Probably meant gradient.

Fun fact, voltage gradient across cell membranes is typically megavolts per meter. At scale that is millivolts per nanometer, but the field strength is the same either way. Membranes are badass.

EDLC's operate at several gigavolts per meter, across a gap only atoms thick. They actually do it the same way as a cell wall -ELD stands for electrostatic double layer- by lining up two sheets of polar molecules, with charges facing each other.