What happens inside a battery when it produces electricity?

Inside a battery, chemical reactions at two electrodes drive the movement of charged particles. At the negative electrode (anode), a chemical oxidation reaction releases electrons. These electrons cannot travel through the electrolyte inside the battery, so they flow through the external circuit as electric current. At the positive electrode (cathode), a reduction reaction absorbs those electrons, completing the circuit. Meanwhile, ions move through the electrolyte between the electrodes to balance the charge internally. In a common alkaline battery, zinc at the anode gets oxidized while manganese dioxide at the cathode gets reduced. This continues until the chemical reactants are consumed. In rechargeable batteries, applying external current reverses these reactions, restoring the original chemicals.