of one polarity facing the electrode of the other polarity and that has a height equal to a thickness of the electrode of the one polarity at the square base, a capacity ratio of the negative electrode to the positive electrode is 1 or more but 1.5 or less, and the negative electrode is formed by sintering negative electrode ingredients including graphite powder, non-graphitizing carbon, and fibrous powder in pores of a porous metal structure used as the second charge collecting member and wherein the graphite has an R value of 0. ### Claim 13 (depends on 12) The lithium-ion secondary battery of claim 12, wherein a porosity of the porous metal structure is 75% or more but 98% or less. ### Claim 14 (depends on 12) The lithium-ion secondary battery of claim 12, wherein the porous metal structure is formed of a material selected from the group consisting of iron, cobalt, nickel, and an alloy thereof. ### Claim 15 (depends on 14) The lithium-ion secondary battery of claim 14, wherein the porous metal structure is nickel foam. ### Claim 16 (depends on 12) The lithium-ion secondary battery of claim 12, wherein the non-graphitizing carbon is a carboxymethylcellulose polymer or a polymer of carboxymethylcellulose derivative. ### Claim 17 (depends on 12) The lithium-ion secondary battery of claim 12, wherein the fibrous powder is powder of highly graphitized carbon fiber. ### Claim 18 (depends on 12) The lithium-ion secondary battery of claim 12, wherein a fiber diameter of the fibrous powder is between 0.1 and 80 μm. ### Claim 19 (depends on 12) The lithium-ion secondary battery of claim 12, wherein the graphite powder exhibits, when subjected to wide-angle X-ray diffractometry, an average interplanar spacing of (002) plane of between 0.335 and 0.340 nm, a crystallite thickness in (002) plane direction of 10 nm or more, and a crystallite thickness in (110) plane direction of 10 nm or more. ### Claim 20 (depends on 12) The lithium-ion secondary battery of claim 12, wherein a particle size of the graphite powder is not more than 80 μm. ### Claim 21 (depends on 12) The lithium-ion secondary battery of claim 12, wherein a sintering temperature of the negative electrode is between 600 and 1000° C.