We denote as 𝜎 free c the crticial magnitude of 𝜎 free leading to saturated water polarization. At higher concentrations, 𝐶 dl is higher and 𝜎 free c can be achieved at a smaller potential difference away from the pzc. Hence, we observe that the theoretical peak shifts closer to the pzc at higher concentrations. Contrarily, experimental peaks do not shift when the electrolyte concentration is changed. This discrepancy implies that the 𝐶 dl peak may be not caused by water polarization. Otherwise, it is hard to understand why the magnitude of the peak grows markedly while the potential of the peak is unaltered.