Silver-Intermediated Perovskite La_0.9FeO_3−δ toward High-Performance Cathode Catalysts for Nonaqueous Lithium–Oxygen Batteries

Abstract

Development of efficient cathode catalysts is crucial for achieving high-performance rechargeable lithium–oxygen batteries. Herein, a simple one-step electrospun method was applied to obtain a silver-modified perovskite La0.9FeO3−δ (Ag@LFO) as an efficient cathode catalyst. The synthesized catalyst has two characteristics: first, the doping of Ag led to a tailored electronic structure including the generation of Fe4+; second, the in situ grown Ag exhibits a stronger interaction with perovskite. These two advantages result in high oxygen adsorbability and increased percentage of highly active oxygen species. Therefore, film-like Li2O2 was observed during discharge on the Ag@LFO cathode, which is beneficial for decomposition during recharge, whereas Li2O2 generated on the LFO cathode was largely toroidal. Density functional theory calculations were used to discuss the Li2O2 growth mechanism. As a result, compared to La0.9FeO3−δ and post-loading silver-decorated La0.9FeO3−δ (Ag/LFO), Ag@LFO exhibits lower overpotential, improved rate-capability, higher discharge specific capacity, and especially promoted cycling performance that is triple that of LFO.