Pt nanoparticle-embedded NiFe-LDH nanoflowers as a high-performance cathode for rechargeable aqueous zinc–air batteries

Abstract

Rechargeable aqueous Zn–air batteries (ZABs) are promising due to their high energy density (1370 Wh kg⁻¹), safety, and environmental friendliness, but their development is hindered by slow oxygen redox kinetics. Herein, we have synthesized Pt nanoparticle-embedded NiFe layered double hydroxide (Pt/NiFe-LDH) nanoflowers via an in situ reduction method. As a cathode, Pt/NiFe-LDH can exhibit remarkable bifunctional activity with an impressive ΔE value of 0.631 V, which achieves a half-wave potential of 0.861 V for the oxygen reduction reaction and a low overpotential of 262 mV at 10 mA cm⁻² for the oxygen evolution reaction, surpassing commercial Pt/C and RuO₂ benchmarks. When deployed in ZABs, the Pt/NiFe-LDH cathode delivers remarkable cycling stability over 1300 h.