Toward Higher Prelithiation Degree of High‐Capacity Si‐Based Anodes via Physical Vapor Deposition: Impact on Homogeneity and Performance

This study focuses on prelithiation of high‐capacity Si electrodes (11.9 mAh cm −2 ) via physical vapor deposition, where high purity and homogeneity is expected. However, carbonate impurities on freshly deposited Li are shown to be inevitable by means of X‐ray photoelectron spectroscopy. Also, the Li agglomerates do not disappear and insert into Si for higher degree of prelithiation (14%, which corresponds to 432 μg cm −2 ), thus remain on the surface leading to inhomogeneities as proven by scanning electron microscopy and nuclear magnetic resonance spectroscopy. Nevertheless, in LiNi 0.6 Co 0.2 Mn 0.2 O 2 cells, the cycle life of the prelithiated electrodes is improved from 55% to 76% state‐of‐health after 306 cycles.