Hierarchically structured Mo1–2C/Co-encased carbon nanotubes with multi-component synergy as bifunctional oxygen electrocatalyst for rechargeable Zn-air battery

Abstract

The development of efficient and durable non-precious metal-based bifunctional oxygen electrocatalysts is pivotal in realizing cost-effective and high-performance rechargeable Zinc-Air Batteries (ZABs). In this study, a straightforward hydrothermal-melamine-assisted carbonization method is employed to synthesize a hierarchical core-shell structure comprising Mo2C/MoC intertwined with cobalt-incorporated N-doped carbon nanotubes (Mo2C/MoC/Co@CNTs). The synergy between Mo2C/MoC and Co@CNTs is harnessed to achieve remarkable bifunctional OER/ORR activities, as evidenced by a small potential gap (ΔE = Ej = 10 – E1/2) of 0.74 V between OER and ORR. When integrated into a liquid ZAB, the assembled battery delivers a remarkable peak power density of 134 mW cm−2 and exhibits a robust cycling performance, sustaining continuous operation for 275 h at a current density of 10 mA cm−2. This work not only presents a strategic approach to developing electrocatalysts with specific components, but also underscores the significance of multi-component synergy in electrocatalytic applications.