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CN-122026007-A - Separator and battery

CN122026007ACN 122026007 ACN122026007 ACN 122026007ACN-122026007-A

Abstract

The embodiment of the application discloses a diaphragm and a battery, wherein the diaphragm is configured to be used by being matched with a gel electrolyte, the diaphragm comprises a base film and a ceramic layer, the porosity of the base film is more than or equal to 15%, the average pore diameter of a first through hole is more than or equal to 25nm, a molecular chain of the gel electrolyte can effectively pass through the first through hole to form a continuous ion transmission channel through the requirement on the porosity and the average pore diameter, meanwhile, in the formation process of the gel electrolyte, part of monomers of the gel electrolyte can react with residual groups in a coupling agent, the composite effect between the diaphragm and the gel electrolyte and a pole piece is effectively improved, the electrode expansion in the circulation process is restrained, and the battery performance of subsequent application is ensured.

Inventors

  • QIU BO
  • LIN YIMING
  • Yuan Taiyan
  • FENG BIAO
  • BU FANG

Assignees

  • 惠州亿纬锂能股份有限公司

Dates

Publication Date
20260512
Application Date
20251231

Claims (10)

  1. 1. A separator configured to adapt for use with a gel electrolyte; The diaphragm comprises a base film and a ceramic layer, wherein the ceramic layer is arranged on at least one side of the base film; wherein the base film has a first through hole having an average pore diameter of 25nm or more and a porosity of 15% or more; the ceramic layer comprises a ceramic material modified by a coupling agent.
  2. 2. A diaphragm according to claim 1, The first through holes have an average pore diameter of 25nm or more and 90nm or less, and/or The porosity of the base film has a value range of 15% or more and 85% or less.
  3. 3. A diaphragm according to claim 2, The average pore diameter of the first through holes is more than or equal to 45nm and less than or equal to 90nm; The porosity of the base film has a value range of 40% or more and 80% or less.
  4. 4. A diaphragm according to claim 1, The ceramic material comprises at least one of alumina, boehmite, silica, titanium dioxide, lithium aluminum titanium phosphate, lithium lanthanum titanium oxide, and/or The coupling agent comprises a silane coupling agent; Preferably, the silane coupling agent comprises at least one of KH-550, KH-560, KH-570, KH-792, GR-SI151, GR-SI171, GR-SI 172.
  5. 5. The membrane according to any one of claim 1 to 4, The separator satisfies at least one of the following conditions: The thickness of the separator is 3 μm to 35 μm, preferably 7 μm to 20 μm; the tensile strength of the diaphragm is more than or equal to 700MPa; the puncture strength of the septum is 300Kgf or more, and preferably 500Kgf or more.
  6. 6. A battery comprising a pole piece, a separator according to any one of claims 1 to 5, and a gel electrolyte.
  7. 7. The battery of claim 6, wherein the gel electrolyte is formed from a precursor comprising a lithium salt, an organic solvent, an additive, and a gel monomer via polymerization; the gel monomer comprises at least one of acrylic ester monomer, epoxy monomer and amine monomer; preferably, the acrylic monomer comprises at least one of methacrylate, polyol acrylic ester and acrylic ester containing special functional groups, and/or The epoxy monomer comprises glycidyl ether monomer, and/or The amine monomer comprises alkylamine or arylamine.
  8. 8. The battery of claim 6, wherein the battery is configured to provide the battery with a battery cell, The gel electrolyte is prepared by the following method: Mixing lithium salt, an organic solvent, an additive and a gel monomer to prepare a precursor; and injecting the precursor into a battery cell, standing, and heating and curing to obtain the gel electrolyte.
  9. 9. The battery of claim 6, wherein the battery is configured to provide the battery with a battery cell, The pole piece comprises a positive pole piece, the positive pole piece comprises at least one of nickel cobalt lithium manganate, lithium cobaltate and lithium iron phosphate, and/or The pole piece comprises a negative pole piece, and the negative pole piece comprises at least one of graphite and silicon-based negative pole materials.
  10. 10. The battery of claim 6, wherein the battery is configured to provide the battery with a battery cell, The stripping force between the pole piece and the diaphragm is greater than or equal to 0.3N, and/or The passing rate of the battery in a hot box test is more than 30/50, and/or The battery has a passing rate of 30/50 or more in a needling test, and/or The battery has a discharge capacity retention rate of 99% or more at 1C rate, 90% or more at 3C rate, 85% or more at 5C rate, 75% or more at 7C rate, 65% or more at 10C rate, and/or The number of cycles of the battery to 80% initial capacity at 1C charge-discharge rate required at least 450 weeks.

Description

Separator and battery Technical Field The application relates to the technical field of batteries, in particular to a diaphragm and a battery. Background Solid-state batteries have intrinsic safety characteristics, and many battery enterprises are devoted to research and development of solid-state battery technologies. Currently, the main technical routes are divided into three directions, sulfide electrolyte, oxide electrolyte and polymer electrolyte. However, in the preparation of solid-state batteries, the wettability of the separator with electrolyte is inferior to that of liquid electrolyte, and thus, a targeted improvement of the separator is required. Disclosure of Invention The application provides a diaphragm and a battery, and aims to solve the problem that the existing electrolyte is poor in wettability to the diaphragm. The present application provides a separator configured to adapt for use with a gel electrolyte; The diaphragm comprises a base film and a ceramic layer, wherein the ceramic layer is arranged on at least one side of the base film; wherein the base film has a first through hole having an average pore diameter of 25nm or more and a porosity of 15% or more; the ceramic layer comprises a ceramic material modified by a coupling agent. Optionally, in some embodiments of the application, the first via has an average pore size of greater than or equal to 25nm and less than or equal to 90nm, and/or The porosity of the base film has a value range of 15% or more and 85% or less. Optionally, in some embodiments of the present application, an average pore size of the first through hole is greater than or equal to 45nm and less than or equal to 90nm; The porosity of the base film has a value range of 40% or more and 80% or less. Optionally, in some embodiments of the application, the ceramic material comprises at least one of alumina, boehmite, silica, titania, lithium aluminum titanium phosphate, lithium lanthanum titanyl, and/or The coupling agent comprises a silane coupling agent; Preferably, the silane coupling agent comprises at least one of KH-550, KH-560, KH-570, KH-792, GR-SI151, GR-SI171, GR-SI 172. Optionally, in some embodiments of the application, the separator satisfies at least one of the following conditions: The thickness of the separator is 3 μm to 35 μm, preferably 7 μm to 20 μm; the tensile strength of the diaphragm is more than or equal to 700MPa; the puncture strength of the septum is 300Kgf or more, and preferably 500Kgf or more. Accordingly, the present application also provides a battery comprising a pole piece, a separator as described above and a gel electrolyte. Alternatively, in some embodiments of the application, the gel electrolyte comprises a lithium salt, an organic solvent, an additive, and a gel monomer; the gel monomer comprises at least one of acrylic ester monomer, epoxy monomer and amine monomer; preferably, the acrylic monomer comprises at least one of methacrylate, polyol acrylic ester and acrylic ester containing special functional groups, and/or The epoxy monomer comprises glycidyl ether monomer, and/or The amine monomer comprises alkylamine or arylamine. Alternatively, in some embodiments of the application, the gel electrolyte is prepared using the following method: Mixing lithium salt, an organic solvent, an additive and a gel monomer to prepare a precursor; and injecting the precursor into a battery cell, standing, and heating and curing to obtain the gel electrolyte. Optionally, in some embodiments of the application, the pole piece comprises a positive pole piece comprising at least one of lithium nickel cobalt manganese oxide, lithium cobalt oxide, lithium iron phosphate, and/or The pole piece comprises a negative pole piece, and the negative pole piece comprises at least one of graphite and silicon-based negative pole materials. Optionally, in some embodiments of the application, the peel force of the pole piece from the diaphragm ranges from greater than or equal to 0.3N, and/or The passing rate of the battery in a hot box test is more than 30/50, and/or The battery has a passing rate of 30/50 or more in a needling test, and/or The battery has a discharge capacity retention rate of 99% or more at 1C rate, 90% or more at 3C rate, 85% or more at 5C rate, 75% or more at 7C rate, 65% or more at 10C rate, and/or The number of cycles of the battery to 80% initial capacity at 1C charge-discharge rate required at least 450 weeks. The diaphragm comprises a base film and a ceramic layer, wherein the porosity of the base film is more than or equal to 15%, the average pore diameter of the first through hole is more than or equal to 25nm, molecular chains of gel electrolyte can effectively penetrate through the first through hole to form a continuous ion transmission channel through the requirement on the porosity and the average pore diameter, meanwhile, partial monomers of the gel electrolyte can react with residual groups in a coupling agent in the for