Investigation of Solid State Diffusion Coefficient Dependency in Lithium Ion Battery
Solid state diffusion has been previously demonstrated to vary with temperature and state of charge (SOC) [1-2]. Our simulation shows that it also changes with the current density. While the cell ages, the diffusion coefficient decreases as well. With HPPC (hybrid pulse power characterization) data of power cell at different temperatures and different pulse rates, we estimated the diffusion coefficient dependency on current, as seen in Figure1. Using HPPC data from fresh and aged cell, the diffusion coefficient change with time is also summarized.
1. J.N. Reimers, M. Shoesmith, Y.S. Lin, and L.O. Valoen, 160, A1870-A1884, (2013)