The frequency vector f = ω/2π used for galvanostatic EIS measurements ranged from 1 × 10 -2 Hz to 3 × 10 5 Hz. The current amplitude was automatically varied to reach a minimum voltage excitation of 10 mV. Each measurement was averaged over two periods and contained 84 logarithmically spaced data points with 12 points per decade, except for the 6 lowest frequency points that were spaced at 6 points per decade. This allowed faster measurements, as the impact of low frequencies on the duration of EIS experiments was dominant.