Morphological changes in and around Sn electrodes during Li ion cycling characterized by in situ environmental TEM

Sn electrodes are cycled against Li metal in situ in a transmission electron microscope in commercial liquid electrolyte. The strain associated with the dealloying reaction is accommodated by the formation of nanoscale porosity. Significant asymmetry in the charge vs. discharge rate results from the effects of solid–electrolyte interphase formation in the confined geometry during lithiation. This layer partially dissolves during delithiation. This cyclic formation and dissolution of solid–electrolyte interphase should contribute significantly to the capacity fade observed in Sn-based electrodes.

Morphological evolution of Sn anode grains during delithiation.Figure optionsDownload high-quality image (289 K)Download as PowerPoint slide