Aluminum/Hydrogen/Air Tandem Fuel Cell with Tri-Electrodes

Abstract

Aluminum is a promising energy carrier because of its high theoretical specific energy. Aluminum has long attracted attention as an anode for energy storage and conversion devices. Considerable efforts have been made to develop aluminum/air batteries as energy storage devices given both oxygen and aluminium are readily available and cost-competitive. However, aluminum/air cells using alkaline electrolyte suffer from parasitic hydrogen generation, which severely hinders their development.

Herein, we report a novel passive aluminum/hydrogen/air tandem fuel cell consisting of two anodes and one common air-breathing cathode. The aluminum acts as both the anode for the aluminium/air cell and the source to generate hydrogen for the hydrogen/air cell. By integrating the hydrogen anode into the system, the hydrogen can be utilized as an energy source rather than a waste, which makes the parasitic reaction a beneficial process. The aluminum/air cell has an open circuit voltage of 1.45 V and the hydrogen/air cell of 0.95 V. Overall, the power efficiency of aluminium as a fuel was largely enhanced by 31% after incorporating the hydrogen/air cell.