One-step construction of mesh-like CoSe2 microflowers for magnesium–lithium hybrid batteries with enhanced rate performance

Abstract

Magnesium–lithium hybrid-ion batteries are a potential energy storage device possessing fast ion migration kinetics and high safety. A CoSe₂ was prepared using a one-step solvothermal preparation of mesh-like microflowers, which can provide shorter paths for ion diffusion and buffer space for volume changes during electrochemical reactions. The discharge specific capacity is maintained at 361.9 mAh g⁻¹ after 500 cycles at 1 A g⁻¹. In addition, the CoSe₂ has a high-rate performance, with 452.0 mAh g⁻¹ discharge capacity at 0.2 A g⁻¹, and a 332.0 mAh g⁻¹ discharge capacity at 2 A g⁻¹. This work confirms that CoSe₂ is an appropriate cathode material for high-performance magnesium–lithium hybrid-ion batteries.