An investigation of parameters affecting the apparent chemical diffusion coefficient in composite electrodes in solid-state cells

A theoretical analysis of composite electrodes consisting of a mixture of an intercalation host and a solid electrolyte has suggested that the effective ionic conductivity of the latter should directly influence the apparent chemical diffusion coefficient of the electroactive species in the electrode. This investigation has measured the dependence of the apparent chemical diffusion coefficient on the particle size, electrode composition and electrode thickness of a model composite electrode consisting of niobium disulphide with a range of silver ion conducting glasses. The theoretical model is validated to a limited extent and deviations are ascribed to the predominant influence of diffusion in the host particles.