Lattice contraction tailoring in perovskite oxides towards improvement of oxygen electrode catalytic activity

Tailoring the charge density of active metal center is one effective approach to improve the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance by accelerating the rate-determining step. Herein, we propose a novel strategy, that is, lattice contraction tailoring to modulate the charge density of active Co atom in LaCoO 3 by doping Ce ions into the host lattice. The introduction of Ce can boost the bifunctional oxygen electrode activity (0.81 V) with better durability, surpassing the pure LaCoO 3 (1.00 V) catalyst. Due to the improved catalysis performance, the Zn-air battery based on lattice constrain tailoring strategy has demonstrated the 1.2- and 2.0-fold enhancement for current and power densities, respectively. The theoretical calculation reveals that the lattice contraction tailoring in LaCoO 3 can effectively increase the electrical conductivity, decrease the reaction free energy and enhance the rate-determining step rate, which causes the accelerated ORR and OER rates. This study provides a novel insight into designing high-performance oxygen electrocatalyst through engineering the crystal parameters of catalysts.