Large ligand metal-organic framework derived CoSe2 to improve sodium storage performance

Cobalt selenide has been regarded as a promising anode for sodium-ion battery owing to its high capacity. However, the issues of stacked problem and volume expansion during cycling significantly affects its performance. Herein, we used large-size ligands to successfully prepared a new cobalt metal-organic frameworks (MOFs), and used as a precursor to prepare CoSe2/MOFc by high-temperature selenization. Morphology characterizations revealed that due to the blocking effect of large-sized ligands, CoSe2 nanoparticles were evenly distributed on the carbon material. As an anode, CoSe2 /MOFc shows a good cyclic stability and high capacity (291 mAhg(-1) after 1000 cycles at 1 Ag-1) due to the well dispersion of CoSe2 nanoparticles and the effective coating of carbon matrix. These results indicated that utilizing MOFs precursor with large ligands facilitates the distribution of nanoparticles on conductive carbon, allowing for the synthesis of sodium-ion battery electrodes with superior properties.