3D CoMoSe 4 Nanosheet Arrays Converted Directly from Hydrothermally Processed CoMoO 4 Nanosheet Arrays by Plasma-Assisted Selenization Process Toward Excellent Anode Material in Sodium-Ion Battery

In this work, three-dimensional (3D) CoMoSe4 nanosheet arrays on network fibers of a carbon cloth denoted as CoMoSe4@C converted directly from CoMoO4 nanosheet arrays prepared by a hydrothermal process followed by the plasma-assisted selenization at a low temperature of 450 °C as an anode for sodium-ion battery (SIB) were demonstrated for the first time. With the plasma-assisted treatment on the selenization process, oxygen (O) atoms can be replaced by selenium (Se) atoms without the degradation on morphology at a low selenization temperature of 450 °C. Owing to the high specific surface area from the well-defined 3D structure, high electron conductivity, and bi-metal electrochemical activity, the superior performance with a large sodium-ion storage of 475 mA h g−1 under 0.5–3 V potential range at 0.1 A g−1 was accomplished by using this CoMoSe4@C as the electrode. Additionally, the capacity retention was well maintained over 80 % from the second cycle, exhibiting a satisfied capacity of 301 mA h g−1 even after 50 cycles. The work delivered a new approach to prepare a binary transition metallic selenide and definitely enriches the possibilities for promising anode materials in SIBs with high performances.