Mg Doped Perovskite LaNiO₃ Nanofibers as an Efficient Bifunctional Catalyst for Rechargeable Zinc–Air Batteries

Rational design of efficient and durable bifunctional catalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is important for rechargeable zinc–air batteries. Herein, Mg doped perovskite LaNiO3 (LNO) nanofibers (LNMO NFs) were prepared by a facile electrospinning method combined with subsequent calcination. LNMO NFs show a more positive half-wave potential of 0.69 V and a lower overpotential of 0.45 V at a current density of 10 mA cm–2 than those of the pristine LNO NFs. As an air electrode for zinc–air battery, the cell with LaNi0.85Mg0.15O3 NFs catalyst is able to deliver a high specific capacity of 809.9 mAh g–1 at a current density of 5 mA cm–2. It also shows an excellent cycling stability over 110 h at a current density of 10 mA cm–2. DFT calculation results demonstrate that the LNMO surface binds oxygen stronger than LNO, which contributes to enhanced OER activity as observed in our experiments. The results indicate that LNMO NFs are an efficient and durable bifunctional catalyst for zinc–air batteries.