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CN-122025781-A - Solid-state battery and production method thereof

CN122025781ACN 122025781 ACN122025781 ACN 122025781ACN-122025781-A

Abstract

The invention relates to the technical field of solid-state batteries, and discloses a solid-state battery and a production method thereof. The solid-state battery comprises a positive electrode, a negative electrode and a solid-state electrolyte, wherein the solid-state electrolyte is formed by the reaction and solidification of components containing pentaerythritol tetraacrylate, lithium bistrifluoromethylsulfonyl imide, azodiisobutyronitrile, 3-acryloxypropyl trimethoxysilane and lithium chloride lithium thiophosphate. The production method comprises the steps of preparing precursor slurry from the electrolyte components, preparing composite positive electrode slurry by using the precursor slurry, sequentially coating the composite positive electrode slurry and the precursor slurry, covering a negative electrode to form a cell stack, and finally carrying out in-situ curing on the cell stack under the hot-pressing condition. The solid-phase interface with close contact is constructed through in-situ solidification, chemical bonding is realized by using the anchoring agent, interface impedance is effectively reduced, and the cycling stability of the solid-state battery is improved.

Inventors

  • LI GANG
  • LIU QIANG
  • QIAO BIN

Assignees

  • 深圳国颐科技发展有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (10)

  1. 1. A solid-state battery comprising a positive electrode, a negative electrode, and a solid-state electrolyte disposed between the positive electrode and the negative electrode; the solid electrolyte is prepared by reacting and curing the following components in parts by mass: 22.5-40 parts of pentaerythritol tetraacrylate; 1-5 parts of lithium bis (trifluoromethylsulfonyl) imide; 0.1-1 part of azodiisobutyronitrile; 0.2-2 parts of 3-acryloxypropyl trimethoxy silane; 59-70 parts of lithium chloride thiophosphate.
  2. 2. The solid-state battery according to claim 1, wherein the solid-state electrolyte is formed by reaction and curing of the following components in parts by mass: 32.5 parts of pentaerythritol tetraacrylate; 3 parts of lithium bis (trifluoromethylsulfonyl) imide; 0.5 part of azodiisobutyronitrile; 1 part of 3-acryloxypropyl trimethoxysilane; 64.5 parts of lithium chloride thiophosphate.
  3. 3. The solid-state battery according to claim 1, wherein the positive electrode is coated on an aluminum foil current collector, and comprises a composite positive electrode layer composed of the following components in parts by mass: 85-94 parts of nickel cobalt lithium manganate; 1-3 parts of acetylene black; 3-13 parts of anchored precursor slurry prepared by mixing pentaerythritol tetraacrylate, lithium bistrifluoromethylsulfonyl imide, azodiisobutyronitrile, 3-acryloxypropyl trimethoxysilane and lithium chloride lithium thiophosphate.
  4. 4. A solid state battery according to claim 1, wherein the thickness of the solid state electrolyte is 10-20 μm.
  5. 5. A solid state battery according to claim 3, wherein the composite positive electrode layer comprises the following components in parts by mass: 90 parts of nickel cobalt lithium manganate; 2 parts of acetylene black; 8 parts of anchoring precursor slurry.
  6. 6. A solid state battery according to claim 1, wherein the negative electrode is a lithium metal foil.
  7. 7. A method for producing a solid-state battery according to any one of claims 1 to 6, characterized by comprising the steps of: (a) Uniformly mixing pentaerythritol tetraacrylate, lithium bistrifluoromethylsulfonylimide, azodiisobutyronitrile, 3-acryloxypropyl trimethoxysilane and lithium chloride lithium thiophosphate to obtain an anchor-type precursor slurry; (b) Mixing nickel cobalt lithium manganate and acetylene black with the anchoring precursor slurry prepared in the step (a) to obtain composite anode slurry; (c) Coating the composite positive electrode slurry prepared in the step (b) on an aluminum foil current collector, then coating a layer of the anchoring precursor slurry prepared in the step (a), and finally covering a negative electrode to obtain a cell stack; (d) And (c) performing in-situ curing on the cell stack body prepared in the step (c) under the condition of applying heat and pressure to obtain the solid-state battery.
  8. 8. The method according to claim 7, wherein in step (d), the in-situ curing is performed under a pressure of 1 to 10MPa at a temperature of 60 to 85 ℃ for a constant temperature holding time of 1 to 3 hours.
  9. 9. The method of producing a solid-state battery according to claim 7, wherein in the step (a), the anchor-type precursor slurry is prepared by: Stirring pentaerythritol tetraacrylate, lithium bistrifluoromethylsulfonylimide, azodiisobutyronitrile and 3-acryloxypropyl trimethoxysilane at a low speed to obtain a premixed solution; Then adding lithium chloride thiophosphate to the pre-mixed solution, and stirring and defoaming for 30-90 minutes at a rotation speed of 1000-2000 rpm.
  10. 10. The method for producing a solid-state battery according to claim 7, wherein the composite positive electrode slurry is prepared by the steps of: carrying out dry premixing on nickel cobalt lithium manganate and acetylene black; then adding the anchoring precursor slurry into the dry pre-mixed material, and carrying out wet mixing for 30-60 minutes at the rotating speed of 800-1500 rpm.

Description

Solid-state battery and production method thereof Technical Field The invention relates to the technical field of solid-state batteries, in particular to a solid-state battery and a production method thereof. Background A solid-state battery is an electrochemical energy storage device that uses a solid-state electrolyte instead of a conventional liquid electrolyte. The solid-state battery has become an important development direction of the next-generation battery technology because the potential safety hazards of liquid leakage, inflammability and the like of the liquid electrolyte can be fundamentally solved in theory, and the solid-state battery is hopeful to match with a lithium metal negative electrode with high energy density. Currently, solid-state batteries are built mainly based on inorganic solid-state electrolytes or polymer solid-state electrolytes. In the technical route using inorganic electrolytes of high ionic conductivity such as sulfides, generally, an electrolyte powder is mixed with an electrode active material powder and then formed by high-pressure compression to construct an electrode and an electrolyte layer. The other method is to use polymer as matrix, mix polymer, lithium salt and filler into slurry by solvent method, and then to coat and form film, and then to carry out hot-press assembly. However, the above prior art still has drawbacks in achieving low interface impedance and long cycle stability. For the dry pressing process, it is difficult to form ideal physical contact between rigid inorganic particles, resulting in a large number of voids at the interface, resulting in higher ion transport resistance. The volume change of the electrode material further exacerbates this poor contact during the battery cycling and even leads to interface delamination, leading to rapid decay of the battery capacity. While the traditional solvent process can improve the partial contact problem, the residual solvent and weak physical combination between the polymer and the inorganic particles limit the further improvement of interface performance and structural stability. Therefore, the invention provides a solid-state battery and a production method thereof, which solve the defects in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a solid-state battery and a production method thereof, and solves the problems of high interface impedance and poor cycling stability caused by poor physical contact of a solid-phase interface and weak interface binding force in the traditional solid-state battery. In order to achieve the above purpose, the invention is realized by the following technical scheme: In a first aspect, the present invention provides a solid-state battery, which adopts the following technical scheme: A solid-state battery comprising a positive electrode, a negative electrode, and a solid-state electrolyte disposed between the positive and negative electrodes; the solid electrolyte is prepared by reacting and curing the following components in parts by mass: 22.5-40 parts of pentaerythritol tetraacrylate; 1-5 parts of lithium bis (trifluoromethylsulfonyl) imide; 0.1-1 part of azodiisobutyronitrile; 0.2-2 parts of 3-acryloxypropyl trimethoxy silane; 59-70 parts of lithium chloride thiophosphate. By adopting the technical scheme, the invention utilizes a liquid precursor system containing polymerizable monomers, inorganic solid electrolyte filler and difunctional interfacial anchoring agent to directly generate the organic-inorganic composite solid electrolyte in the battery in an in-situ thermal initiation polymerization mode. The technical effect is realized by the following mechanism: Interfacial anchoring mechanism: The 3-acryloxypropyl trimethoxysilane molecule contains two functional groups of different nature. The action principle is as follows: In the first step, chemical bonding with the inorganic phase. The trimethoxysilane group (-Si (OCH 3)3) of the molecule is hydrolyzed to form a silicon hydroxyl group (-Si (OH) 3) which is subjected to dehydration condensation reaction with lithium chloride thiophosphate and hydroxyl groups or other active sites on the surface of the positive electrode active material particles to form Si-O-M covalent bonds (M represents an inorganic particle surface element). And the second step is copolymerization with organic phase. The other end of the molecule is an acryloyloxy group which is used as a functional group capable of participating in free radical polymerization, and the acryloyloxy group is subjected to copolymerization reaction with pentaerythritol tetraacrylate which is a main polymerization monomer under the action of a thermal initiator to form a part of a crosslinked polymer network. Through the above steps, the interfacial anchoring agent establishes a covalent bond connection between the organic polymer matrix and the inorganic particulate filler, converting the two-phase interface