One-Pot Synthesis of NiSe₂ with Layered Structure for Nickel-Zinc Battery

Transition metal organic framework materials and their selenides are considered to be one of the most promising cathode materials for nickel-zinc (denoted as Ni-Zn) batteries due to their low cost, environmental friendliness, and controllable microstructure. Yet, their low capacity and poor cycling performance severely restricts their further development. Herein, we developed a simple one-pot hydrothermal process to directly synthesize NiSe₂ (denotes as NiSe₂-X based on the molar amount of SeO₂ added) stacked layered sheets. Benefiting from the peculiar architectures, the fabricated NiSe₂-1//Zn battery based on NiSe₂ and the Zn plate exhibits a high specific capacity of 231.6 mAh g^-1 at 1 A g^-1, and excellent rate performance (162.8 mAh g^-1 at 10 A g^-1). In addition, the NiSe₂//Zn battery also presents a satisfactory cycle life at the high current density of 8 A g^-1 (almost no decay compared to the initial specific capacity after 1000 cycles). Additionally, the battery device also exhibits a satisfactory energy density of 343.2 Wh kg^-1 and a peak power density of 11.7 kW kg^-1. This work provides a simple attempt to design a high-performance layered cathode material for aqueous Ni-Zn batteries.