Fig. 9: Impact of voltage range, C-rate and charging cycle number on energy during charging.

The amount of energy during charging (Ech) depends on the voltage range and the charging rate. As the charging rate increases (from C/4 for cell V4 (a), to C/2 for cell W8 (b), to 1C for W9 (c)), the peak in charging energy shifts towards higher voltage ranges, i.e., [3.675 V - 3.7 V] at C/4, [3.7 V - 3.725 V] at C/2 and [3.825 V - 3.85 V] at 1C.