三维多孔铜及表面修饰铋协同构筑无枝晶锂金属电极OA北大核心CSTPCD

In this paper,three-dimesional(3D)Cu@Bi was constructed by electrodepositing a bismuth modification layer on the surface of 3D porous copper with micrometer-sized pores prepared by an electroless plating,and served as the current collector to improve the electrochemical performance of Li metal electrode.The 3D porous structure with a pore diameter of about 5 μm has a high surface area,which reduces the local current density and results in uniform current density distribution,and its large free space can alleviate the volume change,release the stress and inhibit the growth of lithium dendrites.In addition,under the assistance of high lithophilicity of Bi modified layer,the 3D Cu@Bi decreases the nucleation overpotential of Li,and enhances the reversibility of lithium plating/stripping.Under the synergistic effects of 3D porous structure and Bi modified layer,the electrode surface remains flat and smooth even when the lithium metal deposition capacity is more than 4 mA·h/cm2.The half cells assembled by it can be stably cycled for more than 200 cycles and the Coulomb efficiency(CE)can be maintained above 98.5%.The symmetrical cell Li||3D Cu@Bi@Li stably circles for above 1500 h at high current density of 0.5 mA/cm2 with a capacity of 1 mA·h/cm2,and the electrode surface is still smooth and free of dendrites after 100 cycles.The full cell LFP||3D Cu@Bi@Li with LiFePO4(LFP)as the cathode shows a high capacity of 132 mA·h/g and a capacity retention rate of ca.87.2%after 200 cycles at a rate of 1C.