Peach Gum‐Derived S,N Co‐Doped Nanoporous Carbon Coupled with Layered Double (Ni, Fe) Hydroxide for Efficient Bifunctional Oxygen Electrocatalysis in Zn‐Air Batteries

Abstract

AbstractLow‐cost and high activity bifunctional oxygen electrocatalysts are at the heart of developing advanced rechargeable Zn‐air batteries (ZABs), but the challenges are great. Herein, a highly efficient hybrid catalyst, consisting of S, N co‐doped nanoporous carbon (SNC) coupled with in‐situ growth layered double (Ni, Fe) hydroxide (LDH), was derived from the biomass peach gum by a series of treatments, including hydrothermal carbonization, alkali activation, S/N co‐doping and metal‐coprecipitation process. Benefiting from the coexistence of active sites for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), the hybrid (NiFe‐LDH/SNC) reveals excellent bifunctional electrocatalytic activity with a small ΔE of 794 mV. Furthermore, as the cathode bifunctional catalyst for ZAB, the battery with NiFe‐LDH/SNC displays a large open‐circuit voltage of 1.36 V, a high power density/specific capacity of 100 mW cm−2/816 mAh gZn−1, and superior cycling durability up to 500 h at a charge/recharge current density of 2 mA cm−2, indicating its great application potential in the rechargeable metal‐air batteries.