An electrochemical cell includes a container at atmospheric pressure comprising a liquid electrolyte and a first electrode at least partially immersed in the electrolyte. A plasma source is spaced apart from a surface of the electrolyte by a predetermined spacing, and a plasma spans the predetermined spacing to contact the surface of the electrolyte. A method of operating the electrochemical cell entails providing a first electrode at least partially immersed in a liquid electrolyte and producing a plasma in contact with a surface of the electrolyte at atmospheric pressure. The plasma acts as a second electrode, and a current is generated through the electrolyte. Electrochemical reactions involving at least the second electrode are initiated in the electrolyte.