An in situ constructed Li+-Conductive interphase enables high-capacity and high-rate SiOx/C anode

SiOx/C composites are highly potential anode alternatives for next-generation lithium-ion batteries (LIBs) owing to their low cost and high theoretical capacity. However, the sluggish lithium-ion diffusion kinetics severely limit their practical capacity and rate performance. Herein, a high-capacity and high-rate anode based on commercial SiOx/C is facilely achieved by in situ constructing a Li+ conductive interphase (LCI) to simultaneously boost the transport efficacy of Li+ ions and buffer the volume expansion. The as-designed, LCI-protected SiOx/C anode delivers an exceptionally high capacity of 1420.9 mAh g−1 at 0.2 A g−1, excellent rate performance (91.4% capacity retention from 0.2 A g−1 to 1 A g−1) and long cycling stability, substantially outstripping the pristine SiOx/C counterpart and most recently reported Si-based electrodes. More importantly, taking advantages of the fast and stable lithiation/delithiation processes, this electrode can also be adapted to further applications at large current densities (766.44 mAh g−1 at 5 A g−1) or high mass loadings (5.02 mAh cm−2 at 0.1 A g−1, ∼3.5 mg cm−2). A full battery with satisfactory electrochemical performance is also demonstrated. The strategy of building ion conductive interphase to subtly tailor the transport behavior of Li+ ions is anticipated to unlock the practical deployment of Si-based LIBs.