A kind of negative pole piece and lithium metal battery

Abstract

The invention provides a negative pole piece and a lithium metal battery. The negative electrode sheet includes a negative electrode collector and a lithium metal negative electrode disposed on at least one surface of the negative electrode collector, and a polymer protective film is provided on the surface of the lithium metal negative electrode away from the negative electrode collector, and the polymer protective film includes lemon The acid copolymer, the number average molecular weight Mn of the citric acid copolymer is 10,000-1,000,000. The present invention can form a polymer protective film with high tensile strength, high puncture strength, high elongation, and high solid-liquid capacity on the surface of the lithium metal negative electrode in the negative pole piece, and the negative pole piece of the present invention is used for lithium metal two In secondary batteries, it can effectively slow down or even inhibit the growth of lithium dendrites, reduce the consumption of side reactions between electrolyte and lithium metal, improve the first charge and discharge Coulombic efficiency of lithium metal secondary batteries, and significantly improve the cycle stability of lithium metal secondary batteries and security.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a negative pole piece and a lithium metal battery. Background technique [0002] Lithium metal has a very high theoretical specific capacity: 3860mAh g -1 , the lowest reduction potential: -3.04V vs. standard hydrogen electrode, and low density: 0.534g cm -3 And other advantages, become the best choice for the anode material of the next generation of high specific energy secondary battery. However, the uncontrollable growth of lithium dendrites caused by the irregular deposition of lithium ions on the surface of the negative electrode has caused safety problems during the use of lithium metal batteries, which in turn restricts the wide application of lithium metal batteries. [0003] At present, many studies in the field of lithium metal batteries focus on adding functional additives to the electrolyte, such as vinylene carbonate, fluoroethylene carbonate, 2-methylfuran, and some alkal...

AI Technical Summary

Problems solved by technology

However, the problem of the above-mentioned prior art is that these protective films formed in situ have weak mechanical strength and incomplete coverage of metal lithium, which cannot completely prevent the severe SEI film caused by lithium metal morphology changes during lithium deposition / dissolution. , continuous recombination; the formation of lithium dendrites and the many problems that followed have not been substantially resolved

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