# US 10,770,759 B2 · Method of manufacturing lithium ion secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,759 B2 - Document ID: US10770759B2 - Status: Granted - Kind: B2 - Application number: 15/208,196 - Filed: 2016-07-12 - Published: 2017-01-19 - Granted: 2020-09-08 - Earliest claimed: 2015-07-17 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Takashi Miura; Masanori Kitayoshi - Web page: https://patentgrep.com/patent/US10770759B2 ## CPC - H01M 10/446: {Initial charging measures} - H01M 4/366: {as layered products} - H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/0567: characterised by the additives - H01M 10/0568: characterised by the solutes - H01M 10/0569: characterised by the solvents - H01M 10/0587: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators - H01M 2300/0034: Fluorinated solvents - 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 - 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 ## Abstract Provided is a method of manufacturing a lithium ion secondary battery. The method includes a step of initially charging the battery. The step includes: a first step of charging the battery such that a voltage Vt of the battery is increased to a first voltage Vh which is in a lower decomposition range Ad; a second step of holding the voltage Vt of the battery at the first voltage Vh; and a third step of charging the battery to a second voltage Ve, which is higher than the first voltage Vh, after the second step. ## Claims ### Claim 1 A method of manufacturing a lithium ion secondary battery, the lithium ion secondary battery including a positive electrode that includes a positive electrode active material layer containing positive electrode active material particles, a negative electrode, and a nonaqueous electrolytic solution that contains a compound containing fluorine, the positive electrode active material particles having a surface on which a film containing fluorine and phosphorus is formed, the positive electrode active material layer including particles of at least one of a metal phosphate and a metal pyrophosphate, and the method comprising: initially charging the lithium ion secondary battery, the initial charging including: a first step of charging the lithium ion secondary battery such that a voltage of the lithium ion secondary battery is increased to a first voltage which is in a lower decomposition range of the nonaqueous electrolytic solution; a second step of applying a voltage to the lithium ion secondary battery so as to hold the voltage of the lithium ion secondary battery at the first voltage for a predetermined holding period in a range of 10 to 90 minutes; and a third step of charging the lithium ion secondary battery to a second voltage, which is higher than the first voltage, after the second step, wherein negative electrode active material of the negative electrode includes graphite while the initial charging occurs. ### Claim 2 (depends on 1) The method according to claim 1, wherein in the third step, the lithium ion secondary battery is charged at a charge current which is higher than 1 C. ### Claim 3 (depends on 1) The method according to claim 1, wherein the predetermined holding period satisfies Rn=0.98Re to 1.02Re, in which Rn represents a battery resistance of a battery manufactured by performing the second step for the predetermined holding period and then performing the third step, and Re represents a battery resistance of a holding period extended battery manufactured by holding the first voltage not for the predetermined holding period but for an extended holding period, which is 1.5 times the predetermined holding period, and performing the third step. ### Claim 4 (depends on 1) The method according to claim 1, wherein the predetermined holding period satisfies Rn=0.99Re to 1.01Re, in which Rn represents a battery resistance of a battery manufactured by performing the second step for the predetermined holding period and then performing the third step, and Re represents a battery resistance of a holding period extended battery manufactured by holding the first voltage not for the predetermined holding period but for an extended holding period, which is 1.5 times the predetermined holding period, and performing the third step. ### Claim 5 (depends on 1) The method according to claim 1, wherein in the second step, the first voltage is held until a charge current of the lithium ion secondary battery becomes a predetermined cut-off current value or lower. ### Claim 6 (depends on 5) The method according to claim 5, wherein the predetermined cut-off current value is ⅖ of an end current value at an end stage of the first step. ### Claim 7 (depends on 5) The method according to claim 5, wherein an end current value at an end stage of the first step is 1 C or higher, and the predetermined cut-off current value is 0.05 C. ### Claim 8 (depends on 1) The method according to claim 1, wherein the particles of at least one of the metal phosphate and the metal pyrophosphate contained in the positive electrode active material layer have an average particle size of 1.5 μm or less. ### Claim 9 (depends on 1) The method according to claim 1, wherein in the first step and the third step, the lithium ion secondary battery is charged by constant-current charging at a predetermined current value of 3 C or higher. ### Claim 10 (depends on 1) The method according to claim 1, wherein the first step includes charging the lithium ion secondary battery by constant-current charging at a first predetermined current value, the third step includes charging the lithium ion secondary battery by constant-current charging at a second predetermined current value, and the first predetermined current value is the second predetermined current value or lower. ### Claim 11 A method of initially charging a lithium ion secondary battery, the lithium ion secondary battery including a positive electrode that includes a positive electrode active material layer containing positive electrode active material particles, a negative electrode, and a nonaqueous electrolytic solution that contains a compound containing fluorine, the positive electrode active material particles having a surface on which a film containing fluorine and phosphorus is formed, the positive electrode active material layer including particles of at least one of a metal phosphate and a metal pyrophosphate, and the method comprising: a first step of charging the lithium ion secondary battery such that a voltage of the lithium ion secondary battery is increased to a first voltage which is in a lower decomposition range of the nonaqueous electrolytic solution; a second step of applying a voltage to the lithium ion secondary battery so as to hold the voltage of the lithium ion secondary battery at the first voltage for a predetermined holding period in a range of 10 to 90 minutes; and a third step of charging the lithium ion secondary battery to a second voltage, which is higher than the first voltage, after the second step, wherein negative electrode active material of the negative electrode includes graphite while the initial charging occurs.