Affiliation:
1. College of Physics, National Demonstration Center for Experimental Applied Physics Education, Qingdao University, Qingdao 266071, P. R. China
Abstract
Transition metal selenides are considered as promising anode materials for sodium-ion batteries (SIBs) due to their high capacity and low cost. However, they suffer from large volume change, serious polyselenide dissolution and sluggish reaction kinetics during charge/discharge process, resulting in poor cycling stability and low rate performance for SIBs, which further restrict their widespread application. Here, we developed carbon-free three-dimensional (3D) hierarchical microflower-shaped CoSe2 with a diameter size of approximately 2[Formula: see text][Formula: see text]m, composed of nanosheets through a one-step solvothermal method. The thin nanosheets are conducive to shortening the Na[Formula: see text] diffusion channels and relieving the volume expansion, and the 3D hierarchical microflower architecture could effectively prevent the agglomeration of nanosheets; accordingly, the resulting CoSe2 microflowers deliver a high specific capacity of 451.94[Formula: see text]mA[Formula: see text]h[Formula: see text]g[Formula: see text] even at 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] after 100 cycles, compared with CoSe2 nanoparticles. This work offers an approach for designing metal selenides with high capacities and rate capability for SIBs.
Funder
National Natural Science Foundation of China
Shandong Natural Science Foundation
Publisher
World Scientific Pub Co Pte Ltd
Subject
Condensed Matter Physics,General Materials Science