Microfabrication-Enhanced Carbon Fiber Cathodes for High Discharge Rate Aluminum-Air Batteries

Aluminum Air batteries (AABs) have one of the highest theoretical energy densities among alkaline electrolyte metal air batteries. However, wide adoption of the high-energy AABs has been hindered by the requirement for expensive platinum-based catalysts as the battery cathode. Herein, a facile process based on either plasma vapor deposition or electrodeposition of silver metal on carbon fiber (CF) cathodes was developed for fabricating high performance and low cost paper cathodes for the AABs. The power performance of the AABs, herein quantified and compared from measured power densities, increased from a base value of 42 mW cm
^-2
of cathode to 80 mW cm
^-2
of cathode by electroplating silver on the carbon fiber surface, and to 150 mW cm
^-2
of cathode by sputtering silver on the carbon fiber surface. The sputtered Ag/CF electrodes have a high power performance at a significantly lower cost than the Pt-based commercial cathode.