The overwhelming pre-sales of the Tesla Model 3 have once again focused attention on new energy vehicles, and its significance for the lithium battery industry lies in the new power battery materials it employs. The Model 3 battery technology reportedly uses a silicon-carbon anode, achieving an energy density of 300Wh/kg and a range of approximately 346 kilometers. This improved range is attributed to the significantly higher specific capacity of silicon compared to graphite, and specific capacity directly reflects the amount of electricity generated per unit weight of battery.
Currently, the theoretical specific capacity of graphite anode materials used in the market is 372 mAh/g, while the theoretical specific capacity of silicon-carbon composite materials is approximately 4200 mAh/g, more than 10 times higher than that of graphite anodes. The high capacity of silicon-carbon anode materials can fully meet the energy requirements of pure electric vehicle batteries. However, the huge volume expansion effect generated during the charging and discharging process of silicon-based lithium-ion batteries makes their industrialization difficult. The application of silicon-carbon anodes in the Model 3 battery technology is a significant breakthrough in the industrialization of silicon-carbon anode materials. It is reported that this anode material incorporates 10% silicon, achieving an energy density of 300 Wh/kg. With technological advancements, silicon-carbon anode materials are expected to further improve lithium battery capacity. Inorganic silicon materials (using silicon or silicon suboxide as the anode) make a significant contribution to lithium battery capacity. So, can another important member of the silicon material family—high-performance organic silicon materials—also contribute to the range of new energy vehicles?
Organosilicon has a Si-O bond main chain structure, with side chains connected to various organic groups via silicon atoms. The bond energy of the Si-O bond in organosilicon is much greater than that of the C-C bond, resulting in high thermal stability; the chemical bonds of the molecules do not break or decompose under high temperatures (or radiation irradiation). It is resistant to both high and low temperatures and can be used over a wide temperature range. Furthermore, the main chain lacks double bonds, making it resistant to decomposition by ultraviolet light and ozone. This unique composition and molecular structure endow organosilicon with the functions of both organic and inorganic materials, exhibiting excellent high and low temperature resistance, weather resistance, electrical insulation, and biocompatibility. Organosilicon materials are widely used in construction, electronics, chemical engineering, and other civilian applications, and even in specialized, cutting-edge, and specialized technical fields. For example, they exhibit excellent properties even in extreme conditions such as outer space or the extreme cold and heat of Siberia or the Sahara.
Temperature control
The carbonate in lithium-ion battery electrolytes has a high melting point. Generally, the battery cannot function properly when the temperature is below -20°C; when the temperature is too high, the battery separator will melt, causing a short circuit and potentially leading to battery fires and other safety issues. Only by maintaining a suitable temperature can the battery achieve its optimal performance. Dow Corning's customized silicone materials can effectively dissipate heat for the battery pack and cells, improving the battery's operating temperature. Simultaneously, the dispensable fluid silicone can form a thermal shield around the battery cells, allowing the battery to maintain high efficiency even in excessively cold or hot environments.
Durability
During daily use of new energy vehicles, moisture can cause lithium hexafluorophosphate in the battery to decompose and produce HF, and vibration can cause the tabs to break, leading to short circuits. These common factors can all affect battery life. To address this, Dow Corning offers a "customized" silicone solution for battery packs, safeguarding battery durability.
Insulation
Another challenge facing electric vehicle batteries is short circuits and overcurrent, and the insulating properties of silicone materials are perfectly suited to address this issue. Applying silicone to batteries effectively protects critical internal electronic components, cells, and busbars, thereby preventing the risks of power surges and battery fires.
As the power source for new energy vehicles, batteries are affected not only by raw materials such as cathode materials, anode materials, separators, and electrolytes, but also by factors such as temperature changes, vibrations, and humidity during vehicle operation, which alter battery performance and consequently affect driving range. Scientists have conducted extensive research on the application of organosilicon in new energy vehicles, and Dow Corning, as a leader in the organosilicon industry, has proposed material solutions that enable new energy vehicles to travel further.
