A telluride-doped porous carbon as highly efficient bifunctional catalyst for rechargeable Zn-air batteries

Abstract

The development of high-efficiency, low-cost, and stable bifunctional catalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of great significance to the large-scale application of zinc–air batteries. Here we synthesized a telluride (Te)-doped porous carbon catalyst (ZnCo-Te@NC) through pyrolyzing ZnCo-MOF-coated Te nanotubes. The as-prepared ZnCo-Te@NC exhibited excellent bifunctional electrocatalytic performance with an impressive half-wave potential (E1/2) of 0.873 V for ORR and a low overpotential of 400 mV at 10 mA cm−2 for OER, outperforming most non-noble metal-based catalysts previously reported. When using ZnCo-Te@NC as the air cathode catalyst in a self-assembled battery, it demonstrated smaller charge-discharge voltage gap (0.932 V at 50 mA cm−2) and higher peak power density (259.7 mW cm−2) with robust long-term (100 h) cycle stability, surpassing the benchmark precious metal catalyst-based batteries. This is the first report that telluride has been doped into a highly graphitized porous carbon for use in zinc-air batteries. This work provides an effective strategy to develop high graphitized carbon materials by telluride modification to enhance the performance of bifunctional electrocatalysts for Zn–air batteries.