By Angela Libal, Updated Mar 24, 2022
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Citric acid doesn’t generate electricity on its own. Instead, when it dissolves in water it forms an electrolyte—a solution rich in charged ions that can conduct electric current. The movement of these ions is what enables electrical flow.
In solution, citric acid dissociates into negatively charged anions and positively charged cations. These ions move toward electrodes of opposite polarity: anions drift toward a positively charged metal electrode (anode), while cations migrate to a negatively charged metal electrode (cathode). When the ions reach the electrodes, the anions accept electrons from the positive metal, and the cations release electrons to the negative metal, completing the circuit.
For this process to occur, the two electrodes must be made of different metals—commonly steel and copper—so that a potential difference drives the electron exchange.
