Industry explores lithium battery electrolyte upgrade

2021-05-02

Although China Drying Reuters has not yet finally passed the difficulties of low grade, poor quality stability, and high production costs, the electrolyte of one of the four pillars of lithium-ion batteries, especially its key material, lithium hexafluorophosphate (LiPF6), appeared. A tendency to catch up. At the China Lithium Battery Electrolyte Symposium recently held in Suzhou, experts Chen Yan made a breakthrough in product performance, safety, and production cost through collaborative innovations in production, research and development, and developed and manufactured high-grade lithium hexafluorophosphate materials to replace imports. The demand for large-capacity, small-volume battery markets for mobile phones and tablet computers will enable China's lithium-ion battery materials industry to embark on a healthy development.

Lithium-ion battery mainstream electrolyte lithium salt is still lithium hexafluorophosphate. Compared with other electrolyte lithium salts, lithium hexafluorophosphate has good ionic conductivity and electrochemical stability, and the recycling of waste batteries is simple and the environmental protection performance is good. Therefore, due to the dual influence of policy encouragement and market-driven, in recent years, Guotai Huarong, Xinzhou State, Guangzhou Tianci and other enterprises have newly built and expanded production projects to increase electrolyte production capacity. Ube Japan and Dow Chemical established a joint venture company for electrolytes in China, and Mitsubishi Chemical also established a wholly-owned subsidiary to establish a new electrolyte project. As a result of breakthroughs in the industrial synthesis technology of lithium hexafluorophosphate, domestic polyfluorinated chemicals, Guotai Huarong and other companies have gradually begun to develop from pilot to volume industrialization.

After a large number of projects were launched, the current import ratio of lithium hexafluorophosphate in China has dropped to 62%. Compared with more than 80% of imports over the years, the localization level has been greatly improved. However, most domestic lithium hexafluorophosphates are constrained by the high free-acid bottleneck. They face challenges in terms of quality stability and production costs. The products cannot be used as high-end lithium battery materials such as mobile phones and tablet computers. In the industrialization of lithium hexafluorophosphate, China still lags behind Japan and other developed countries.

Zhao Yongfeng, deputy general manager of the company, said that in order to participate in international competition, it must build its own core competitiveness. This competitiveness relies heavily on technological innovation and market development, rather than pure capital investment.

Delegates generally agreed that before the large-scale opening of the electric vehicle and energy storage market, domestic enterprises should seize opportunities for rapid development of lithium battery applications such as smartphones, tablet computers, and mobile power, and pay attention to electric bicycles and low-speed electric vehicles. Lithium battery alternative application potential.

At present, there are major differences in the quality of domestic lithium salt and Japan and South Korea's lithium salt, such as HF content control and cycling performance after core formation. Experts suggested that the production process of lithium hexafluorophosphate is more complicated and the most difficult to grasp in mass production is the uniformity of product purity. There are many factors that affect product quality, including raw material quality, equipment sophistication, and process control, which are the direction of domestic companies' technological breakthroughs.

Some experts believe that the electrolyte is a complex system formulated with organic solvents, lithium salts, and additives. How to work out the best formula for a new type of electrolyte lithium salt needs to be dared to try. Although the new electrolyte lithium salt will not replace lithium hexafluorophosphate on a large scale in the near future, the new trend in the world is to develop a variety of lithium salt mixtures for use according to the performance requirements of electrolytes. Conditional companies can focus on R&D in this area.

Wang Xinlong, associate professor of the School of Chemical Engineering of Sichuan University, said that they have successfully developed a new process for lithium hexafluorophosphate and hope to find partners to conduct pilot tests. This partner not only has funds, but more importantly, it has downstream product and production management experience and has made breakthroughs through collaborative innovation.

Xia Lei, general manager of Asian Chemicals Consulting, proposed that companies should formulate expansion plans based on market demand, and do not blindly follow suit. Over the past few years, the gross profit margin of the electrolyte industry has gradually decreased, and the low-end electrolyte may be surplus in the next few years. Therefore, we must vigorously develop high-end electrolyte and lithium hexafluorophosphate materials, and pay attention to the development trend of new lithium salts such as lithium bis(fluoro)sulfonyl imide (LiFSI) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI). In addition, we must establish an “allied force” in the industrial chain to allow electrolyte manufacturers to work closely with downstream lithium battery manufacturers and downstream battery applications to develop electrolyte products and materials that meet customer needs and strengthen after-sales services. This is also a major trend in the development of the electrolyte industry.