A single-step synthesis and direct growth of microspheres containing the nanoflakes-like structure of Zn 0.76 Co 0.24 S as a high-performance electrode for supercapacitors

Selecting suitable active materials with unique design microstructures can deliver a new generation of supercapacitors with high energy-storage performance. In this work, Zn0.76Co0.24S microspheres containing nanoflakes on its surface were successfully synthesized using a simple one-step hydrothermal method, achieving an excellent electrochemical energy storage behavior owing to its good conductivity, and unique structure that allowed effective transportation paths for ions/electrons. The as-prepared Zn0.76Co0.24S was used as an electrode material for supercapacitors, and it displayed an excellent capacitance of 2393 F g(-1) (796 C g(-1)) at 1 A g(-1). For a real application, a hybrid device was assembled using Zn0.76Co0.24S as a positive electrode and activated carbon as a negative electrode. This led to delivering high specific energy of 58.8 Wh kg(-1) at a specific power of 815 W kg(-1), showing excellent cycling stability of 90% capacity retention of the initial capacity after 5000 cycles.