摘要
Three-dimentional(3D)transition metal selenides with sufficient channels could produce significant superiority 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 Cu_(2-x)Se film was epitaxial grown on(220)facets-exposed Cu by direct selenization of a nanoporous Cu skeleton,which is obtained by dealloying rolled Cu Mn@Cu alloy foil.Density functional theory calculation result shows strong adsorption energy for Se atoms on Cu(220)planes during selenization reaction,rendering 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 Cu_(2-x)Se@Cu-0.15 composite electrode exhibits remarkable sodium-ion storage properties with high reversible capacity of 950.6μAh/cm^(2)at 50μA/cm^(2),suprior rate capability of 457.6μAh/cm^(2)at 500μA/cm^(2),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
financially supported by the National Natural Science Foundation of China(Nos.52271011,52102291,52101251)。
