An environmentally degradable Al–air battery to realize future green energy–matter flow

Abstract

The effective utilization of green electricity contributes to mitigating environmental pollution associated with traditional fossil fuels. However, some components of most existing energy conversion systems continue to exert adverse environmental impacts, such as the heavy metal catalysts and fluorine-containing ionomers of fuel cells. Therefore, an environmentally friendly energy–matter flow driven by green electricity, achieved through a specially designed degradable Al–air battery as the energy conversion system, was proposed in this work. The degradable Al–air battery pack, incorporating both a degradable poly(NBE-co-Hemin) catalyst and a degradable hydrogel electrolyte, can carry a maximum energy density of 1022.4 W h kg⁻¹. Notably, when the designed battery is disposed of in the environment, the catalyst and the hydrogel electrolyte can be degraded naturally into small molecules and inorganic salts. The designed Al–air battery demonstrated a peak power density of 205.1 mW cm⁻² and a prolonged discharge time at a high current density, significantly surpassing the performance of previously reported sustainable Al–air batteries. The proposed energy–matter flow, with the designed degradable Al–air battery serving as the key energy converter, can establish a sustainable and advanced pathway for green electricity utilization in the future.