Battery diaphragm for solid-state lithium ion battery and preparation method of battery diaphragm

Abstract

The invention belongs to the technical field of preparation of lithium ion battery diaphragms, and particularly relates to a battery diaphragm for a solid-state lithium ion battery and a preparation method of the battery diaphragm. The battery diaphragm is prepared through steps as follows: preparation of an ethanol solution of ionic liquid polymers and an aromatic ketone ultraviolet cross-linking agent; ultraviolet cross-linking of polyimidazole salts and a polypropylene porous membrane; anionic recombination of the polyimidazole cross-linked polypropylene porous membrane; final drying for preparation of the battery diaphragm for the solid-state lithium ion battery. The overall performance of the ionic liquid polymers is enhanced by the aid of the polypropylene porous membrane, and a finished product of the battery diaphragm for the solid-state lithium ion battery better overcomes defects that an existing ionic liquid diaphragm is low in strength, difficult to form and prone to damage, has better strength and stability and has certain popularization and application value.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery diaphragm preparation, and in particular relates to a battery diaphragm for a solid-state lithium-ion battery and a preparation method thereof. Background technique [0002] All-solid-state lithium-ion batteries have the advantages of high safety performance, high energy density, and wide operating temperature range, and are an important direction for the development of lithium-ion batteries. In terms of safety, the flammable and explosive organic electrolyte is the key factor causing the safety problem of lithium-ion batteries. Abnormal conditions such as overcharging and internal short circuit may cause the liquid electrolyte to heat up, and there is a risk of spontaneous combustion or even explosion. The safety of all-solid-state batteries that replace organic electrolytes with solid-state electrolytes can be greatly improved. In addition, for all-solid-state batteries, since there...

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Problems solved by technology

[0007] Patent CN201110347022 discloses a method for preparing an ionic liquid gel electrolyte, adding a film-forming polymer to a mixed solvent formed by a solvent-non-solvent to prepare a uniform solution coating film and a white porous film; immersion preparation In the ionic liquid electrolyte, a solid electrolyte membrane is obtained. The electrochemical window of the membrane is greater than 5V, which has good electrical properties. However, because the ionic liquid is directly soaked and not fixed in the porous membrane, the electrolyte solution is lost during use;

[0008] Patent CN200810162187.X discloses a preparation method of high-strength ionic liquid gel, adding monomers, initiators, and cross-linking agents into ionic liquids for polymerization to obtain high-strength ionic liquid gels; the prepared high-strength ionic liquid gels Ionic liquid gel, the maximum compressive stress can reach 30MPa, to some extent overcome the shortcomings of low strength, fragility, poor processing and deformation performance of ionic liquid gel, but its strength is still lower than the existing battery separator (above 100MPa)

[0009] Based on the above research, although the performance or quality of solid-state lithium-ion batteries can be improved to a certain extent, in terms of actual production and preparation, it is still necessary to further study the electrolyte and battery separator of solid-state lithium-ion batteries in order to steadily improve and improve the performance of solid-state lithium-ion batteries. battery quality and improve its product performance