A multifunctional biomass-derived cathode enabling high-performance Li-air batteries: Self-catalysis, 3D conduction, and oxygen selection

The progress in energy storage technology has primarily focused on practical applications, necessitating straightforward fabrication, economical materials, and scalable manufacturing. In this work, we demonstrate a facile method to prepare highly self-catalytic cathodes for lithium‑oxygen batteries (LOBs) using bacterial cellulose (BC) as a precursor. The BC-derived cathodes (CBC) retain both the fibrous structure and oxygen-functional groups of the original biomass, producing a material with a modest appearance but outstanding electrochemical properties. The oxygen-functional groups incorporated into the carbon framework exhibit synergistic catalytic effects, enabling an unprecedented discharge capacity of 33,900 mAh g⁻¹ at 200 mA g⁻¹, significantly outperforming most reported cathodes. An integrated oxygen-selective membrane, formed via a facile silicone oil coating process, resulting in stable cycling at current densities up to 1000 mA g⁻¹ and continuous operation for over 240 h in ambient air when coupled with a hybrid polymer electrolyte, highlighting its practical viability. Furthermore, the eco-friendly and self-catalytic CBC represents an innovative “three-in-one” electrode design, simultaneously providing a 3D conductive network, efficient catalytic centers, and selective oxygen transport capabilities, all crucial features for next-generation energy storage systems.