# US 12,113,174 B2 · Method for manufacturing lithium-ion cell and lithium-ion cell > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,174 B2 - Document ID: US12113174B2 - Status: Granted - Kind: B2 - Application number: 17/282,148 - Filed: 2019-10-01 - Published: 2021-11-18 - Granted: 2024-10-08 - Earliest claimed: 2018-10-02 - Assignees: Eliiy Power Co., Ltd. - Applicants: ELIIY Power Co., Ltd. - Inventors: Ryota Furuya; Tomitaro Hara - Web page: https://patentgrep.com/patent/US12113174B2 ## CPC - H01M 4/139: Processes of manufacture - H01M 10/0568: characterised by the solutes - H01M 4/0416: {involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence)} - H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers - 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 10/0583: of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2300/0025: Organic electrolyte - H01M 2300/0045: Room temperature molten salts comprising at least one organic ion - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - 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 method of the present invention for manufacturing a lithium-ion cell comprises the step of impregnating a porous positive-electrode active material layer or a porous negative-electrode active material layer with an ionic liquid electrolyte. The ionic liquid electrolyte includes: an ionic liquid comprising an anion and a cation; and a lithium salt dissolved in the ionic liquid. The anion is bis(fluorosulfonyl)imide ion. The lithium salt is lithium bis(fluorosulfonyl)imide or lithium bis(trifluoromethansulfonyl)imide. The ionic liquid electrolyte contains the lithium salt at a concentration of 1.6 mol/L to 3.2 mol/L inclusive. The step of impregnation with the ionic liquid electrolyte is the step of impregnating the positive-electrode active material layer or the negative-electrode active material layer with the ionic liquid electrolyte at a temperature of 50° C. to 100° C. inclusive. ## Claims ### Claim 1 A method for manufacturing a lithium-ion cell, the method comprising a step of impregnating a porous positive-electrode active material layer or a porous negative-electrode active material layer with an ionic liquid electrolyte, wherein the ionic liquid electrolyte includes: an ionic liquid comprising an anion and a cation; and a lithium salt dissolved in the ionic liquid; the anion is bis (fluorosulfonyl) imide ion; the lithium salt is lithium bis (fluorosulfonyl) imide or lithium bis (trifluoromethansulfonyl) imide; the ionic liquid electrolyte contains the lithium salt at a concentration of 1.6 mol/L to 3.2 mol/L inclusive; and the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte at a temperature of 50° C. to 100° C. inclusive; and the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte having a viscosity of 50 mPa's or less. ### Claim 2 (depends on 1) The manufacturing method according to claim 1, wherein the step of impregnation with the ionic liquid electrolyte is carried out under reduced pressure. ### Claim 3 (depends on 1) The manufacturing method according to claim 1, wherein the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte without denaturing the ionic liquid electrolyte. ### Claim 4 (depends on 1) The manufacturing method according to claim 1, wherein the cation is pyrrolidinium-based ion or imidazolium-based ion. ### Claim 5 (depends on 4) The manufacturing method according to claim 4, wherein the cation is methylpropyl pyrrolidinium ion or ethylmethyl imidazolium ion. ### Claim 6 A method for manufacturing a lithium-ion cell, the method comprising a step of impregnating a porous positive-electrode active material layer or a porous negative-electrode active material layer with an ionic liquid electrolyte, wherein the ionic liquid electrolyte includes: an ionic liquid comprising an anion and a cation; and a lithium salt dissolved in the ionic liquid; the anion is bis (fluorosulfonyl) imide ion; the lithium salt is lithium bis (fluorosulfonyl) imide or lithium bis (trifluoromethansulfonyl) imide; the ionic liquid electrolyte contains the lithium salt at a concentration of 1.6 mol/L to 3.2 mol/L inclusive; and the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte at a temperature of 50° C. to 100° C. inclusive; and a logarithm differential pore volume distribution curve has a peak within a range of 0.6 μm or less of a pore diameter, the logarithm differential pore volume distribution curve showing a relationship between the pore diameter and a pore volume of pores in the porous positive-electrode active material layer or in the porous negative-electrode active material layer. ### Claim 7 (depends on 1) The manufacturing method according to claim 1, wherein the step of impregnation with the ionic liquid electrolyte is carried out in a state where an electrode assembly is placed in a cell housing, the electrode assembly comprising: a positive electrode including the porous positive-electrode active material layer; a negative electrode including the porous negative-electrode active material layer; and a separator. ### Claim 8 (depends on 2) The manufacturing method according to claim 2, wherein the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte without denaturing the ionic liquid electrolyte. ### Claim 9 A method for manufacturing a lithium-ion cell, the method comprising a step of impregnating a porous positive-electrode active material layer or a porous negative-electrode active material layer with an ionic liquid electrolyte, wherein the ionic liquid electrolyte includes: an ionic liquid comprising an anion and a cation; and a lithium salt dissolved in the ionic liquid; the anion is bis (fluorosulfonyl) imide ion; the lithium salt is lithium bis (fluorosulfonyl) imide or lithium bis (trifluoromethansulfonyl) imide; the ionic liquid electrolyte contains the lithium salt at a concentration of 1.6 mol/L to 3.2 mol/L inclusive; the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte at a temperature of 50°° C. to 100° C. inclusive; the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte without denaturing the ionic liquid electrolyte; and a logarithm differential pore volume distribution curve has a peak within a range of 0.6 μm or less of a pore diameter, the logarithm differential pore volume distribution curve showing a relationship between the pore diameter and a pore volume of pores in the porous positive-electrode active material layer or in the porous negative-electrode active material layer. ### Claim 10 (depends on 6) The manufacturing method according to claim 6, wherein the step of impregnation with the ionic liquid electrolyte is carried out in a state where an electrode assembly is placed in a cell housing, the electrode assembly comprising: a positive electrode including the porous positive-electrode active material layer; a negative electrode including the porous negative-electrode active material layer; and a separator. ### Claim 11 (depends on 9) The manufacturing method according to claim 9, wherein the step of impregnation with the ionic liquid electrolyte is carried out in a state where an electrode assembly is placed in a cell housing, the electrode assembly comprising: a positive electrode including the porous positive-electrode active material layer; a negative electrode including the porous negative-electrode active material layer; and a separator. ### Claim 12 (depends on 6) The manufacturing method according to claim 6, wherein the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte having a viscosity of 50 mPa's or less. ### Claim 13 (depends on 9) The manufacturing method according to claim 9, wherein the step of impregnation with the ionic liquid electrolyte is the step of impregnating the porous positive-electrode active material layer or the porous negative-electrode active material layer with the ionic liquid electrolyte having a viscosity of 50 mPa's or less. ### Claim 14 (depends on 13) The manufacturing method according to claim 13, wherein the step of impregnation with the ionic liquid electrolyte is carried out under reduced pressure. ### Claim 15 (depends on 6) The manufacturing method according to claim 6, wherein the step of impregnation with the ionic liquid electrolyte is carried out under reduced pressure. ### Claim 16 (depends on 9) The manufacturing method according to claim 9, wherein the step of impregnation with the ionic liquid electrolyte is carried out under reduced pressure. ### Claim 17 (depends on 6) The manufacturing method according to claim 6, wherein the cation is pyrrolidinium-based ion or imidazolium-based ion. ### Claim 18 (depends on 17) The manufacturing method according to claim 17, wherein the cation is methylpropyl pyrrolidinium ion or ethylmethyl imidazolium ion. ### Claim 19 (depends on 9) The manufacturing method according to claim 9, wherein the cation is pyrrolidinium-based ion or imidazolium-based ion. ### Claim 20 (depends on 19) The manufacturing method according to claim 19, wherein the cation is methylpropyl pyrrolidinium ion or ethylmethyl imidazolium ion.