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,
Polarograph Polarograph A Polarograph is a chemical analysis instrument used to record automatic voltage-intensity curves. The Polarograph uses an electrolytic cell consisting of an electrode or microelectrode small area, generally of mercury drop type , which is a very fine capillary tube through which mercury flows slowly , which comes in the form of small droplets, which fall on the same surface of a much broader element, which is the other electrode . When one applies a variable voltage in this cell, the electrode large area remains unchanged, while the microelectrode undergoes a change of potential ,( i.e. is polarized). It