Bamboo-derived aerogel with atomically dispersed Co as a high-performance bifunctional electrocatalyst for durable zinc-air batteries

Abstract

The development of highly efficient and durable bifunctional electrocatalysts is crucial for rechargeable zinc-air batteries, which have garnered significant attention as a promising sustainable energy storage technology. Herein, a novel Co-N-C-1050 catalyst is synthesized using a high-temperature gas transport method, where high purity cobalt powder and bamboo biomass aerogel are treated with ammonia gas at 1050 °C. The resulting catalyst exhibits a 3D interconnected porous network composed of dense carbon fibers, which atomically dispersed Co, N, and C elements are uniformly distributed. The synergistic integration of highly active Co single atoms and N-doped 3D carbon fiber aerogel enables Co-N-C-1050 to demonstrate excellent bifunctional electrocatalytic performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), comparable to commercial Pt/C and RuO₂ catalysts. This catalyst has a half-wave potential of 0.842 V for ORR and a potential of 1.472 V at 10 mA cm⁻² for OER, outperforming N-C-1050 and benchmark catalysts. A zinc-air battery is driven by Co-N-C-1050 achieves a high power density of 135 mW/cm² and exceptional stability over 138 h of charge/discharge cycling, surpassing the higher-cost Pt/C + RuO₂ catalyst. This biomass aerogel based single-site Co-N-C catalyst offers a promising approach for developing high-efficiency and long-cycle-life zinc-air batteries.