Abstract
Carbon nanofibers(CNFs)with high specific surface area show great potential for sodium storage as a hard carbon material.Herein,CNFs anchored with Ni nanoparticles(CNFs/Ni)were prepared through chemical vapor deposition and impregnation reduction methods,in situ growing on the three-dimensional porous copper current collector(3DP-Cu).The coupling effect of high-spin state Ni nanopar-ticles leads to the increase of defect density and the expansion of lattice spacing of CNFs.Meanwhile,the 3DP-Cu ensures a high loading capacity of CNFs and short ion/electron transport channels.As an integral binder-free anode,the 3DP-Cu/CNFs/Ni exhibits excellent electrochemical performance,which demon-strates a high specific capacity with 298.5 mAh g-1 at 1000 mA g-1 after 1500 cycles,and a high power density with 200 mAh g-1 over 1000 cycles at 5000 mA g-1.Density functional theory calculation re-sults show that the high-spin state Ni regulates the electronic structure of CNFs,which significantly re-duces the adsorption energy for Na+(-2.7 Ev)and thus enables high-rate capability.The regulation of the electronic structure of carbon materials by high-spin state metal provides a new strategy for developing high-power carbonaceous anode materials for sodium-ion batteries.
基金项目
National Natural Science Foundation of China(52271011)
National Natural Science Foundation of China(52102291)
NETL
NSTL
万方数据