The discharge behaviour of the zinc/air slurry cell

Abstract

Summary The discharge capacity of a zinc/air cell with a zinc slurry anode has been measured in potassium hydroxide electrolyte, with and without the addition of potassium silicate solution. In a narrow range of compositions around 3 mol l−1 potassium hydroxide, there is a large increase in discharge capacity, similar to that observed previously with a solid zinc electrode. The increase in discharge capacity by the addition of silicate ions appears to arise from the formation of a layer around the zinc particles (analogous to an electropolishing layer) by the adsorption of silicate ions. The addition of lithium ions also increases the discharge capacity, but this seems to occur by another mechanism probably involving the stabilization of micelles.