Batteries are the driving force behind the electric car industry. Over the past few decades, rechargeable lithium-ion battery technology has been used as major manufacturers have been striving for greater energy density, longer life and better safety. Great progress has been made.
In March 2017, China's Ministry of Industry and Information Technology and the other three national ministries and commissions jointly issued the Action Plan for Promoting the Development of Automotive Power Battery Industry. The Action Plan has planned three development stages for the development of China's automotive power battery: First, continue to improve the performance quality and safety of existing products, further reduce costs, guarantee high-quality power battery supply by 2018; secondly, vigorously promote the development and industrialization of new lithium-ion power batteries, and achieve large-scale application in 2020; Focus on strengthening the new system power battery basic research, achieving technological change and development testing in 2025. All these efforts are to reduce costs, improve the performance of Chinese-made power batteries, and make China's electric vehicle industry have greater competition in the global market. Advantage.
Challenges and opportunities
But the price of power lithium batteries is still very high, accounting for a full third of the total cost of electric vehicles. Owners and manufacturers will not be willing to invest too much money in replacing batteries. The key to the Chinese market is Make sure consumers don't hesitate to buy electric cars because of expensive battery replacement costs. When the general public can afford the purchase and maintenance of electric vehicles, the overall sales growth can reach the goal.
Therefore, high efficiency and strong performance are essential for power batteries, especially the pure battery life and battery life of the vehicle. If these difficulties are overcome, China's lithium battery industry will be able to remain competitive in the global market. Finding the right solution for battery performance has become one of the hottest topics in the Chinese electric vehicle industry. Currently, discussions in this field focus on battery raw materials, positive and negative electrodes, electrolytes, diaphragms, and battery PACK systems and battery management systems. BMS) and other technologies. However, the stability of a single battery casing, as well as its structural weaknesses, are often overlooked, making it one of the factors affecting battery performance and service life.
Find the weak link of the battery
It should be noted that there are some potential weak points in the battery. The first is the seam layer between the battery 'can body' and the battery cover that houses the electrolyte and battery components. The tank is often made of a single deep-drawn aluminum plate. The airtight performance test of the battery is carried out in a vacuum chamber. If there is electrolyte in the battery, then a helium gas with a ratio of 3-5% will be added for subsequent testing. In the vacuum chamber, as small as 10-6 or 10- The leakage of 7 mbar·l/s can be detected by the helium test.
Other weak points include electrodes, filled holes and safety air holes. In electric vehicle applications, polymer materials are often used for sealing, but the organic components of the polymer are subject to aging and degradation over time. In addition to the problem of electrolyte leakage (electrolyte can be volatilized through the polymer seal), once water vapor enters the battery, it may react with the lithium salt to form an acid, such as hydrofluoric acid, which adversely affects the chemical balance and reduces battery performance. At the same time, it is also extremely corrosive to the battery as a whole.
Due to the vibration and heat during the driving process, coupled with environmental problems such as bad weather and dust on the street, the application of batteries in electric vehicles will face many challenges. The battery must be pointed out in the “Promoting Action Plan for the Development of Automotive Power Battery Industry”. Ensure safe operation in the temperature range of -30 ° C to 55 ° C. 1. In the 2016 Energy Saving and New Energy Vehicle Technology Roadmap published by the China Automotive Engineering Society, the standard of the number of battery charging cycles should be greater than ten years. It is equal to 4000 times. 2. Therefore, it is an extremely important task for electric vehicle manufacturers to ensure that the battery does not leak and is completely isolated from the outside world to optimize performance.
SCHOTT launches glass-aluminum seal (GTAS)
Usually the battery cover is fixed to the tank by laser welding technology, which can form a gas-tight connection. Then the polymer seal becomes the only potential leak point. If you use the advanced new glass-aluminum seal (GTAS) The material is replaced by a polymer as a sealing material, and the airtightness problem can be improved. The glass and aluminum materials used in the sealing field are an innovative design. By continuously adjusting the glass composition of the aluminum material, two materials are made. The coefficients of thermal expansion match each other, eventually achieving an impenetrable, long-lasting seal.
This process is called a compression seal. When two materials are heated, the metal expands faster than the glass. Then once the cooling process begins, the metal begins to shrink at a higher speed than the glass, and a compressive force is applied to the glass from the outside. The electrodes of the battery are sealed inside the glass. The pressure generated by this process ensures a strong mechanical bond between the glass and the aluminum alloy. This applies to applications such as electric vehicles that require extremely high stability between the operating components and the battery. Significant.
Glass-Aluminum Seal - Progress in Leap
Glass-Aluminum Seal (GTAS) is the first in the electronic packaging division of SCHOTT Group of Germany. Its glass-to-metal sealing technology (GTMS) has been used on a large scale for the sealing of electronic components such as automotive sensors, capacitors and airbag initiators. After a lot of research and development work on GTMS, the technicians developed a glass-aluminum sealed GTAS technology for lithium battery aluminum casing.
Sealing the polymer with high-performance glass-aluminum sealing technology can effectively prevent the aging and corrosion of the polymer over time. This in turn protects the stability of the chemical inside the battery, thus ensuring longer Lifetime and higher battery performance. This year, China's domestic electric vehicle sales are estimated to exceed 1 million units. Chinese battery manufacturers can use this technology to better serve the growing electric vehicle market.
SCHOTT is a leading international technology group in the field of specialty glass and glass ceramics. We have decades of experience in the automotive industry, and our products provide long-lasting and reliable protection for precision automotive electronics and lithium batteries.
