Primary aluminum-air flow battery for high-power applications: Optimization of power and self-discharge

Abstract

Aluminum-air batteries are a front-runner technology in applications requiring a primary energy source. Aluminum-air flow batteries have many advantages, such as high energy density, low price, and recyclability. One of the main challenges with aluminum-air batteries is achieving high power while parasitic corrosion and self-discharge are minimized. In this study, the optimization of an aluminum-air flow cell by multiple-parameters analysis and integration of a four-cell stack are shown. We also studied the incorporation of ammonium metavanadate (NH4VO3) as anticorrosive in 4 mol L-1 KOH electrolyte by discharge and polarization plots. It was concluded that NH4VO3 is an efficient anticorrosive at low currents, but it limits the battery reaction at high-current and high-power applications. Nevertheless, high currents inhibit the corrosion reaction using 4 mol L-1 KOH electrolyte, allowing high power and capacity without anticorrosive additives. The flow in the stack also plays a significant role, and parallel flow is suggested over cascade flow since the latter results in the progressive accumulation of hydrogen as the electrolyte flows through the stack.