A new single-particle model to evaluate the Li-ions diffusion coefficients of LiMn1-xFexPO4

It remains a challenge to evaluate the Li-ions diffusion coefficients of LiMn1-xFexPO4 due to the presence of two voltage platforms upon charge/discharge. In this paper, a new single-particle model based on Butler-Volmer (BV) equation and one-dimensional diffusion equation is established. Using this model, the cyclic voltammogram curves of LiMn1-xFexPO4 single-particle electrodes are successfully fitted and their Li-ion diffusion coefficients in organic electrolyte are obtained. Through analyzing the diffusion coefficients, it is found that the Li-ions diffusion coefficients for both Fe and Mn redox processes in LiMn1-xFexPO4 reach the maximum when x = 0.4. In addition, the values for oxidation processes are much larger than those for reduction processes.