Quantifying the Influence of the Electrode Porous Structure on Lithium-Ion Battery Performance

Abstract

The growing demand of lithium-ion batteries (LIBs) on portable electronics, electric vehicles urgently requires higher energy density, longer cycling life, and better safety to satisfy the needs of environmental factors and economics. In order to have higher energy density, simply increasing the volume of the single electrodes of LIB results in poor capacity due to inefficient mass transport of Li ions through the irregular microstructure of the electrode. Since understanding the influence of geometrical properties electrodes is of considerable significance to battery performance, we investigate two basic cells: (i) an irregular microstructure intercalation host and (ii) a periodically aligned microchannel intercalation hosts. Our in-house developed simulation tool solves Nernst-Planck and electron conduction equations with proper interfacial reactions by considering experimentally verified ageing mechanism (2-layered SEI and lithium-plating) into account and compute the associated characteristic voltage vs. state of charge curves under various geometric and design parameters. The proposed model is parameterized and optimised for mass transport based on fresh cell and validated against experimental results available on the literature. We show that the nanostructured electrode design yields better battery performance because the uniformity of electrodes yields elimating the nonuniform intercalation and side reactions on active material electrode surface. This work presents a design concept for higher energy and power densities that are not limited to LIBs.*This work has been supported by The Warwick Research Development Fund, UK, through the Grant No. RDF19035. Figure 1