Lead storage battery is composed of positive plate group, negative plate group, electrolyte and container. The positive plate after charging is brown lead dioxide (PbO2), and the negative plate is gray velvet lead (Pb). When the two plates are placed in an aqueous solution of sulfuric acid (H2SO4) with a concentration of 27% to 37%, the electrode The lead of the plate and sulfuric acid react chemically, and the divalent lead positive ion (Pb2+) is transferred to the electrolyte, leaving two electrons (2e-) on the negative plate. Due to the attraction of the positive and negative charges, the positive lead ions gather around the negative plate, and the positive plate has a small amount of lead dioxide (PbO2) infiltrated into the electrolyte under the action of water molecules in the electrolyte, and the divalent oxygen ions and hydration are combined , So that the lead dioxide molecule becomes a dissociable unstable substance-lead hydroxide [Pb (OH) 4). Lead hydroxide is composed of tetravalent lead positive ions (Pb4+) and 4 hydroxide radicals [4(OH)-]. The tetravalent lead positive ions (Pb4+) remain on the positive plate, making the positive plate positively charged. Since the negative electrode plate is negatively charged, a certain potential difference is generated between the two electrode plates, which is the electromotive force of the battery. When the external circuit is connected, the current flows from the positive pole to the negative pole. During the discharge process, the electrons on the negative plate continuously flow to the positive plate through the external circuit. At this time, the sulfuric acid molecules are ionized into hydrogen positive ions (H+) and sulfate negative ions (SO42-) in the electrolyte under the action of the ion electric field force. , The two ions move to the positive and negative electrodes respectively, and the sulfate negative ions combine with the lead positive ions to form lead sulfate (PbSO4) after reaching the negative plate. On the positive plate, electrons flow in from the external circuit and combine with the tetravalent lead positive ions (Pb4+) to form divalent lead positive ions (Pb2+), and immediately combine with the sulfate anions near the positive plate to form lead sulfate. On the positive electrode.

　　Lead acid batteries use lead plates filled with spongy lead as the negative electrode, lead plates filled with lead dioxide as the positive electrode, and use 1.28% dilute sulfuric acid as the electrolyte. When charging, electrical energy is converted into chemical energy, and when discharging, chemical energy is converted into electrical energy. When the battery is discharged, metallic lead is the negative electrode and undergoes an oxidation reaction and is oxidized to lead sulfate; lead dioxide is the positive electrode and undergoes a reduction reaction and is reduced to lead sulfate. When the battery is charged with direct current, lead and lead dioxide are generated at the two poles. After removing the power source, it returns to the state before discharge to form a chemical battery. Lead storage batteries are batteries that can be repeatedly charged and discharged, called secondary batteries. Its voltage is 2V, usually three lead storage batteries are connected in series, and the voltage is 6V. The car uses 6 lead storage batteries in series to form a 12V battery pack. Lead-acid batteries should be supplemented with distilled water after a period of use to keep the electrolyte containing 22-28% dilute sulfuric acid.