摘要
The N-doping strategy is considered an effective method to regulate the electronic structure of carbon materials and improve their electrochemical performance.However,how to reasonably regulate the types of N-doping species remains a major challenge.Herein,we reported a self-supporting carbon nanofiber electrode codoped with N and Se(N/Se-CNF)for flexible zinc ion capacitor(ZIC).It was found that Se atoms can induce the reduction of Pyrrole-N,which is favorable for Zn ions transfer.Furthermore,ex-situ characterizations and theoretical density functional theory(DFT)calculations have shown that additional Se atoms can provide abundant reaction sites and reduce the adsorption energy of Zn ions.Accordingly,the N/Se-CNF electrode demonstrates impressive rate performance.The N/Se-CNF electrode shows impressive rate performance,retaining 60%capacitance at 20 A·g^(-1),with an energy density of 95.3 Wh·kg^(-1) and power density of 160.1 W·kg^(-1),and a commendable stability cycle,the capacitance retention is 88.1%after 18,000 cycles at a discharge rate of 5 A·g^(-1).Moreover,a flexible ZIC with N/Se-CNF electrode exhibits a high energy density of 68.8 Wh·kg^(-1) at 160 W·kg^(-1).This strategy innovatively regulates N-doping species and offers potential flexible electrodes for advanced energy storage devices.
基金
National Natural Science Foundation of China(No.52376060).
