Evaluation of Electrochemical Interface Area and Lithium Diffusion Coefficient for a Composite Graphite Anode

A structural model to calculate the electrochemical interface area for a composite graphite electrode is described. A new equation using the model predicted area to calculated chemical diffusion coefficient ( D Li + ) eliminates the effects from fabrication such as active mass ( m B ) and geometric area ( S Geo ) . The chemical diffusion coefficient values calculated for graphite electrodes of different thicknesses and porosities using the new equation are almost the same as expected. The values of D Li + in the graphite vary between 10 − 11.9 and 10 − 9.9 cm 2 / s over the course of the lithium deintercalation in the graphite samples.