(Invited) Calendar Life Analysis of Si-Containing Anodes for Li-Ion Batteries

Because of their high-gravimetric capacities, the use of Si-containing anodes in Li-ion batteries can lead to a large jump in energy densities. However, the calendar life of these Si containing batteries is poor because of the highly reducing chemical reactivity of lithium silicides at high states of charge (SOC) as well as other factors posing challenges for future life estimation and those attempts to extend lifetime. Lithium consumption through loss of inventory to solid electrolyte interphase (SEI) growth (and re-growth), and potential impedance increase through loss of active material contributes greatly to the shortened calendar life; typically on the order of one year to 80% energy retention. The US Department of Energy (DOE) has established a program (the Silicon Consortium Project or SCP) that currently is confronting the basic and applied science problems of Si with the hopes of developing >10 year calendar life for Si-containing cells. In this presentation, I will discuss these issues and provide some solutions to partly solve the short calendar life of Si together with models to estimate the future life.