Mesoscale Transport in Magnetite Electrodes for Lithium-Ion Batteries

Abstract

The mass transport processes occurring within magnetite electrodes during discharge and voltage recovery are investigated using a combined experimental and modeling approach. Voltage recovery data are analyzed through a comparison of the mass transport time-constants associated with different length-scales within the electrode. The long voltage recovery times can be hypothesized to result from the relaxation of concentration profiles on the mesoscale, which consists of the agglomerate and crystallite length-scales. The hypothesis was tested through the development of a multi-scale mathematical model, which showed good agreement with experimental data.