SEI-related feigned death induced by partial cycling of graphite electrodes in lithium-ion batteries

This article sheds light on an unexpected phenomenon of partial-cycling-induced feigned death in graphite electrodes (coin half cells). The partial cycling within specific voltage windows can trigger rapid but recoverable capacity fading of graphite electrodes. During partial cycling, the extremely rapid capacity fading (up to 80 %) appears in the initial dozens of cycles, and the voltage profile gradually becomes abnormal. Nevertheless, the capacity fading phenomenon can be erased by one full cycling cycle. By combining multiple characterizations (including scanning electron microscope, energy dispersive spectrometer, electrochemical impedance spectroscopy, and X-ray diffraction) with evaluating the influence of the fluoroethylene carbonate additive, it is further confirmed that the partial-cycling-induced feigned death in graphite electrodes is directly related to the composition evolution of solid electrolyte interphase. Meanwhile, a necessary condition for triggering the feigned death is that the lower cut-off voltage is close to the voltage plateaus for LiC18/LiC12transition and LiC12/LiC6transition. Based on these findings, this work provides an in-depth understanding of the cycling performance of graphite electrodes and also presents a challenge for the electrolyte design.