Research On Synthesis And Performanceof Modified Metal Foam Used In Lithium Metal Anode

Because metal lithium has the lowest electrode potential(-3.045 V,compared to standard hydrogen electrodes)and ultra-high theoretical capacity(3860 m Ah·g^-1 or 2061m Ah·cm^-2),pure lithium metal is used as the anode material.The lithium metal battery is currently considered to be the most promising new generation of energy storage device.However,the lithium metal is chemically lively and the"host-free"behavior of lithium during deposition will cause the unlimited increase in the volume of the lithium negative electrode,the surface SEI film ruptures,and the formation of"dead lithium",which affects the efficiency of the battery and may also cause safety accidents such as short circuit.Solutions to this include the use of solid electrolytes,artificial SEI membranes,and the use of 3D current collectors.Here,this experiment uses foamed metal as the 3D current collector of the anode electrode of the lithium metal battery,and improves the performance and service life of the lithium metal battery by modifying it.The copper nanosheet modified foamed copper current collector with high electrochemical stability is prepared by simple hydrothermal and reduction methods,which increases the specific surface area with the original foamed copper,and provides a large number of nucleation sites for the deposition of lithium at the negative electrode.Guide the uniform deposition of lithium and form a flat and smooth surface to form a stable SEI film.The symmetrical battery assembled with these advantages shows a cycle life of more than 600 h at a current density of 1 m A·cm^-2,and the full battery assembled with Li Fe PO₄maintains a reversible capacity of 89.92%after a stable cycle of 300 cycles.The zinc oxide flower rod-like nanostructure is grown on the surface of Ni foam by hydrothermal method to enhance the lithium affinity of the material,and the molten metal lithium is poured into the modified Ni foam to obtain a ZnO-NF/Li composite negative electrode material.While providing higher energy density,it also retains the basic skeleton structure of Ni foam.The ZnO-NF/Li composite anode material provides a large number of nucleation sites for lithium deposition during the cycle,which can effectively guide the uniform deposition of lithium,ensure the integrity of the SEI film,and significantly alleviate the problem of negative electrode volume expansion.The assembled symmetrical battery can be cycled stably for 500 hours,and the ZnO-NF/Li|LFP full battery also has matching excellent electrochemical stability and rate performance.