What device generates electrical energy from chemical reactions?

The device that generates electrical energy from chemical reactions is an electrochemical cell. An electrochemical cell harnesses the energy released from chemical reactions, particularly redox reactions, to produce electrical energy. In these cells, a chemical reaction occurs between reactants (often including a conductor, electrolyte, and electrodes), which leads to the flow of electrons and thus generates an electric current.

While a battery is essentially a type of electrochemical cell that stores chemical energy and converts it into electrical energy, the term "electrochemical cell" is more general and encompasses various types of devices that produce electricity through chemical reactions, including batteries. A capacitor, on the other hand, primarily stores electrical energy rather than generating it. Meanwhile, a resistor is a component used to control the flow of electric current in a circuit and does not generate energy.