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

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.