Secondary current density distribution analysis of an aluminum–air cell

Secondary current density distributions in a parallel two-plane Al/air cell and a wedge shaped Al/air cell were analyzed. The parameters studied include the entrance effect, the activity of the cathode, the cell gap and the extension of the cathode. The entrance effect disappears at about a one to two cell gap from the entrance. The activity of the cathode has a large effect on the local current density. With increases in the cell gap, the average current density decreases, but the peak current density over the average current density increases. By extending the cathode below the anode, the high local current density can be reduced. In a wedge shaped Al/air cell, the planar portion of the anode enters the cell. As the anode is consumed, the top portion of the anode is consumed faster because of the decreased cell gap and increased reaction rate. The anode adapts to be parallel to the cathode in the cell. A FEMLAB (finite element method) package was used for all the calculations.