A facile strategy for the synthesis of graphene/V2O5 nanospheres and graphene/VN nanospheres derived from a single graphene oxide-wrapped VOx nanosphere precursor for hybrid supercapacitors

作者：Sun, Wei; Ji, Xiujie; Gao, Guohua^*; Wu, Guangming^*

来源：RSC Advances, 2018, 8(49): 27924-27934.

DOI：10.1039/c8ra05298k

• HIGH-ENERGY DENSITY
• HIGH-POWER DENSITY
• ACTIVATED CARBON
• COMPOSITE
• AEROGELS
• STORAGE
• ANODE
• ELECTRODES
• CAPACITANCE
• SURFACE

It remains a challenge to develop a facile approach to prepare positive and negative electrode materials with good electrochemical performance for application in hybrid supercapacitors. In this study, based on a facile strategy, a single graphene oxide-wrapped VOx nanosphere precursor is transformed into both electrodes through different thermal treatments (i.e., graphene/VN nanospheres negative electrode materials and graphene/V2O5 nanospheres positive electrode materials) for hybrid supercapacitors. The conformally wrapped graphene has a significant influence on the electrochemical performance of VN and V2O5, deriving from the simultaneous improvements in electronic conductivity, structural stability, and electrolyte transport. Benefitting from these merits, the as-prepared graphene/VN nanospheres and graphene/V2O5 nanospheres exhibit excellent electrochemical performance for HSCs with high specific capacitance (83 F g(-1)) and good long cycle life (90% specific capacitance retained after 7000 cycles). Furthermore, graphene/VN nanospheres//graphene/V2O5 nanosphere HSCs can deliver a high energy density of 35.2 W h kg(-1) at 0.4 kW kg(-1) and maintain about 70% high energy density even at a high power density of 8 kW kg(-1). Such impressive results of the hybrid supercapacitors show great potential in vanadium-based electrode materials for promising applications in high performance energy storage systems.

• 出版日期2018
• 单位同济大学