Wood-derived Fe cluster-reinforced asymmetric single-atom catalysts and weather-resistant organohydrogel for wide-temperature flexible Zn–air batteries

Abstract

Flexible Zn–air batteries are typically constrained by their sluggish oxygen electrocatalysis, unstable electrochemical interface, and consequently restricted operational temperature range. Accordingly, in this work, we propose the fabrication of wide-temperature flexible Zn–air batteries using wood. Specifically, lignin in wood could be converted into Fe-cluster-enhanced asymmetric single-atom catalysts, acting as an air cathode. Additionally, cellulose in wood underwent interpenetrating polymerization with polyvinyl alcohol for the preparation of an organohydrogel electrolyte. The optimized catalyst sample exhibited an exceptional oxygen reduction reaction performance (E_1/2 = 0.9 V) and endowed Zn–air batteries with long-term stability of over 425 h at 20 mA cm⁻². Furthermore, benefiting from the cellulose-based organohydrogel electrolyte, the wide-temperature flexible Zn–air batteries could be cycled stably for over 115 h (5 mA cm⁻²) at 25 °C. In addition, the adaptability of these batteries was explored over a wide temperature range (−60 °C to 50 °C). This approach, i.e., the fabrication of wood-derived wide-temperature flexible Zn–air batteries, holds promise for the preparation of high-performance electrocatalysts and solid electrolytes intended for future energy storage.