With the increasing global demand for sustainable energy, new energy lithium batteries, as key components in fields such as electric vehicles and energy storage systems, have seen a rise in research focusing on their performance and safety improvements. Aerogel, a material with a unique nano-porous structure, demonstrates broad application prospects in the field of new energy lithium batteries due to its excellent properties such as heat insulation, flame retardancy, and lightness. 
I. Basic Characteristics of Aerogels 
Aerogel is a nanoscale porous solid material obtained through the sol-gel method and treated by supercritical drying technology. It has an extremely low density and is one of the lightest solid materials in the world, even lighter than the density of air. The high porosity and high specific surface area of aerogel make it have excellent adsorption and insulation properties. Its thermal conductivity is extremely low, ranging from 0.012 to 0.024 W/(m·K), which is 2 to 3 orders of magnitude lower than that of traditional insulation materials. 
Compared with traditional insulation materials, the insulation performance of silica aerogel insulation board is 2 to 8 times that of traditional materials. Therefore, with the same level of insulation effect, the amount of aerogel used is less. 
Take the pipe as an example. If a pipe with a diameter of 150mm needs to achieve the same insulation effect, the thicknesses of the corresponding insulation materials - expanded perlite, calcium silicate, rock wool, and aerogel felt - would be 90mm, 76mm, 64mm, and 20mm respectively. 
II. Application of Aerogel in New Energy Lithium Batteries 
Heat insulation and flame retardancy 
During the charging and discharging process of new energy lithium batteries, a large amount of heat is generated. If this heat cannot be effectively dissipated, it may cause thermal runaway and even lead to battery explosion. Aerogel, due to its excellent heat insulation properties, is widely used in the heat insulation protection of lithium batteries. By setting aerogel insulation layers between battery cells, between modules, and between the battery box and the passenger compartment, the transmission path of thermal runaway can be effectively blocked, reducing the risk of thermal runaway spread. In addition, aerogel also has excellent flame retardancy, which can maintain structural stability in high-temperature environments and prevent the spread of fires. 
2. Increase the energy density of the battery pack 
To enhance the range of electric vehicles, the improvement of battery pack energy density is crucial. Aerogel outperforms traditional materials in terms of heat insulation, and it is lightweight and thin, which can reduce the material usage while maintaining the insulation performance. According to research, using aerogel materials can reduce the thickness and weight by 3 to 8 times while ensuring the same insulation effect. This is of great significance for improving the overall energy density of the battery pack. 
3. Thermal insulation in low-temperature environments 
In low-temperature environments, the performance of lithium batteries will significantly deteriorate and may even fail to function properly. Aerogel, due to its outstanding heat insulation properties, can effectively solve the insulation problem of lithium iron phosphate batteries in low-temperature conditions, ensuring that the batteries can still charge and discharge normally in cold weather, thereby enhancing the applicability and reliability of electric vehicles.