The device that generates current through redox reaction is called primary battery, which can also be said to be a device that converts chemical energy into electrical energy. Some primary batteries can form reversible batteries, while others cannot. When the primary battery is discharged, the negative electrode undergoes an oxidation reaction and the positive electrode undergoes a reduction reaction.
For example, copper-zinc primary battery is also called Daniel battery, and its positive electrode is copper electrode, which is immersed in copper sulfate solution; The negative electrode is a zinc plate immersed in zinc sulfate solution. The two electrolyte solutions are connected by a salt bridge, and the two electrodes are connected by wires to form a primary battery. Usually used dry batteries are made according to the principle of primary batteries.
Both galvanic cells and electrolytic cells are based on redox reactions occurring at the contact interface between electronic conductors (such as metals) and ionic conductors (such as electrolyte solutions).
The history of the invention of the primary battery can be traced back to the end of18th century, when Italian biologist Gavagni was conducting a famous frog experiment. When he touched the frog leg with a metal scalpel, he found that the frog leg would twitch. The famous Volt thinks that this is caused by the current stimulation between metal and frog leg tissue fluid (electrolyte solution).