Recently, the "Second International Exchange Conference on New Energy Vehicles and Power Lithium Batteries (CIBF2021 Shenzhen)" was held in Shenzhen. At the special forum titled "Soft Bag Battery Core Materials and Advanced Technology Breakthrough" by Fengfan Co., Ltd., Mei Ao, a senior engineer at the Automotive Engineering Research Institute of Guangzhou Automobile Group Co., Ltd., delivered a speech with the theme of "New Materials Drive Performance Improvement of Power Lithium Batteries".

It is reported that GAC Research Institute is a research and development institution directly under GAC Group. In addition to Guangzhou General Institute, there are branches in Shanghai and overseas. The research institute has 4300 research and development personnel, mainly engaged in the research and development of complete vehicles and key components. Guangqi Research Institute is a nationally recognized technology center. In the biennial evaluation, it ranked sixth among 1563 technology centers in various industries nationwide in 2019 (automotive). In terms of electrification, the research institute has conducted a lot of development on key components, including batteries, electromechanical coupling systems, etc.

Mei Ao stated that materials have a significant impact on the performance of battery cells, and from the perspective of the entire vehicle, it is ultimately to meet the needs of consumers.

Firstly, to increase the vehicle's range, it is necessary to increase the battery energy density, and the energy density of ternary batteries must be made of high nickel materials. By calculating and analyzing the energy density of batteries, it can be concluded that high nickel ternary materials can only achieve the advantage of high energy density when combined with more advanced silicon carbon negative electrodes; If it is only paired with graphite, the density is equivalent to that of medium nickel ternary after increasing the voltage.

In terms of cost reduction, the proportion of nickel can be increased by reducing the content of cobalt used. We have conducted a lot of analysis and calculations, and in the future, there will be great breakthroughs in the smelting technology of laterite nickel ore, which will be a good way to reduce costs for high nickel ternary. It is important to use cheap laterite nickel ore, which also contains cobalt and can be applied, "said Mei Ao.

The use of negative electrodes for silicon is also a direction to pay attention to. Mei Ao stated that there are now technological routes for silicon oxide and silicon carbon. In principle, silicon oxide is nano sized. In terms of its essential production and manufacturing process, the economy, cost-effectiveness, and practicality of silicon oxide have certain advantages in reducing costs. It is estimated that when it is truly mass-produced, silicon oxide will reach the cost of high-end graphite, which high-performance cars can accept.

Mei Ao also mentioned that the use of silicon is important to pay attention to the obstacles of expansion application, including the expansion of silicon materials, SEI film elements, and the damage to electrode structure caused by expansion. To solve these problems, relying solely on materials is not enough, and it is necessary to limit and buffer from aspects such as electrodes, cells, and modules. Adhesives are also an important part, and suitable and specialized adhesives can greatly help with the use of silicon.

In terms of safety, when discussing the safety research and development work of electrolytes, Mei Ao stated that it is important to use high mountain resistors and flame-retardant specially designed electrolytes. Through experiments, it has been found that flame-retardant electrolytes have a relatively significant effect on improving thermal runaway. Testing the yield of C80 with different electrolytes and electrodes clearly shows that using flame-retardant electrolytes can significantly improve the temperature and heat release of thermal runaway.

Mei Ao stated that GAC is also developing battery cells internally, including materials and applications. Planning began in 2015, and relevant silicon announcements were also made last year. Some loading experiments were also conducted. In 2019, the target experiment of Heihe Low Temperature was already installed, and a high-end model with a range of 1000 kilometers will be launched.