Enhanced and stabilized charge transport boosting by Fe-doping effect of V2O5 nanorod for rechargeable Zn-ion battery

Abstract

As a result of prices of fossil fuels and the increased energy demand, reasonable utilization of renewable energy sources has become a global topic, rechargeable aqueous zinc-ion batteries (ZIBs) are considered as the large-scale energy storage because there is an abundant zinc source, and ZIBs provide reliable safety, eco-friendliness, and high specific capacity. Nevertheless, the limited electroactive sites and low electrical conductivity of vanadium oxide (V2O5)-based cathode for ZIBs inevitably destabilizes the energy storing reactions, impeding the diffusion of zinc ion and electron movement. Here, to lower the insertion energetics and diffusion barriers of zinc ion, we reported iron (Fe)-doped V2O5 with the nanorod architecture by utilization of electrospun polyacrylonitrile fiber templates; these exhibited a high energy density of 540 W h kg−1 at a power density of 600 W kg−1, and a good capacity retention of 85% after up to 160 cycles. The Fe-doping effects in V2O5 matrix with the nanorod architecture provides abundant contact with electrolyte, an increased electrical conductivity, and shortened ionic diffusion distance during electrochemical processes, facilitating overall energy-storing performance. This work provides a necessary strategy for designing next-generation high-performance energy storage devices.