High surface area for La1-xSrxFeO3 (x=0, 0.4, 0.6) as bifunctional catalyst for rechargeable Li-O2 batteries

Abstract

Three-dimensionally mesoporous La_1-xSr_xFeO₃ (x = 0, 0.4, 0.6) precursors have been synthesized through a facile solvothermal process. After high-temperature sintering, La_1-xSr_xFeO₃ still exhibits uniform morphology and good dispersibility, which provides a porous structure and favorable surface area. Particularly, La_0.4Sr_0.6FeO₃ shows the biggest surface area of 58 m² g^-1. Doping also induces the generation of oxygen vacancies and Fe⁴⁺, which is beneficial for the conductivity and catalytic activity of the materials. Complete with favorable structure and electrochemical activity, La_0.4Sr_0.6FeO₃ exhibits bifunctional catalytic activity in alkaline solution. Applied as a cathode catalyst in Li-O₂ batteries, it shows a larger discharge capacity of 23 905 mA h g^-1 and a better cycling stability of 100 cycles.