Effect of LiBOB content on electrochemical performance of Li–O2 batteries

Lithium-oxygen batteries show great energy storage potential due to their high energy density . However, it is difficult for conventional liquid electrolytes to form a stable solid electrolyte interface (SEI) on cathode surface to ensure long-term stable cycling of lithium-oxygen batteries . Herein, LiBOB is added to the LiTFSI-based electrolyte to solve the above-mentioned problems. By introducing LiBOB into LiTFSI single-salt electrolyte system, the electron delocalization of the BOB − anion induces the dissociation equilibrium of the lithium salt to occur positively and the formed electrolyte exhibits good ionic conductivity . Different amounts of LiBOB show different characteristics in electrochemical performance. Trace amounts of LiBOB as an additive increase the solvation of Li + and improve the discharge capacity of the cell. Furthermore, the synergistic effect of the LiTFSI-LiBOB dual-salt electrolyte forms a protective SEI when LiBOB has a larger proportion of lithium salts in the electrolyte, resulting in comparable cycling performance. This work demonstrates a promising approach to design electrolytes for long-term stable cycling of lithium-oxygen batteries.