Answer: Electric energy
Voltaic cells use chemical reactions to generate electrical energy, as well as the reverse process.
This type of cell is mainly composed of the anode (a metal electrode where oxidation occurs) and the cathode (a metal electrode where the reduction occurs). These electrodes are placed in two compartments separated by a porous plate or membrane and immersed in a medium containing ions.
This is how, when the chemical reaction of oxide-reduction occurs, electricity is generated.