Lithium negative electrode protective film, preparation method and lithium metal secondary battery

Abstract

The invention relates to a lithium negative electrode protection film, a preparation method and a lithium metal secondary battery, belonging to the field of lithium metal secondary batteries. The lithium anode protective film is composed of lithium salt, ionic liquid, inorganic nanoparticles and lithium-treated Nafion polymer. Ionic liquids containing lithium salts are adsorbed on the surface of inorganic nanoparticles and uniformly dispersed in lithium-treated Nafion polymers. By arranging a mixed solution of lithium salts and ionic liquids; Mixing the mixed solution and the inorganic nanoparticles by sealed ball milling to obtain a quasi-solid electrolyte; The quasi-solid electrolyte is mixed with a lithium-treated Nafion polymer solution, coated on the surface of lithium or copper foil,and the protective film is prepared after the solvent is completely volatilized. As that lithium negative electrode protective film can inhibit the generation of lithium dendrite, the lithium negative electrode protective film has good mechanical properties and chemical stability, high lithium ionic conductivity and good film for performance; A lithium metal secondary battery provide with that lithium anode protective film has excellent electrochemical performance.

Description

Technical field [0001] The invention relates to a lithium negative electrode protective film, a preparation method and a lithium metal secondary battery, and belongs to the technical field of lithium metal secondary batteries. Background technique [0002] With the progress of society, the energy used by human beings is also increasing day by day. Efficient energy storage and conversion are the driving force of social progress, and the emergence and use of batteries enable people to use energy more efficiently and conveniently. At present, lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries and lithium-ion batteries have achieved commercial applications. Especially lithium-ion batteries have changed the way people communicate and transport. As the actual energy density of lithium-ion batteries (especially graphite anodes) is gradually approaching its theoretical limit, there is an urgent need for more efficient electrode materials to meet the development re...

AI Technical Summary

Problems solved by technology

[0003] However, there are still many problems in the direct use of metal lithium as the negative electrode material: the chemical nature of metal lithium is active, and it will react with air and water, resulting in difficulty in battery assembly; when charging, the deposited lithium will react with the electrolyte, resulting in low Coulombic efficiency; The uneven surface morphology of lithium leads to uneven surface charge distribution, which is easy to generate dendrites to pierce the separator and cause a short circuit of the battery, causing safety hazards

[0004] Although the above method suppresses the generation of metal lithium dendrites to a certain extent, it is subject to many limitations in the application process, such as the high cost of the method of Cui et al., the preparation of Li by Guo et al. 3 PO 4 The environmental conditions are harsh, and the modified SEI film formed by Yang et al. has poor mechanical properties, which is not conducive to the improvement of battery cycle life.

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