Abstract
Vanadium nitride (VN) with high theoretical specific capacity and electrical conductivity is promising for application in Zn-air batteries. However, the agglomeration phenomenon during the synthesis of VN nanoparticles resulted in poor catalytic activity. Therefore, a highly efficient and durable ORR catalyst that vanadium nitride nanoparticles supported on nitrogen-doped carbon (VN/NC/C) was prepared by a self-assembly. Benefiting from the synergistic effect of VN and NC as well as its large specific surface area, porous structure, abundant pyridine N and graphitic N, the VN/NC/C nanocomposites exhibits excellent catalytic activity with Eonset of 0.87 V, a limiting current density of 4.05 mA·cm−2, and good stability. The experimental results and DFT calculations show that benefiting from the synergistic effect of NC and VN, the free energies of the reaction intermediates are optimized to significantly accelerate the O2 adsorption and reduce the potential of the rate-determining step. The Zn-air battery assembled with VN/NC/C nanocomposites exhibits an open circuit potential of 1.30 V, high power density of 141.82 mW∙cm−2 and an energy density of 856.27 Wh·kgZn-1. This work demonstrates the importance of the synergistic effect of NC and VN in the development of high-performance Zn-air batteries.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
