Voltaic(galvanic) cells
Voltaic (galvanic) cells are electrochemical cells that generate electrical energy from spontaneous redox reactions. They consist of two half-cells, each containing an electrode and an electrolyte solution. The electrodes are usually made of different metals or metal compounds and are connected by a wire that allows for the flow of electrons. The electrolyte solutions can be aqueous or non-aqueous and contain ions that participate in the redox reaction.
In a voltaic cell, one electrode undergoes oxidation (loses electrons) while the other undergoes reduction (gains electrons). The electrode that undergoes oxidation is called the anode, while the electrode that undergoes reduction is called the cathode. Electrons flow from the anode to the cathode through the wire, creating a flow of current.
The direction of electron flow in a voltaic cell is from the anode to the cathode, which is opposite to the direction of the flow of ions in the electrolyte. This creates a separation of charge that leads to the generation of an electric potential difference, or voltage, between the two electrodes. The voltage of a voltaic cell depends on the specific redox reaction and the concentrations of the ions in the electrolyte.
Voltaic cells are used in many applications, including batteries for portable devices, power sources for electrical vehicles, and backup power systems for buildings. They are also used in electroplating, where a thin layer of metal is deposited on a substrate by using a voltaic cell.