Briefly describe the difference between lithium-ion batteries and lead-acid batteries for electric vehicles

Lead-acid batteries are composed of a positive plate (lead dioxide PbO2) and a negative plate (sponge pure lead Pb) immersed in an electrolyte. The electrolyte is an aqueous solution of sulfuric acid (H2SO4). When the battery and the load are connected and discharged, both the PbO2 on the positive plate and the Pb on the negative plate become PbSO4, the H2SO4 in the electrolyte decreases, and the relative density decreases. When charging, change in the opposite direction: PbSO4 on the positive plate is reduced to lead peroxide PbO2; PbSO4 on the negative plate is reduced to velvet Pb; sulfuric acid in the electrolyte is added, and the relative density becomes larger. If the complex chemical reaction process is omitted, it can be expressed by the following formula: charging PbO2+Pb+2H2SO4? 2PbSO4+2H2O positive and negative electrolyte discharge positive and negative electrodes (1) The structure of the positive plate of the positive plate is that the grid is filled with lead paste , The grid is an alloy of lead, and the important components of the lead paste are α lead dioxide PbO2 and β lead dioxide PbO2 after being processed and used. (2) Negative plate The structure of the negative plate is also filled with lead paste in the grid. The important component of the lead paste is spongy (fluffy) pure lead Pb after being processed and used. During normal charging and discharging, the materials participating in the electrochemical reaction on the positive and negative plates are collectively referred to as active materials, the positive electrode mainly refers to PbO2 and PbSO4, and the negative electrode mainly refers to pure lead Pb and PbSO4. (3) Separator Separator is an important component of lithium-ion batteries for electric vehicles, and is not an active material. The separator itself is a porous insulating material, and the electrolyte can pass through it smoothly. The important purpose of traditional separators is to prevent short-circuiting of the positive and negative plates. Since the appearance of fine glass fiber separators (AGM), the performance of lead-acid batteries has been improved, and they have been widely used to seal valve-controlled batteries. The thin glass fiber separator has the functions of preventing short-circuit of the positive and negative plates, absorbing and storing electrolyte, and supplying oxygen channels. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.