Effects of lithium fluoride coating on the performance of nano-silicon as anode material for lithium-ion batteries

To overcome the capacity fading issue of Si particle upon repeated cycle process, in this study, lithium fluoride (LiF) is introduced to coat commercial nano silicon to form an artificial solid electrolyte interface (SEI) film. After a facile spray drying process, Si nanoparticles are aggregated to form spheres and the LiF is homogenously coated on the surface of Si nanoparticles. Compared with the bare nano-Si, Si/LiF composite shows a huge increase in capacity retention, increasing from 0.8% to 31.2% after 30 cycles. Such improvement results from artificial formation of a stable LiF-based SEI film on the Si surface, reducing the parasitic reaction and thus minimizing the capacity loss during the first lithiation process. (C) 2016 Elsevier B.V. All rights reserved.