Controllable Interface Engineering for the Preparation of High Rate Silicon Anode

Abstract

Abstract Silicon (Si) is considered to be the promising candidate anode for the next generation of high‐energy‐density batteries. However, the poor initial coulombic efficiency (ICE) and rate performance severely hinder its commercial development. Here, fully exploits the 2D structure of photovoltaic silicon waste (PV‐WSi), combining with the advantage of controllable depositing layers offered by fluidized bed atomic layer deposition (FBALD), to simultaneously achieve high ICE and highrate performance of Si‐based anodes. The characteristic of Li + embedding vertically into the plane direction of the 2D sheet‐like structure of PV‐WSi helps shorten the diffusion distance, alleviating the pulverization problem caused by volume expansion. FBALD is utilized to controllably deposit Li 2 O (≈1 nm) and TiO 2 (≈4 nm) layers to compensate for the loss of Li sources, further suppressing the volume expansion of Si and isolating the side reactions between Si and electrolyte. The prepared Si@Li 2 O@TiO 2 demonstrates ultrahigh ICE (90.9%) and outstanding rate performance (>900 mAh g −1 at a rate of 20 A g −1 ). Full cells with the Si@Li 2 O@TiO 2 anode and LiFePO 4 cathode deliver a stable capacity of 100 mAh g −1 after 300 cycles at 0.5 C. This work provides new ideas for the development of high ICE, high‐rate Si‐based anodes based on low‐cost photovoltaic waste.