Electrochemical Prelithiation of Self-Standing Mesoporous Silicon Film Anodes for Enhanced Si || NMC Full-Cell Performance

This study identifies the optimal electrochemical prelithiation conditions for a self-standing silicon (Si) film anode to enhance performance when paired with a nickel manganese cobalt (NMC) cathode in a full cell. Through a combination of imaging, spectroscopy, and electrochemical analyses, the research demonstrates that a prelithiation level of 3000 mAh g-1 effectively minimizes cracking in the Si film, leading to superior battery performance. X-ray photoelectron spectroscopy analysis reveals a prelithiated interphase composed of lithium silicates, Li2O, Li₂CO3, and LiF, which contribute to low solid electrolyte interphase resistance and charge transfer resistance, thereby improving cycling stability. The full cell with the optimally prelithiated Si anode achieves an initial specific discharge capacity of 143 mAh g-1 and an initial coulombic efficiency (ICE) of 89% at 0.02 C, with 91% capacity retention after 50 cycles at 0.1 C. These findings indicate a marked improvement in ICE, specific capacity, and cycling stability compared to non-prelithiated Si film electrodes, bringing the full cell's performance close to that of an NMC half-cell.