Our findings point to the value of regulating the surface adsorbates at the cathode to control the interfacial nanostructure and consequently the solvent reactivity. This paves a new way for designing "adsorption-type" additives for high-voltage dilute ethers, since there are a huge number of possible surface adsorbates that can be employed to fine-tune the interfacial nanostructure and hence control interfacial electrochemical reactivity. This acquired knowledge extends the understanding of dilute electrolytes and their design, which could be used for a wide variety of electrochemical devices for improved safety (for instance, dendrite suppression in Zn batteries ), controllable reactivity (for instance, enhanced oxygen reduction or weakened water reduction ), or increased selectivity (for instance, CO2 reduction ).