Self-Contained Fragmentation and Interfacial Stability in Crude Micron-Silicon Anodes

The full electrochemical utilization of a crude micron-silicon anode is enabled by a simple and scalable cyclized-polyacrylonitrile (cPAN) electrode architecture paired with an innovative room temperature ionic liquid (RTIL) electrolyte. Field emission scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy show that the resilient cPAN coating mechanically contains the cycling-induced expansion, contraction, and fragmentation of the oversized silicon particles while an electrochemically robust solid-electrolyte interphase (SEI) layer prevents the perpetuation of irreversible side reactions. Prolonged electrochemical cycling data demonstrates unprecedented performance in both half-cell and full-cell configurations. Implementation of the micron-silicon anode constitutes a significant development in the evolution of safe and commercially-viable high-performance lithium-ion batteries. (C) 2018 The Electrochemical Society.