mV CC cells has a maximum at ~0.3 V (Figure ). This shift indicates formation of a thicker SEI when a CV step is included, which impedes lithium diffusion. Polarization also has a visible effect using a cut-off voltage of 50 mV (Figure ). Both crystalline and amorphous delithiation peaks shift towards higher voltages, and by cycle 75 the peak maxima of a-LixSi are at 0.33 V and 0.31 V for CCCV and CC cycling respectively.