At present, the development route of power lithium batteries is undergoing a change. Before 2017, the market chose lithium iron phosphate batteries as the mainstream technology, and the requirements of new energy vehicles for battery energy density are a process of continuous improvement, and the industry will continue to change and choose accordingly. The upper limit of the energy density of lithium iron phosphate batteries is about 160Wh/kg. The industry expects that by 2020, the energy density standard of