Performance modeling and parameter sensitivity analyses of an aluminum-air battery with dual electrolyte structure

A numerical model is created to simulate the performance of an aluminum-air battery (AAB) cell with a dual electrolyte structure and the simulation results of discharge voltage and power density at varying current density are validated with the experimental measurements from a home-made battery cell. The resistance due to the formation of passivation film on the aluminum anode is modeled as a resistive film in the numerical model. After estimating the performance of originally designed battery cell, the effect of model parameters on the battery performance is scrutinized by adjusting the parameter values within a suitable range. The simulation results demonstrate that the passivation film on the aluminum anode strongly deteriorates the battery performance. If the resistance of the passivation film is diminished to 25% of the original one, the open circuit voltage increases to 1.5 V which can compete with the AAB with pure alkaline electrolyte. The thickness of dual-electrolyte is an important factor, which strongly increases the discharge power density and the corresponding current density as it decreases. The OH concentration, partial oxygen pressure, different catalysts, thickness and active specific surface area of the catalyst layer also show a secondary role in performance improvement, but a trade-off needs from the economic perspective. Finally, a linear regression method is employed to analyze the sensitivity of five model parameters to the battery performance and the relative importance is revealed.