FeSe hollow spheroids as electrocatalysts for high-rate Li–O2 battery cathodes

Abstract In this study, FeSe hollow spheroids were prepared for application as cathode electrocatalysts in Li–O2 batteries. The hollow spheroids were synthesized through hydrothermal and thermal selenization processing based on a silk–fibroin template. At the high current rate of 1000 mA g−1, the FeSe spheroids exhibited higher reversibility (100 cycles) and a similar voltage gap to that at 200 mA g−1. Therefore, FeSe hollow spheroids exhibit high oxygen reduction/evolution catalytic efficiency for high–rate Li–O2 batteries. This result was demonstrated via comparison of the oxygen reduction/evolution kinetics of FeSe and Fe2O3 hollow spheroids using electrochemical impedance spectroscopy.