electrode with an agarose frit as a reference electrode (RE). Details about the fabrication procedure of the RE can be found in Papaderakis et al. . Unless otherwise specified, the potential in the experimental data is referred vs. Ag/AgCl(3 M KCl). The electrolyte solutions were freshly prepared within the reported LiCl (BioXtra ≥ 99% from Sigma Aldrich) concentration range and purged with nitrogen prior to use. For the insulating (no added electrolyte) droplet small amounts (within a few μL range) of 1,2-dichlorobenzene (DCB, 99%