One-step synthesis of CoSe modified ZnSe hybrid as a battery-type cathode material for supercapacitors with improved electrochemical performance

Transition metal selenides (TMSs), as a novel type of battery-type electrode material for high-performance supercapacitors, have gradually attracted growing attention in recent years. Herein, the new three-dimensional interconnected ultrathin CoSe nanosheets decorated ZnSe nanoparticles-assembled microspheres hybrid was prepared through a simple one-pot hydrothermal method and employed as battery-type supercapacitor cathode materials for the first time. Benefiting from the unique intertwined structure with a high surface area, mesopore/macropore-rich hierarchical structure as well as superior electrical conductivity, compared with the pure monometallic ZnSe electrode, the as-prepared CoSe/ZnSe hybrid electrode presents significantly boosted electrochemical performances with a high specific capacity of 92.0 mAh g(- 1) at 1 A g(- 1), admirable rate property with 46.5% of capacity retention at 50 A g(- 1) and superior cycle performance with 88.2% of capacity retention after 5000 cycles at 10 A g(- 1). These intriguing data imply that the resultant CoSe/ZnSe hybrid can be seen as a promising cathode material for battery-type supercapacitors.