A copper magnetic current collector and its preparation process and magnetic lithium-air battery containing it

Abstract

The invention relates to the field of lithium metal air batteries, in particular to a copper magnetic current collector, a preparation process thereof and a magnetic lithium air battery containing thesame. Surface modification is performed on a material with the permanent magnetic property to obtain a negative electrode material of a lithium air battery with large specific surface and high catalytic activity. According to the invention, the mass transfer process of oxygen is enhanced through the micro magnetic field, the concentration of active oxygen on the positive electrode surface is improved by the paramagnetic property of oxygen, the magnetohydrodynamics effect, the magnetization force effect and the like produce disturbance on the electrolyte, so that the reaction activity of the gas-liquid-solid three-phase interface is increased, the polarization is reduced, non-uniform deposition of the negative electrode metal lithium is improved, and the lithium dendrites are inhibited; the catalytic activity of the bifunctional catalyst is increased and the over-potential is reduced by the electric field generated by the copper layer structure; by the structure field energy, the volume change stress is released, the expansion space is provided, a uniform reaction active site and the like are provided, and the overall electrochemical performance is fully improved.

Description

technical field [0001] The invention relates to the field of lithium metal-air batteries, in particular to a copper magnetic current collector, a preparation process thereof, and a magnetic lithium-air battery containing the same. Background technique [0002] In recent years, metal-air batteries have become a research hotspot due to their light weight, non-toxicity, high efficiency, and low cost. This type of battery uses metals (zinc, lithium, aluminum, etc.) and oxygen as fuel to convert chemical energy into electrical energy. It is not only rich in cheap resources, but also renewable, and its structure is simpler than hydrogen fuel cells. Among them, lithium-air batteries have attracted much attention. It has the largest theoretical specific energy density of 11,430 Wh / kg, which is comparable to fossil fuels and 5 to 10 times that of traditional lithium-ion batteries. The negative electrode of the lithium-air battery uses lithium metal, and the active material of the po...

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Problems solved by technology

[0006] In order to solve the solid-liquid-gas three-phase reaction in the existing lithium-air battery, the discharge product is solid and non-conductive Li 2 o 2 , LiO 2 , so that the charge and discharge voltage deviates from the theoretical equilibrium position, resulting in a large overpotential; due to the discharge product Li 2 o 2 The continuous accumulation on the porous positive electrode blocks the pores and active sites, resulting in early termination of the discharge process and poor cycle performance; during the charge and discharge process, the uneven deposition of lithium leads to the formation of lithium dendrites and other problems. The present invention provides A copper magnetic current collector and its preparation process. The magnetic field generated by the prepared copper magnetic current collector induces lithium ion deposition, which can effectively inhibit the growth of dendrites and improve the cycle stability and safety performance of lithium batteries

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