Fluorine induced surface reconstruction of perovskite ferrite oxide as cathode catalyst for prolong-life Li-O2 battery

Lithium-oxygen batteries are widely studied because of the highest theoretical specific energy density among candidates for next-generation energy storage devices. However, the insulated bulk Li2O2 generated during discharge restricts their further development. Here, we demonstrate a surface reconstruction strategy on perovskite La0.8Fe0.9Co0.1O3-delta(LFCO) to construct a LaF3/LFCO composite, which induces a modified surface and also manipulates the electronic structure. The optimized surface and electronic structure adjust the discharge reaction pathway and form thin petal-like F doped Li2O2, which have better conductivity compared to traditional discharge product and benefit for Li-O2 battery performance. This LaF3/LFCO leads to much better cycle stability (157 vs 57 cycles) in comparison to the pristine LFCO. This work suggests surface reconstruction provides a new approach in the design of cathode catalyst for long-life lithium-oxygen battery.