voltage signal necessary to yield a similar C-rate. As a toy example, one can now look at the Li-loss to the SEI for different positions of the superimposed arctan in time as shown in Figure , after a CV step to C/50. This CC step is to ensure that despite the different charge schedules all data shown corresponds to the same SOC (though not charge time). The data suggests that Li-Loss to the SEI can be reduced if the arctan onto the non-linear voltage signal is superimposed at the right potential (roughly 3.75-3.8V). This potential is the chosen example associated with a phase transition/reduction in the NMC811 . With this plot at different C-rates one could start to construct a diagram showing potential ranges to be avoided during charging and, if shifting in potential by C-rate, help to construct a map of C-rate dependent "instability" ranges.