Bio‐Derived Wood‐Based Gas Diffusion Electrode for High‐Performance Aluminum–Air Batteries: Insights into Pore Structure

Abstract

Abstract Gas reactant transport plays a crucial role in various gas‐consumption reaction‐based electrochemical devices, but the pivotal performance limitation still centers on gas diffusion electrodes (GDEs). To this end, natural cross‐cut wood to prepare GDEs for aluminum–air batteries is introduced by utilizing the ordered structure with microchannels. With cobalt–nitrogen co‐doped carbon nanotubes as the oxygen reduction reaction catalysts grown inside the channels of carbonized wood slice and wettability gradient modification, cherry‐based GDE achieves higher power density (267 vs. 236 mW cm−2) than the commercial carbon fiber paper‐based electrode. By bridging the identified characteristics of pore structure via deep‐learning image recognition technology with the permeability of other three typical kinds of (ash, pine, and oak) wood‐based GDEs, it is revealed that the ratio of effective porosity to the average pore size is key to the performance. This work demonstrates the feasibility of bio‐derived wood‐based materials for fabricating high‐performance GDEs and provides insights into pore structure for the rational design of structured electrodes.

Keywords

• aligned vertical pore structure
• gas diffusion electrodes
• metal–air batteries
• wettability gradient
• wood‐based