Abstract
Three-dimentional(3D)transition metal selenides with sufficient channels could produce significant su-periority on enhancing reaction kinetics for sodium-ion batteries.However,the thorough exploration of 3D architecture with a facile strategy is still challenging.Here we report that a polycrystalline Cu2-xSe film was epitaxial grown on(220)facets-exposed Cu by direct selenization of a nanoporous Cu skeleton,which is obtained by dealloying rolled CuMn@Cu alloy foil.Density functional theory calculation result shows strong adsorption energy for Se atoms on Cu(220)planes during selenization reaction,render-ing a low energy consumption.By virtue of this core-shell 3D nanoporous architecture to offer abundant active sites and endow fast electron/ion transportation,the nanoporous Cu2-xSe@Cu-0.15 composite elec-trode exhibits remarkable sodium-ion storage properties with high reversible capacity of 950.6 μAh/cm2 at 50 μA/cm2,suprior rate capability of 457.6 μAh/cm2 at 500 μA/cm2,as well as an ultra-long stability at a high current density.Mechanism investigation reveals that the electrochemical reaction is a typical conversion-type reaction with different intermediates.This novel electrode synthetic strategy provides useful instructions to design the high-performance anode material for sodium-ion batteries.
基金项目
National Natural Science Foundation of China(52271011)
National Natural Science Foundation of China(52102291)
National Natural Science Foundation of China(52101251)
万方数据