A high-strength ultra-light composite lithium band and a preparation method thereof are provided

Abstract

The invention relates to a high-strength ultra-light composite lithium band and a preparation method thereof, belonging to the technical field of preparation of negative electrode materials of lithiumbatteries. The composite lithium belt comprises a conductive framework and a metal lithium or a lithium alloy attached to the conductive framework; The conductive skeleton is a porous film formed byuniformly dispersing the conductive powder material in the polymer. At first, that polymer and the conductive pow material are melted and mix uniformly, the porous membrane is prepared by a dry double-pull method, and then a layer of ultra-thin metal lithium or lithium alloy is attached to the surface or the pores of the porous membrane by vacuum evaporation, electroplating or mechanical calendering to obtain a high-strength ultra-light composite lithium band. The invention has the advantages that the processing performance of the lithium belt can be improved and the energy density of the battery can be increased by using the composite lithium belt for the lithium primary battery and the lithium secondary battery. It is noteworthy that the metal lithium will not only adhere to the outer surface of the porous membrane, but also enter the pores of the porous membrane. This structure can greatly enhance the adhesion of lithium to the porous membrane and prevent lithium from falling off from the porous membrane.

Description

technical field [0001] The invention belongs to the technical field of lithium battery negative electrode material preparation, and in particular relates to a high-strength ultra-light composite lithium ribbon and a preparation method thereof. Background technique [0002] The theoretical specific capacity of metallic lithium is as high as 3860 mAh / g and the electrode potential is as low as -3.04V (compared to standard hydrogen electrodes). Using it as a negative electrode can significantly increase the energy density of lithium batteries. In a system that matches the current lithium-containing cathode materials, the lithium anode must be in excess, so reducing the amount of lithium anode can reduce the ineffective mass of the anode, thereby further improving the mass energy density of lithium metal batteries, so the lithium strip is ultra-thin has become a trend. However, due to the soft nature and low specific strength of lithium metal, the use of self-supporting ultra-th...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a high-strength ultra-light composite lithium strip and a preparation method thereof in order to solve the problems of low energy density of the existing battery weight and low reliability of the tab connection. The invention can improve the ultra-thin lithium strip Strength, improve the processing performance of the lithium strip and the reliability of the tab connection, while maintaining the advantages of the high weight and energy density of the battery brought about by the ultra-low density of metal lithium to the greatest extent

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