▎ 摘　　要

In order to cope with the problem of insufficient lithium metal reserves, sodium ion batteries (SIBs) are proposed and extensively studied for the next-generation batteries. In our work, hierarchical NiCo2Se4 nanoneedles/nanosheets are deposited on the skeleton of N-doped three dimensional porous graphene (NPG) by a convenient solvothermal method and subsequent gas-phase selenization process. Compared with NiCo2Se4 powder, the optimized NiCo2Se4/N-doped porous graphene composite (denoted as NCS@NPG) as self-supporting anode exhibits the excellent electrode activity for SIBs, with a specific capacity of 500 mAh/g and 257 mAh/g at a current density of 0.2 A/g and 6.4 A/g, respectively. The high specific capacity as well as rate capacity can be attributed to the three-dimensional graphene skeleton with high electrical conductivity and pore structure, which provides convenient ion and electron transmission channels. (c) 2020 Elsevier Inc. All rights reserved.