Extension of the Calendar Lifetime of Silicon Anodes With Prelithiation by Thermal Vapor Deposition

Anodes for lithium‐ion batteries utilizing Si nanoparticles have now met critical energy density and cycle lifetime metrics. While their calendar lifetimes have improved due to substantial recent research efforts, the impact of prelithiation on calendar lifetime for advanced Si anodes comprising nanoparticle active material has not been rigorously studied. In this work, prelithiation of Si nanoparticle active material by thermal vapor deposition is explored while assessing the impact of this prelithiation method on electrochemical performance and calendar lifetime. Vapor prelithiation is shown to increase the predicted calendar lifetime as a function of increased prelithiation quantities. This trend is not observed with a systematic increase in prelithiation quantity via electrochemical prelithiation. In addition, the impact of substrate heating on vapor deposition of lithium is explored to provide insight into system‐dependent optimization of the vapor deposition process. As a final result, the shelf life of vapor‐prelithiated anode materials for practical industrial considerations is reported.