Graphitic Nitrogen Regulates Chloride Utilization for Oxygen Reduction in Ampere‐Level Seawater‐Based Zinc‐Air Batteries

ABSTRACT

The Cl ⁻ ‐rich environment of seawater poses a persistent challenge to oxygen reduction reaction (ORR) in seawater‐based zinc‐air batteries (S‐ZABs). Although considerable progress has been made in mitigating Cl ⁻ ‐induced degradation, strategies that utilize Cl ⁻ for beneficial interfacial regulation remain underdeveloped. Herein, we develop a graphitic‐N‐rich N‐doped carbon catalyst (denoted as N _Gr ‐HCS‐1000) that transforms Cl ⁻ from a poisoning species into an ORR promoter. In situ and quasi‐in situ spectroscopic analyses, together with theoretical calculations, reveal that graphitic‐N sites with relatively positive electronic character preferentially adsorb Cl ⁻ , thereby inducing local charge redistribution at adjacent carbon active sites. This Cl ⁻ ‐utilization strategy optimizes the electronic structure of the carbon active sites and balances the Gibbs free energy (ΔG) of ORR‐related intermediates, placing N _Gr ‐HCS‐1000 near the volcano apex defined by ΔG _*OOH and η _ORR . Consequently, N _Gr ‐HCS‐1000 achieves a high half‐wave potential of 0.92 V in seawater‐based electrolyte, 50 mV higher than that in the deionized‐water counterpart. The N _Gr ‐HCS‐1000 further endows aqueous and solid‐state S‐ZABs with stable operation over a wide temperature range from −40°C to 60°C, while delivering a capacity of 6.95 Ah and an output power of 1.56 W in ampere‐hour‐scale S‐ZABs. This work highlights Cl ⁻ utilization as an effective strategy for enhancing ORR in seawater electrolytes.