# US 10,319,986 B2 · Positive electrode for nonaqueous electrolyte secondary batteries and nonaqueous electrolyte secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,319,986 B2 - Document ID: US10319986B2 - Status: Granted - Kind: B2 - Application number: 15/525,353 - Filed: 2015-11-18 - Published: 2017-11-09 - Granted: 2019-06-11 - Earliest claimed: 2014-11-28 - Assignees: Sanyo Electric Co., Ltd. - Applicants: Sanyo Electric Co., Ltd. - Inventors: Kouhei Tuduki; Atsushi Fukui - Web page: https://patentgrep.com/patent/US10319986B2 ## CPC - H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 4/366: {as layered products} - 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 4/628: {Inhibitors, e.g. gassing inhibitors, corrosion inhibitors} - H01M 4/0404: {by coating on electrode collectors} - H01M 4/1391: of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 10/052: Li-accumulators - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2004/028: {Positive electrodes} - Y02E 60/10: Energy storage using batteries - 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 ## Abstract A positive electrode for nonaqueous electrolyte secondary batteries includes a positive electrode current collector and a positive electrode mix layer, formed on the current collector, containing a positive electrode active material. The positive electrode active material mainly contains a lithium transition metal oxide in which the molar ratio of nickel (Ni) to a transition metal component is 20% or more. The positive electrode mix layer contains a plurality of pores and has a first peak of a logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where the pore diameter D is less than 1 μm and a second peak of the logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where the pore diameter D is 1 μm or more in a pore distribution determined by mercury intrusion porosimetry. According to this configuration, a nonaqueous electrolyte secondary battery having excellent output characteristics can be provided. ## Claims ### Claim 1 A positive electrode for nonaqueous electrolyte secondary batteries, comprising a positive electrode current collector and a positive electrode mix layer, formed on the current collector, containing a positive electrode active material, wherein the positive electrode active material mainly contains a lithium transition metal oxide in which the molar ratio of nickel (Ni) to a transition metal component is 20% or more and the positive electrode mix layer contains a plurality of pores and has a first peak of a logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where the pore diameter D is less than 1 μm and a second peak of the logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where the pore diameter D is 5 μm or more in a pore distribution determined by mercury intrusion porosimetry, wherein the plurality of pores corresponding to the second peak are regularly formed on a surface of the positive electrode mix layer. ### Claim 2 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the ratio (D2/D1) of a second mode diameter D2 corresponding to the second peak to a first mode diameter D1 corresponding to the first peak is fifty times or more. ### Claim 3 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein, in the lithium transition metal oxide, the molar ratio of nickel (Ni) to the transition metal component is 35% or more. ### Claim 4 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the maximum rate of change in cell volume of the lithium transition metal oxide at a charge cut-off potential between zero charge and 4.3 V (vs. Li/Li+) is 1.5% or less. ### Claim 5 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the lithium transition metal oxide contains tungsten (W). ### Claim 6 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the positive electrode mix layer contains at least one of a phosphate compound and a tungsten oxide. ### Claim 7 (depends on 1) A nonaqueous electrolyte secondary battery comprising: the positive electrode according claim 1; a negative electrode; and a nonaqueous electrolyte. ### Claim 8 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 1, wherein the second peak of the logarithmic differential pore volume distribution (dV/dlogD) appears in the range where the pore diameter D is 19 μm or more. ### Claim 9 (depends on 1) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 1, wherein the pores corresponding to the second peak are grooves. ### Claim 10 (depends on 9) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 9, wherein the grooves are formed at a substantially same interval. ### Claim 11 A positive electrode for nonaqueous electrolyte secondary batteries comprising a positive electrode current collector and a positive electrode mix layer formed on the positive electrode current collector, wherein the positive electrode mix layer includes: a plurality of positive electrode active material particles formed on the positive electrode current collector, a plurality of cavities, which are present between a certain particle of the positive electrode active material particles and other particles of the positive electrode active material particles contacting the certain particle, and which have a first peak of a logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where a diameter D of each of the plurality of cavities is less than 1 μm and, a plurality of pores, which have openings in a surface of the positive electrode mix layer, and which have a second peak of the logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where the diameter D of each of the plurality of pores is 5 μm or more, wherein the plurality of positive electrode active material particles mainly contains a lithium transition metal oxide in which the molar ratio of nickel (Ni) to a transition metal component is 20% or more. ### Claim 12 (depends on 11) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 11, wherein the diameter D of each of the plurality of cavities is smaller than a diameter of each of the plurality of positive electrode active material particles. ### Claim 13 A positive electrode for nonaqueous electrolyte secondary batteries comprising a positive electrode current collector and a positive electrode mix layer formed on the positive electrode current collector, wherein the positive electrode mix layer includes: a plurality of positive electrode active material particles formed on the positive electrode current collector, a plurality of cavities, which are present between a certain particle of the positive electrode active material particles and other particles of the positive electrode active material particles contacting the certain particle, and which have a first peak of a logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where a diameter D is less than 1 μm and, a plurality of grooves formed in the positive electrode mix layer, and which have a second peak of the logarithmic differential pore volume distribution (dV/dlogD) that appears in the range where the diameter D is 5 μm or more, wherein the plurality of positive electrode active material particles mainly contains a lithium transition metal oxide in which the molar ratio of nickel (Ni) to a transition metal component is 20% or more. ### Claim 14 (depends on 13) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 13, the diameter D of each of the plurality of cavities is smaller than a particle diameter of each of the plurality of positive electrode active material particle. ### Claim 15 (depends on 13) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 13, wherein each of the plurality of grooves have substantially a same width. ### Claim 16 (depends on 13) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 13, wherein each of the plurality of grooves extend in substantially the same direction. ### Claim 17 (depends on 13) The positive electrode for nonaqueous electrolyte secondary batteries according to claims 13, wherein the plurality of grooves are formed at substantially equal intervals.