Microstructural modeling and design of rechargeable lithium-ion batteries

The properties of rechargeable lithium-ion batteries are determined by the electrochemical and kinetic properties of their constituent materials as well as by their underlying microstructure. In this paper a method is developed that uses microscopic information and constitutive material properties to calculate the response of rechargeable batteries. The method is implemented in OOF, a public domain finite element code, so it can be applied to arbitrary two-dimensional microstructures with crystallographic anisotropy. This methodology can be used as a design tool for creating improved electrode microstructures. Several geometrical two-dimensional arrangements of particles of active material are explored to improve electrode utilization, power density, and reliability of the LiyC6\LixMn2O4 battery system. The analysis suggests battery performance could be improved by controlling the transport paths to the back of the positive porous electrode, maximizing the surface area for intercalating lithium ions, and carefully controlling the spatial distribution and particle size of active material. (C) 2004 The Electrochemical Society.