Eco-Sustainable Aluminum-Air Batteries

Aluminum-air batteries are energy conversion devices considered to be promising alternative to lithium-ion batteries due to their high theoretical energy density as well as the easy availability and recyclability of the anode material. The use of neutral water-based electrolytes and raw materials of natural or synthetic but biodegradable origin in the battery components, mainly electrolytes and cathodes, adds further advantages of safety, affordable costs and eco-friendliness. In this work, the electrochemical performance of aluminum-air batteries assembled with gel polymer electrolytes, made of natural polysaccharides and saline aqueous solutions, was investigated and discussed, through comparing the results obtained using cathodes based on platinum catalyst with respect to those based on a cheaper wood-derived activated carbon. Three-electrodes discharge measurements, rate performance tests, polarization and power density curves, and linear sweep voltammetry measurements were used to critically compare different cathodic materials used in combination with neutral electrolytes. The results show that the best electrochemical performances were obtained for aluminum-air cells assembled with wooden biomass-derived air cathodes.