Plasma‐Assisted Nitridation Modulates the Electronic Structure of the NiSe ₂ /Ni@Ni ₃ N Ternary Heterojunction Enhancing Its Dual‐Function Catalytic Performance and Inhibiting Zn Dendrite Growth in Rechargeable Zinc‐Air Batteries

Abstract In this work, a novel synthetic strategy to construct a structurally advanced bifunctional electrocatalyst via Ar/NH ₃ radio‐frequency plasma‐assisted nitridation and subsequent high‐temperature selenization is proposed. The resulting self‐supporting electrode, denoted as p‐NiSe ₂ /Ni@Ni ₃ N/NCNT@CC, consists of selenium‐vacancy‐rich NiSe ₂ /Ni@Ni ₃ N nanoparticles (NPs) uniformly anchored on nitrogen‐doped carbon nanotubes (NCNTs) in situ grown on carbon‐cloth (CC). The formation of this ternary heterostructure is governed by interactions between plasma‐generated reactive species (NH*, NH ₂ *, Ar*) and Ni NPs. It demonstrates outstanding bifunctional performance and stability in 0.1 m KOH, featuring a half‐wave potential for oxygen‐reduction reaction (ORR) of 0.80 V, an overpotential of 311 mV for oxygen‐evolution reaction (OER) at 30 mA cm⁻ ² , and a minimal ΔE of 0.74 V, surpassing commercial Pt/C+RuO ₂ . Liquid zinc–air batteries (L‐ZABs) using this catalyst as the air cathode deliver a high peak power‐density of 137.94 mW cm⁻ ² and stable cycling over 1 000 cycles, with minimal voltage polarization. More impressively, it serves as a competitive self‐supporting electrode in flexible all‐solid‐state ZABs (ASS‐ZABs), achieving 1.49 V open‐circuit voltage (OCV), 106.8 mW cm⁻ ² peak power‐density, and excellent cycling and low‐temperature performance. DFT calculations confirm that the enhanced activity and durability stem from the synergistic effects of heterostructure engineering, selenium vacancy modulation, and conductive carbon integration.