Analysis of Degradation of Si/Carbon||LiNi 0.5 Mn 0.3 Co 0.2 O 2 Full Cells: Effect of Prelithiation

Abstract

© The Author(s) 2019. Published by ECS. Despite considerable progress of silicon/carbon (Si/C) composites anodes, they still suffer from high irreversible capacity losses, which are mainly due to continuous Solid Electrolyte Interphase (SEI) layer formation, which consumes a large amount of lithium. To compensate for the active lithium losses, prelithiation of Si-based anodes has been attempted. In this manuscript, we report the effect of prelithiation on Si/C anodes combined with LiNi0.5Mn0.3Co0.2O2 cathodes in full cell configurations. To prepare LixSi/C anodes, Si/C electrodes were lithiated electrochemically at 0.1 and 0.5 V vs. Li/Li+ in half cell configuration before assembly of the full cell. Special attention is paid to the effect of the degree of prelithiation on initial electrochemical behavior and Li dendrite formation. In this work, electrochemical investigations were performed by using two-electrode and three-electrode measurements. Furthermore, the morphology of the active materials before and after cycling were characterized by post mortem Scanning Electron Microscopy (SEM).