Controllable synthesis of vanadium-doped nickel-chalcogenide/graphene cathodes and MnV2O6.2H2O/graphene anode for high-energy asymmetric supercapacitors

Exploring novel electrode materials with rational morphology and structure is crucial for the fabrication of high-performance supercapacitors. In this work, novel vanadium-doped nickel-chalcogenide/reduced graphene oxide cathodes (NiV-S/rGO and NiV-Se/rGO) and MnV2O6.2H(2)O/rGO anode are controllably prepared through a facile solvothermal method. Benefiting from the two-dimensional structure and desirable surface electronic environment, the graphene-supported NiV-X/rGO (X = S and Se) cathodes exhibit outstanding capacitive performance (1734.2 and 1577.2C.g(-1) at 2 A.g(-1)), remarkable cycling stability and exceptional rate performance. Meanwhile, with the encapsulation of graphene protect layers, the MnV2O6.2H(2)O/rGO anode also shows a significantly enhanced specific capacity and superb cycling stability (95.8 % retention after 10,000 cycles). When assembled into asymmetric supercapacitors, the NiV-S/rGO//MnV2O6.2H(2)O/rGO and NiV-Se/rGO//MnV2O6.2H(2)O/rGO devices not only exhibit ultra-high energy densities (82.4 and 60.0 Wh.kg(-1) at a power density of 800.0 W.kg(-1)), but also display superior cycling stabilities (91.5 % and 93.7 % retention after 10,000 cycles). These excellent properties demonstrate their potential application prospect in supercapacitor with high energy densities.

Automated summary

Novel vanadium-doped nickel-chalcogenide/reduced graphene oxide cathodes and MnV2O6.2H(2)O/rGO anode were prepared through a solvothermal method. These electrode materials exhibited outstanding capacitive performance, remarkable cycling stability, and exceptional rate performance, showing potential application prospects in high energy density supercapacitors.