The theories and books all said that in a circuit, electrical current flows out of the positive terminal of a battery, and returns into the negative terminal. However, the new discoveries concluded that, contrary to conventional wisdom, electrons flowed the other direction.
During the discharge of a battery, the current in the circuit flows from the positive to the negative electrode. According to Ohm’s law, this means that the current is proportional to the electric field, which says that current flows from a positive to negative electric potential.
Figure 9.3.3: Charge flow in a charging battery. Figure 9.3.3 illustrates the flow of charges when the battery is charging. During charging, energy is converted from electrical energy due to the external voltage source back to chemical energy stored in the chemical bonds holding together the electrodes.
Many electrical engineers say that, in an electrical circuit, electricity flows one direction: out of the positive terminal of a battery and back into the negative terminal. Many electronic technicians say that electricity flows the other direction: out of the negative terminal of a battery and back into the positive terminal.
Figure 9.3.2: Charge flow in a discharging battery. As a battery discharges, chemical energy stored in the bonds holding together the electrodes is converted to electrical energy in the form of current flowing through the load. Consider an example battery with a magnesium anode and a nickel oxide cathode. The reaction at the anode is given by
During the discharge of a battery, the current in the circuit flows from the positive to the negative electrode. According to Ohm’s law, this means that the current is proportional to the electric field, which says that current flows from a positive to negative electric potential. But what happens inside the battery?