Multi-scale modelling of a LiFePO4 cathode
by
Steven Dargaville
School of Mathematical Sciences, QUT
Coauthors: Dr Troy Farrell

LiFePO4 has recently been gathering considerable attention as a cathodic material for use in Li-ion batteries. The high theoretical capacity (170 mAh/g), thermal stability and low environmental impact of LiFePO4 cells [Padhi et al., 1997, Yamada et al., 2001] offers many potential advantages when compared with existing technologies. We have modelled this using a slightly different approach to that seen in the literature. The established shrinking core model of Srinivasan and Newman [2004] is embedded in a multi-scale model based on that developed by Farrell et al. [2000] for alkaline cells. This approach is suited to LiFePO4 as the material seems to posses up to three distinct size scales, each of which affects the discharge of a LiFePO4 cell. Enhancements to ionic transport must be balanced with electronic; the multi-scale model presented allows us to quantitatively address some of the questions in the literature, regarding transport limitations given various particle and cathode scale parameters.

Date received: November 15, 2009