VARIABLE DIFFUSIVITY IN INTERCALATION MATERIALS - A THEORETICAL APPROACH

A theoretical approach for estimating a best constant coefficient to u se in an electrode model is presented for the case where experimental data exist on the diffusion coefficient as a function of the state of charge of an intercalation material. this method uses a model of diffu sion in a single particle as its basis. From examining the surface con centration vs. average concentration curve for diffusion in a single p article, we can determine a diffusion coefficient that is a function o f the dimensionless flux rate of material into the particle. This diff usion coefficient function can then be used in a model of a porous ele ctrode.