Wood-derived freestanding integrated electrode with robust interface-coupling effect boosted bifunctionality for rechargeable zinc-air batteries

• Published in: Green energy & environment 2024-12, Vol.9 (12), p.1835-1846
• Main Authors: Zhou, Benji, Xu, Nengneng, Wu, Liangcai, Cai, Dongqing, Yu, Eileen H., Qiao, Jinli
• Format: Article
• Language: English
• Subjects: Bifunctional air electrode; Freestanding carbon composite; Interface-coupling effect; Wood biomass; Zinc-air battery
• ISSN: 2468-0257; 2468-0257
• DOI: 10.1016/j.gee.2023.12.002

Fabricating non-noble metal-based carbon air electrodes with highly efficient bifunctionality is big challenge owing to the sluggish kinetics of oxygen reduction/evolution reaction (ORR/OER). The efficient cathode catalyst is urgently needed to further improve the performance of rechargeable zinc-air batteries. Herein, an activation-doping assisted interface modification strategy is demonstrated based on freestanding integrated carbon composite (CoNiLDH@NPC) composed of wood-based N and P doped active carbon (NPC) and CoNi layer double hydroxides (CoNiLDH). In the light of its large specific surface area and unique defective structure, CoNiLDH@NPC with strong interface-coupling effect in 2D-3D micro-nanostructure exhibits outstanding bifunctionality. Such carbon composites show half-wave potential of 0.85 V for ORR, overpotential of 320 mV with current density of 10 mA cm−2 for OER, and ultra-low gap of 0.70 V. Furthermore, highly-ordered open channels of wood provide enormous space to form abundant triple-phase boundary for accelerating the catalytic process. Consequently, zinc-air batteries using CoNiLDH@NPC show high power density (aqueous: 263 mW cm−2, quasi-solid-state: 65.8 mW cm−2) and long-term stability (aqueous: 500 h, quasi-solid-state: 120 h). This integrated protocol opens a new avenue for the rational design of efficient freestanding air electrode from biomass resources. [Display omitted] •Activation-doping assisted interface construction strategy is achieved in fabricating wood-derived integrated air electrode.•Interface coupling effect bestow superior catalytic properties on integrated air electrode.•The finely modulated electrode hydrophilicity ensures triple-phase boundary formation to accelerate mass transfer.•The obtained CoNiLDH@NPC exhibits remarkable bifunctional activity with potential gap of 0.70 V.•Zinc-air batteries based on CoNiLDH@NPC plate show superb performances in peak power density and cycling life.