The potential difference between two half cells in an electrochemical cell is measured by the cell potential, or Ecell. The capacity of electrons to go from one half cell to the other is what determines the potential difference. The Nernst equation is used to determine the concentration of one of the cell's components or to compute the voltage of an electrochemical cell. Ecell = E0cell - (RTnF)InQ is the Nernst formula. Cell potential is ecell. A galvanic cell or voltaic cell is an electrochemical device that transforms the chemical energy of spontaneous redox reactions into electrical energy. electrical cell A voltaic cell is an electrochemical device that produces electricity through chemical processes.