An electric field exists in electrical cells responding to potential differences. In non-Faradaic electrochemical cells (no current), interfacial electric fields exist near the surface of charged electrodes where ions gather around and create a double layer in response to an electric field. 100 An electrode surface under the condition of gaining or losing electrons establishes a potential difference concerning the bulk solution. A double layer of charges is created by responding to the compensated ion movement. The magnitude of oriented external electric field can range from 0.3 to 1.0 V Å -1 , and the interfacial electric field on an electrode surface ranges from 0.01 to 0.1 V Å -1 . 100 Understanding the cause of the electrostatic field and possibly quantifying it in an electrochemical cell could be beneficial for optimal catalytic activity.