A Polymeric Coating on Prelithiated Silicon-Based Nanoparticles for High Capacity Anodes used in Li-ion Batteries

Silicon is a promising candidate anode material for lithium ion batteries due to its high theoretical specific capacity of 4,200 mAh g-1 and low discharge potential. However, a high irreversible capacity loss due to a solid electrolyte interphase formation on the surface of Si anodes during the 1st cycle limits its practical applications. Prelithiation is considered an attractive method that can be used to compensate for the active lithium losses during the 1st cycle. Surface oxidation to Li2O when the material comes into contact with moisture and oxygen during electrode fabrication is a main obstacle, leading to poor electrochemical stability. In this work the surface stability of prelithiated Si-based nanoparticles was modified via a polymeric nano-coating method. The results demonstrate that coating with 1-fluorooctane is an effective strategy to mitigate irreversible capacity loss and provide electrochemical stability for high performance next generation lithium ion batteries.