Nickel–cobalt–manganese ternary electrodes with CEI film evolution via ORR-regulated pH modulation in zinc-ion batteries

Abstract

In this study, a Ni–Co-based electrode capable of catalyzing the oxygen reduction reaction (ORR) was prepared via electrodeposition and integrated with a Mn-rich electrolyte to develop a novel ternary zinc-ion battery. The battery operates within a voltage range of 0–1.85 V, with its cathode facilitating ORR at 0.2 V, thereby regulating the operational environment and directing Mn²⁺ deposition from the Mn-rich electrolyte. Results indicate that only electrodes with a specific Ni/Co ratio exhibit ORR catalytic activity. Furthermore, the cathode–electrolyte interface (CEI) film undergoes spontaneous evolution post-ORR. Continuous replacement of the CEI film-from an initial inert phase to an active phase-enhances capacity, achieving a peak capacity of 1504.14 mA h g⁻¹ at 10 A g⁻¹. This work synergizes the advantages of zinc–manganese, zinc–nickel, and zinc–air batteries, offering new insights into advanced zinc-ion battery design.