Electrolytic cell drive current in opposite directions. The cell with the larger voltage is discharged, making it a galvanic cell, so P is the cathode and N is the anode as described above. But, the cell with the smaller voltage charges, making it an electrolytic cell. In the electrolytic cell, negative ions are driven towards P and positive ions towards N. Thus, the P electrode of the electrolytic cell meets the definition of anode while the electrolytic cell is being charged. Similarly, the N electrode of the electrolytic cell is the cathode while the electrolytic cell is being charged. As already noted,
Electrode potential that only the magnitude expressed according to the convention (2) be called "the electrode potential". To avoid possible ambiguities, the electrode potential thus defined can also be referred to as "Gibbs–Stockholm electrode potential". In both conventions, the standard hydrogen electrode is defined to have a potential of 0 V. Both conventions also agree on the sign of "E" for a half-cell reaction when it is written as a reduction. The main difference between the two conventions is that upon reversing the direction of a half-cell reaction "as written", according to convention (1) the sign of "E" also switches, whereas in