A high-capacity dual-electrolyte aluminum/air electrochemical cell

Abstract

A novel dual-electrolyte aluminum/air cell (DEAAC), consisting of an aluminum metal anode in an organic anolyte, an anion polymer exchange membrane, and an air electrode in an aqueous alkaline catholyte, has been investigated. The anion membrane separates the organic anolyte from the aqueous catholyte, while allowing hydroxide ions to pass through. The DEAAC exhibited an open circuit voltage (V_OC) of 1.6 V and a short current density (J_SC) of 65 mA cm⁻². With kitchen aluminum foil as the fuel, the DEAAC achieved an anodic capacity of 6000 mA h cm⁻³ at a discharge current density of 30 mA cm⁻², which is much higher than the lithium's theoretical capacity of 2060 mA h cm⁻³. The anodic capacity of the DEAAC increased by 30–50 folds at different discharge current densities compared with that of a traditional alkaline Al/air cell (AAC). Overall, the DEAAC is promising as an electrochemical energy storage device because it has no detrimental hydrogen generation problem and exhibits very high anodic capacity.