Charges and their transport are integral to the function of electronic devices, batteries, and biological systems. The charges that accumulate at the interface between a solid electrode and an electrolytic solution containing ions that carry charges can affect the electrode-electrolyte interaction as well as processes such as corrosion and molecular adhesion. Consequently, it is important to obtain a clear picture of accumulated charges at such interfaces to improve our understanding of interfacial phenomena in a variety of systems. However, imaging the three-dimensional (3-D) spatial distribution of accumulated charges at interfaces has been difficult because it is challenging to measure the lateral charge distribution at a solid-liquid interface.