Anti-aggregation growth and hierarchical porous carbon encapsulation enables the C@VO2 cathode with superior storage capability for aqueous zinc-ion batteries

Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries (AZIBs). In this work, we report the construction of C@VO2 composite via anti-aggregation growth and hierarchical porous carbon encapsulation. Both of the morphology of composite and pore structure of carbon layer can be regulated by tuning the adding amount of glucose. When acting as cathode applied for AZIBs, the C@VO2-3:3 composite can deliver a high capacity of 281 mAh g-1 at 0.2 A g-1. Moreover, such cathode also exhibits a remarkably rate capability and cyclic stability, which can release a specific capacity of 195 mAh g-1 at 5 A g-1 with the capacity retention of 95.4% after 1000 cycles. Besides that, the evolution including the crystal structure, valence state and transport kinetics upon cycling were also deeply investigated. In conclusion, benefited from the synergistic effect of anti-aggregation morphology and hierarchical porous carbon encapsulation, the building of such C@VO2 composite can be highly expected to enhance the ion accessible site, boost the transport kinetics and thus performing a superior storage performance. Such design concept can be applied for other kinds of electrode materials and accelerating the development of highperformance AZIBs. (c) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

In this work, a C@VO2 composite was constructed via anti-aggregation growth and hierarchical porous carbon encapsulation to improve the electrochemical performance of aqueous zinc-ion batteries (AZIBs). The morphology and pore structure of the composite can be regulated by tuning the adding amount of glucose. The C@VO2-3:3 composite delivered a high capacity of 281 mAh g-1 at 0.2 A g-1 as a cathode for AZIBs, and exhibited remarkable rate capability and cyclic stability. The evolution of crystal structure, valence state, and transport kinetics upon cycling was also investigated. The synergistic effect of anti-aggregation morphology and hierarchical porous carbon encapsulation in the C@VO2 composite enhances the ion accessible site and transport kinetics, resulting in superior storage performance. This design concept can be applied to other types of electrode materials, accelerating the development of high-performance AZIBs.