Communication-Effect of Lower Cutoff Voltage on the 1st Cycle Performance of Silicon Electrodes

Silicon electrodes were cycled once to determine the effect of lower cutoff voltage (LCV) on the irreversible capacity and Li15Si4 phase presence for a protocol that incorporated a potentiostatic hold at the LCV. Cells lithiated below 90 mV showed indications of the crystalline Li15Si4 peak, which was absent for cells with lower cutoff voltages above 90 mV. Irreversible capacity loss was independent of the LCV used. While higher LCVs led to lower capacities, this capacity could be recovered with longer potentiostatic holds. These longer holds did not lead to Li15Si4 formation. (C) 2019 The Electrochemical Society.