Research On The Electrochemical Performance Of Lithium-Zinc Alloy Anodes For Batteries

At present,the capacity of commercial lithium ion batteries is growing slowly,which is not enough to meet the needs of social production and living.Lithium metal is considered as the"Holy Grail"electrode because of its ultra-high theoretical capacity（3860 m Ah/g）and the most negative chemical potential（-3.04 V compared with standard hydrogen electrode）.However,during the cycle,it may cause problems such as uncontrollable lithium dendrite growth,which may lead to battery capacity decay,short circuit and even fire.Therefore,whether the problem of dendrite growth can be solved is the key to the commercialization of lithium metal anode.In this paper,lithium zinc alloy electrode was prepared by fusion of lithiophilic zinc metal and lithium metal by traditional hot melting method.Lithophilic zinc metal can reduce the nucleation overpotential of lithium,induce the uniform deposition of lithium ions on the surface of negative electrode,and effectively inhibit the formation of lithium dendrite.In addition,the lithium-zinc alloy can effectively alleviate the volume expansion in the process of charge and discharge,and improve the electrochemical performance and safety index of the battery.Through a series of electrochemical tests and morphology characterization,the properties of lithium zinc alloy anode and lithium metal anode were compared.The results show that the surface of the lithium zinc alloy synthesized by this method is smooth and the distribution of zinc element is uniform.Electrochemical test results show that the lithium zinc alloy symmetric battery with zinc content of 10 wt.%has very low overpotential and voltage polarization value in both carbonate and ether electrolytes,and the electrochemical cycling performance is the most outstanding.Compared with pure lithium metal,10 wt.%lithium-zinc alloy liquid battery has the advantages of stable cycle performance,high discharge capacity and low voltage polarization.In PEO polymer gel electrolyte and PEO gel polymer electrolyte with Li_6.4La₃Zr_1.4Ta_0.6O₁₂ added,10 wt.%lithium-zinc alloy symmetric battery has lower overpotential and voltage polarization value,and the performance is obviously better than pure lithium metal.10 wt.%lithium-zinc alloy solid state battery has more stable coulomb efficiency,faster ion transfer speed,higher discharge capacity and other advantages.