Investigation on capacity extension through non-uniform anode microstructure in lithium-ion battery

Abstract

Capacity fading is one major problem that hinders predicting the state of health and optimal use of the Li-ion battery in various applications, viz., electric vehicles and consumer electronic devices. In this work, the importance of non-uniform anode microstructure and its implications on capacity fading characteristics are examined. The numerical study considers the effect of anode particle size distribution, geometry, and tortuosity on capacity fading at different current densities. Our investigation reveals that the capacity fade mechanism is the least when the particle size is small near the anode-separator interface. The study on the effect of the geometry of particles shows that capacity fading is the least when spherical particles are employed. A separate study on the effect of tortuosity reveals that capacity fading decreases with the decrease in tortuosity. Further, a substantial interaction between particle size distribution and microstructural characteristics is reported for the cycle. Additionally, the role of anode microstructure is evident in charging compared to discharging. Moreover, the fading characteristics are prominent at higher current densities. These study insights establish that the anode non-uniform microstructure affects the cell performance and capacity fading characteristics that can ultimately improve the reliability aspect and increase the value of the battery.