A fast-kinetics ternary composite cathode design for high-rate aqueous zinc-ion batteries

Aqueous zinc-ion battery (AZIB) attracts a great attention and becomes a hotspot due to its low cost and high safety in recent years. However, the sluggish transport kinetics of cathode materials is a significant drawback limiting their application. Herein, this work reports a novel VSe 2 /V 2 O 5 · n H 2 O/reduced graphene oxide ternary composite (VSe 2 /V 2 O 5 · n H 2 O/rGO) constructed with an anti-aggregation and porous 3D framework. The as-prepared ternary composite acting as cathode for AZIBs could provide a high capacity of 327.4 mA h g −1 at the current density of 0.2 A g −1 . More importantly, it also possesses excellent rate capability and cyclic stability, which deliver a specific capacity of 254 mA h g −1 at a high current density of 5 A g −1 . In addition, the structural evolution and transport kinetics of VSe 2 /V 2 O 5 · n H 2 O/rGO upon cycling are investigated. Benefiting from the high reversibility of phase evolution and the reduced graphene oxide (rGO) composition, the prepared VSe 2 /V 2 O 5 · n H 2 O/rGO can maintain a robust structure during cycling, improve the transport kinetics and thus displaying an outstanding electrochemical performance. This study offers a new route for designing cathode materials and promoting the development of high-performance AZIBs.