Science and technology
Solid state battery rally starts
At present, solid-state batteries with high energy density and high safety characteristics are receiving attention worldwide. Along with the rapid development of new energy vehicles, the call to improve the cruising range of vehicles is becoming louder and louder. If you want to “run” far away, it is a viable option to select solid-state batteries with higher energy density. In this context, relevant research institutions and enterprises from different countries and regions have entered the "track", opening up a "rally" that will force the layout and accelerate the development of solid-state batteries.
"To achieve the goal of energy density development of power batteries in 2020 and beyond, and achieve the goal of energy density greater than 500Wh/kg, the existing liquid electrolyte battery system may not be able to do anything. As the next generation battery technology route for 500Wh/kg, solid state battery The research and development of the system has become a necessity. The medium and long-term development of the new energy automobile industry requires new technology reserves. The solid-state lithium battery is expected to become the leading technology route for the next generation of vehicle power battery. It is not only an important development direction of the future secondary battery, but also the current Important task." Chen Liquan, a researcher at the Institute of Physics of the Chinese Academy of Sciences, said recently.
Domestic and foreign markets simultaneously
Many large-scale auto companies at home and abroad have begun to develop solid-state batteries in order to win the technical right to develop new energy vehicles in the future. "The major automobile industry powers are not far behind in the development and application of a new generation of high-energy-density power batteries." The analysis of the "China New Energy Vehicle Power Battery Industry Development Report (2018)" released recently pointed out.
In the field of solid-state batteries, Volkswagen has clearly planned. Its large-scale electric vehicle development plan "Roadmap E" is expected to invest 50 billion euros, will carry out long-term strategic cooperation projects for power batteries in China, Europe and North America, and achieve solid-state battery loading applications after 2025, achieving 1,000 kilometers of cruising range . Also active in the layout of solid-state batteries is BMW, which has established a partnership with American battery technology company Solid Power to jointly develop solid-state battery technology for electric vehicles.
In Asia, solid-state batteries are also a hot spot for automotive companies and battery companies. Toyota's "answer" is to jointly develop a square solid-state battery with Panasonic, and plans to develop a new-generation all-solid-state battery with higher density. LGChem, a Korean battery manufacturing R&D company, chose to jointly develop high-nickel NCM, NCA and solid-state batteries with Samsung SDI, and said that mass production of solid-state batteries will be around 2025.
In the face of fierce competition in the international solid-state battery market, China's research team represented by the Institute of Physics of the Chinese Academy of Sciences is also actively promoting the industrialization of solid-state batteries. There are also companies that are also making efforts. Yanfeng Lithium is cooperating with Ningbo Institute of Materials, Chinese Academy of Sciences. Ningde Times, Tianjin Lishen, AVIC Lithium and Weilan New Energy are also developing solid-state batteries.
“It can be seen that both car companies and battery companies are focusing on the development of all-solid-state batteries, which is more like a technical competition for high-energy all-solid-state batteries, which will greatly promote the realization of high-energy all-solid-state lithium batteries. Wu Borong, a professor at the School of Materials Science and Technology at Beijing Institute of Technology, said.
Multiple problems to be solved
According to the reporter, the key to solid-state lithium batteries is solid electrolyte materials. The existing inorganic solid electrolytes and polymer electrolyte materials do not have any high ionic conductivity and mechanical strength, and good processing properties. "At present, high molecular polymer electrolyte materials have low ionic conductivity at room temperature, while inorganic solid electrolytes have problems in preparation. What should we do? We must select their respective advantages and avoid disadvantages." Nan Cewen, academician of the Chinese Academy of Sciences, pointed out that To "best of both worlds", it is necessary to put forward higher requirements for the development of solid electrolyte materials.
In the face of resistance in the development of solid-state batteries, Liu Yanlong, secretary general of the China Chemical and Physical Power Industry Association, also put forward his own views. "The most basic problems are still not solved at the scientific level, that is, the contact interface between solid and solid. High resistance problem. "Excessive resistance not only causes waste of energy, but also causes the battery temperature to rise, which adversely affects its safety performance.
In addition to the technical immaturity, the imperfect market rules are also the "trouble" of solid-state battery growth. Wang Cheng, deputy director of the Beijing Work Department of China Automotive Technology and Research Center Co., Ltd., told reporters that even though the financial subsidy standards for new energy vehicles in the past two years have been linked to the energy density of vehicles and the driving range of vehicles, the new version of the subsidy policy in 2018 has been more refined. And perfect, but for the product energy density indicators require too short iterations, leading to some companies blindly pursue energy density and high subsidies, ignoring the optimization of product comprehensive performance, resulting in the company's technology and products difficult to form accumulation.
"From the perspective of the overall technology chain, the solid-state battery market has the risk of uneven layout and unstable chain, and it is difficult to lay a solid foundation for sustainable development." Wang Cheng pointed out that it is still necessary to further guide enterprises to form at the technical and product levels. A benign development of the health system, "R & D institutions and enterprises should focus on the efficiency of accumulation, in the process of continuous accumulation of quantitative changes, to promote iterative qualitative change."
Solid-state lithium battery into a strategic focus
In the face of the intensive solid-state battery "Arena", China apparently grabbed the tickets for the competition. The "Made in China 2025" issued by the State Council clearly puts forward the strategic layout of the specific energy of the single power battery, high specific energy, high security, long life and low cost solid lithium ion battery, which is the realization of new energy vehicles in China. Drive the key and important support of the technology transformation strategy. Since the 1970s, domestic research institutes, universities, and the advantageous battery materials companies established in recent years with national policies have achieved a series of research results in the research of solid electrolytes and solid-state batteries. At the same time, both the Lithium and Ningde eras have made all-solid-state lithium batteries the focus of research and development for next-generation high-performance power batteries.
"Overall, looking at the path of solid-state battery development, the electrolyte may be from liquid, semi-solid, solid-liquid mixture, solid state and finally to solid state. The negative electrode will go from the graphite negative electrode to the silicon-carbon negative electrode, and finally it may be to the metal lithium negative electrode, but currently There is technical uncertainty.” The Chinese Academy of Sciences academician Ouyang Minggao recently pointed out that “by 2030, it is hoped that breakthroughs will be made in electrolytes, all solid electrolytes will be industrialized, and battery cells are expected to hit 500Wh/kg than energy. In 2030, The cruising range of conventional models should be more than 500km."
At present, the National Natural Science Foundation of China, the Ministry of Science and Technology and the Ministry of Industry and Information Technology have all listed the development of solid-state batteries as a key special project. With the development of more new solid electrolyte materials and the gradual deepening of the research on the reaction mechanism of all-solid lithium batteries, the performance of solid electrolytes is expected. Continuous improvement.
"But it is not enough to rely on the support of the state." Chen Liquan pointed out that "I hope that the lithium battery industry and the Investment Promotion Bureau will attach great importance to it, so that China will win in this fierce international competition, and the power battery industry will change from 'following run' 'Leading' to promote the large-scale promotion and application of new energy vehicles."