Electrolytic cell reaction which would not occur spontaneously otherwise. A galvanic cell can be considered an electrolytic cell acting in reverse. While electrolytic cells convert electrical energy into chemical energy, galvanic cells convert chemical energy into electrical energy. Galvanic cells are often used in batteries. Michael Faraday defined the cathode of a cell as the electrode to which cations (positively charged ions, like silver ions Ag) flow within the cell, to be reduced by reacting with electrons (negatively charged) from that electrode. Likewise he defined the anode as the electrode to which anions (negatively charged ions, like chloride ions Cl) flow within
Silver chloride electrode chloride is a popular choice of biological electrodes due to its low half-cell potential of approximately 220 mV and the lower of the impedance of the electrode by silver chloride. When appropriately constructed, the silver chloride electrode can be used up to 300 °C. The standard potential (i.e., the potential when the chloride activity is 1 mol/kg) of the silver chloride electrode is a function of temperature as follows: Bard et al. give the following correlations for the standard potential of the silver chloride electrode between 0 and 95°C as a function of temperature (where t is temperature in °C):