Design of all-solid-state hybrid supercapacitor based on mesoporous CoSnO3@RGO nanorods and B-doped RGO nanosheets grown on Ni foam for energy storage devices of high energy density

Designing advanced hybrid supercapacitors (SCs) with high energy density and long-term cycling stability remains a vital hurdle. We introduce CoSnO3, a battery anode material, to the SCs as a positive electrode through a simple synthesis of unique mesopomus CoSnO3 nanorods@reduced graphene oxide (RGO) composite, which delivers a specific capacity of 855.9 C g(-1) (1902 F g(-1)). A porous boron-doped RGO nanosheets (B-RGO) electrode fabricated provides a remarkable specific capacity of 305.2 C g(-1) (254.4 F g(-1)) in 2 M KOH. Hybrid supercapacitor constructed with CoSnO3@RGO composite (positive electrode) and B-RGO nanosheets (negative electrode) has a voltage window of 1.5 V with a specific capacity of 286.1 C g(-1) (190.7 F g(-1)) at 2 A g(-1). The assembled device provides a remarkable energy density of 76.1 Wh kg(-1) at the power density of 1915.8 W kg(-1). It is also endowed with suitable cycling stability, retaining more than 93% of its capacity after 10,000 cycles.