Research On The Design Of Lithium Metal Anode Based On Gradient Optimization Strategy

With the application of high energy density in electric vehicles and large-scale energy storage,it is urgent to develop a new generation of energy storage systems with high energy density and long cycle life.Lithium(Li)metal has the highest capacity of3861m Ah g^-1,lowest electrochemical reaction potential(-3.14V)and low density(0.534 g cm^-3)among all electrode materials,which makes it an excellent anode mate-rial for lithium batteries.However,due to the high activity of lithium,lithium dendrites can easily grow on its surface,which seriously limits its practical application.First of all,the three-dimensional frame is an excellent choice for lithium metal storage carrier.In this paper,ZIF-8 was synthesized by simple normal temperature sol-vent method,and carbonized at 800?.It has a porous structure,which can effectively alleviate the volume change of lithium metal in the charging and discharging process.There are many Zn clusters in,which have good lipophilicity and can reduce the nucle-ation overpotential of lithium metal,which is beneficial to the deposition of lithium metal.Subsequently,we applied the synthesized ZIF-8 to modify the diaphragm.Its po-rous structure can effectively fix anions,thus promoting the transport of lithium ions,avoiding the concentration gradient phenomenon near the interface after the depletion of lithium ions,and extending the"Sander time",which is a good carrier for interface stability..The inhomogeneous deposition of lithium metal and the growth of dendrite are the key challenges for the practical application of lithium metal anode.Herein,we demon-strate a promising MOF-derived functional interfacial layer with the gradient litho-philic-lithiophobic and electron conductive-resistive designs in which the top lithiopho-bic and electronic resistive ZIF-8 layer facilitate homogeneous Li⁺flux and formation of stable solid electrolyte interphase.Together with the bottom lithiophilic and high electronic conductivity carbonized ZIF-8,this gradient interfacial layer can effectively suppress dendrite growth,guide homogeneous Li deposition,and achieve stable Li-metal plating/stripping.This strategy is further demonstrated to provide substantially improved rate performance and cycle stabilities in LiCoO₂ full cells.The simple fabri-cation process,multi-functional properties,and wide applicability with varied MOF materials make this gradient interfacial layer is a favored strategy for next-generation lithium-metal batteries.