New energy vehicles represented by "Tesla" and "BYD" use lithium battery groups with nominal voltage of 400~600V as power supply, but lead-acid battery is still an indispensable component of new energy vehicles. The 12V low-voltage starting power supply composed of lead-acid batteries plays the following important roles: power supply to low-voltage electrical accessories (ignition switch, internal and external lighting control, remote key, central door lock control, horn, defrosting, doors, wipers, various sensors, etc.); Wake up the high pressure power system; As a safe backup energy source. The low-voltage system of new energy vehicles puts forward high requirements on the air permeability index of the AGM partition in the on-board lead-acid battery, which increases the air permeability index to more than 2 times of the traditional standard, so as to optimize the charge-discharge performance, enlarge the battery capacity, and significantly improve the battery life. While greatly improving the air permeability, it is necessary to maintain the original AGM partition with uniform thickness, high strength, good acid absorption and other excellent properties, so as to ensure that the battery can provide stable voltage and current for many electronic and electrical components in low temperature, high temperature and various complex working conditions, support deep discharge, cooperate with intelligent charging strategy, and improve the energy efficiency of lithium electricity to a greater extent.