Entropy-Driven Competitive Adsorption Sites Tailoring Unlocks Efficient Hybrid Conversion Zn–Air Batteries

Abstract

Hybrid conversion Zn–air batteries (HC-ZABs) epitomize a typical integrated energy storage and conversion device that advances green chemistry and reduces carbon emissions. However, balancing efficiency and selectivity of electrocatalytic cathodic reactions remains the bottleneck in such batteries. Herein, we address this issue by designing a high-entropy perovskite, La0.6Sr0.1Ca0.1Rb0.1Y0.1CoO3 (HE-LCO), which outperforms conventional perovskites in offering enhanced electrocatalytic activity, better selectivity, and outstanding stability for cathodic benzyl alcohol oxidation reaction (BAOR). Combined spectroscopy characterizations, operando measurements, and theoretic calculations reveal that the entropy-driven modulation of the second coordination sphere in HE-LCO balances the adsorption of nucleophile benzyl alcohol and OH−, while inhibiting competing oxygen evolution reaction (OER). Based on this rationalized HE-LCO electrocatalyst, HC-ZABs realized efficient energy storage and benzoic acid production, boasting a long lifespan of 900 cycles at 20 mA cm−2 and 6.7 mAh cm−2 per cycle. Further, practical ampere-hour-scale HC-ZABs demonstrated a 62.8% energy efficiency improvement and an average benzoic acid yield of 0.85 g per cycle, highlighting the potential of this integrated device for simultaneous sustainable energy storage and green electrochemical synthesis.