Optimization of air cathode composition for enhanced performance in aluminum-air batteries

Aluminum-air batteries are a promising energy storage system due to their high theoretical energy density, environmental friendliness and cost efficiency. However, practical applications are limited by poor oxygen reduction reaction efficiency at the air cathode. While extensive research focused on catalyst to enhance the efficiency, limited studies have explored optimizing air cathode material compositions to maximize the electrochemical performance. This study aims to address this gap by formulating and optimizing an air cathode. A three-level Taguchi method was employed to systematically design experiments, optimizing carbon black, activated carbon, and manganese dioxide mass ratios first, followed by polytetrafluoroethylene and propanol ratios. The electrochemical performance was evaluated using linear sweep voltammetry and discharge tests. Grey Relational Analysis was utilized to analyze the electrochemical performance and rank the cathode formulations based on key performance parameters such as peak power, limiting current, discharge time and plateau voltage. The results indicated that the optimal mass ratio of carbon black:activated carbon black:manganese oxide is 9:1:2, while the optimal polytetrafluoroethylene: propanol mass ratio is 1:3. The optimized air cathode achieved a peak power of 137 mW at 1.5 V, more than doubling the performance of the unoptimized air cathode, which generated only 66 mW at 0.7 V. © 2025