Superiority of Cubic Perovskites Oxides with Strong B-O Hybridization for Oxygen-Anion Intercalation Pseudocapacitance

摘要

Perovskite materials can store charge through rapid oxygen anions intercalation.Although numerous perovskite materials owing to rich selectionsof A and B-site elements are reported as electrodes of supercapatteries, theeffect of the crystal structure of perovskite materials on their electrochemicalperformance has never been studied so far. Herein, using SrCo_(0.9)Mo_(0.1)O_(3?δ),SrFeO_(3?δ), Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3?δ), and LaMnO_(3?δ) as research targets, it isproved that their corresponding cubic structure materials display the bestelectrochemical performance. And then, the origin of such superiority ofcubic structure for SrCo_(0.9)Mo_(0.1)O_(3?δ) is explored through experimental investigationsand theoretical calculations. The results show that the increase inthe content of oxygen vacancies and the enhancement of B-O hybridizationof cubic structure can optimize the electronic structure of the perovskitematerials, thereby improving its conductivity and accelerating the reactionkinetics. The filtering strategy based on crystal structure proposed by thisreport will provide a new perspective to faster and more efficient choice ofperovskite materials for supercapatteries.