A-site deficient perovskite nanofibers boost oxygen evolution reaction for zinc-air batteries

Among the various perovskites, Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) has been theoretically proved to have the prominent intrinsic oxygen evolution reaction (OER) catalytic activity in the alkaline solutions. Whereas, most of the measured bulk BSCF samples suffer the unsatisfactory OER activities which are much more inferior than that of the state-of-the-art catalyst of IrO2. In this work, we synthesize the A-site deficient BSCF nanofibers with the diameter of 300 nm by electrospinning for the first time. Thanks to the one dimensional (1D) nanofiber structure and A-site deficiency, the optimized BSCF nanofibers (BSCF-80-ES) demonstrate the remarkably enhanced OER activity with a low potential of 1.54 V at 10 mA cm−2 in 1 M KOH and an improved oxygen reduction reaction (ORR) activity. It is noteworthy that the OER potential of BSCF-80-ES keeps almost unchanged during the long-term test, indicating an excellent OER stability. Moreover, BSCF-80-ES with the high bifunctional catalytic activity and superb stability can be used as a promising oxygen catalyst for aqueous and flexible solid-state zinc-air batteries.