Exploration of potential-limited protocols to prevent inefficiencies in Li–O 2 batteries during charge †

Abstract

Metal–air batteries are promising energy storage systems with high specific energy density and low dependence on critical materials. However, their development is hindered by slow kinetics, low roundtrip efficiency, deficient capacity recovery, and limited lifetime. This work explores the effect of cycling protocols on the lifetime of Li–O2 cells, and the interplay between electrolyte composition and the upper cut-off voltage during charge. Our results suggest that constant-current-constant-voltage (CCCV) protocols accommodate the slower kinetics at the end of charge in Li–O2 cells better than the constant-current (CC) protocols majorly used in the field. These results suggest that CCCV protocols should be standardised to assess performance improvements in Li–O2 cells.