Will Solid-state Batteries Be Mainstream In The Future?

- Sep 16, 2019-

As the "heart" of new energy vehicles, power battery directly affects the development of new energy vehicles. Under the current lithium-ion battery system, the combination of high-nickel ternary positive electrode, silicon-carbon negative electrode and electrolyte will reach the performance limit within 3-5 years (the upper limit of energy density is 350Wh/Kg), but it still cannot fully meet the power battery pair. Safety, energy density and cost requirements. Ouyang Minggao, an academician of the Chinese Academy of Sciences and executive vice president of the China Electric Vehicles 100, said that lithium-ion batteries have the potential and prospects of becoming the mainstream technology of power batteries, but the bottleneck is the safety of high-power energy batteries. From the perspective of improving the safety of the battery itself, it is necessary to develop a new type of solid electrolyte battery. Although China's battery industry has temporarily gained an advantage, the international competition is under great pressure, and it is necessary to fully pursue the cutting-edge technology of solid-state batteries. Due to its obvious performance advantages in terms of safety, reliability, energy density, cycle life, etc., solid-state batteries are considered by the industry to be an ideal next-generation battery technology system.

Solid-state batteries have become the development of popular solid-state batteries, that is, lithium secondary batteries with solid materials. The difference between them and traditional lithium-ion batteries is that they replace the electrolyte, electrolyte salts and separators of traditional lithium-ion batteries with solid electrolytes. In general, solid-state batteries have two major advantages. First, it is highly secure. In the case of overcharge or internal short circuit, the traditional lithium ion battery is likely to cause heat generation of the electrolyte, which may cause self-ignition or explosion. The solid battery is non-flammable, non-corrosive, non-volatile, and liquid-free due to its solid electrolyte. Safety is much higher than traditional lithium-ion batteries. The second advantage is the high energy density. Since the solid-state battery uses a solid electrolyte, it does not require a diaphragm and electrolyte, saving nearly 40% of the volume and 25% of the mass. According to the "Long-term Development Plan for the Automotive Industry" and the "Technology Roadmap for Energy-Saving and New Energy Vehicles", the energy density of the power battery system needs to reach 350Wh/Kg (corresponding to the monomer energy density of 500Wh/Kg) in 2025-2030. The cruising range of ordinary electric vehicles. Solid-state batteries are the industry's most important route to meet this requirement. According to public information, the number of patents in the field of solid-state batteries has increased by more than 10 times in the past decade. Many automakers have already started independent research and development, cooperative R&D, or accelerated the development of solid-state battery technology by investing in stocks.

A number of companies announced solid-state battery production time in August 2019, the US new energy company SF Motors division TeraWatt Technology announced the introduction of 4.5Ah solid-state battery design prototype, and the battery's energy density reached a record 432Wh / kg (1122Wh / L ), breaking through the upper limit of the energy density of high nickel ternary. In 2017, Hyundai announced the development of solid-state battery technology. In July 2018, Hyundai announced that it would invest in Ionic Materials, Mass., to further develop solid-state batteries. According to sources, Hyundai will achieve mass production of solid-state batteries in 2025. In July 2018, Volkswagen invested approximately $100 million in QuantumScape, a technology patent with more than 200 patents on solid-state batteries, to establish a solid-state battery production line by 2025. Toyota has a large number of patents in the field of solid-state batteries (252, accounting for 13%, the world's first). At present, Toyota's lithium-ion battery based on sulfide electrolytes and graphite-based anodes promotes the industrialization of solid-state batteries. The energy density of laboratory products reaches 400Wh/Kg. It is expected that electric vehicles with all-solid-state batteries will be launched in 2022, and mass production will be realized in 2025. In addition to self-built cell research and development centers, BMW has developed solid-state battery technology and has also achieved deep cooperation in solid-state batteries with Solid Power. It is expected to achieve mass production of solid-state batteries by 2026. In 2015, Dyson acquired Sakti3, a company specializing in the development of all-solid-state batteries. Sakti3 is a leader in the development of oxide solid electrolytes. In 2018, Dyson said that he is developing an innovative electric vehicle. The production model will be launched in 2020, and the electric power system will adopt the solid-state battery developed by Sakti3.

Will solid-state batteries be the mainstream in the future? China's technological development in the field of solid-state batteries is still in the second echelon, Japan is the first echelon, and mainly based on scientific research institutions such as the Chinese Academy of Sciences and universities. At present, there are three teams in China that are leading the research and development in the field of solid-state batteries. The Cui Guanglei team of the Energy Storage Institute of Qingdao Energy Institute of the Chinese Academy of Sciences has developed a deep sea, high energy density, high-safety solid-state lithium battery power system with an energy density of 300Wh/Kg and applied to the deep sea high pressure environment of 10,000 meters in the Mariana Trench. . The Xu Xiaoxiong team of the Ningbo Institute of Materials Science and Technology of the Chinese Academy of Sciences has developed a 10Ah solid-state single cell with an energy density of 260Wh/Kg, and is currently cooperating with Yanfeng Lithium Industry to promote industrialization. The Li Wei team of the Institute of Physics of the Chinese Academy of Sciences has developed a 10Ah soft-packed battery with an energy density of 310-390Wh/Kg. It is currently working with Weilan New Energy to build a pilot line. For solid-state battery technology, Tesla CEO Musk said, "There is a certain prospect, but it will take time from the maturity of the technology, and it is not enough to change Tesla's strategy at present." Despite the current development of solid-state batteries in China. Very impressive, but there is still a long way to go. The current research on solid-state batteries is still limited to the laboratory stage, and it takes a long time to achieve mass production. Large-scale production needs to consider various factors such as production technology, production equipment, and production environment. Compared with traditional lithium batteries, solid-state batteries have higher requirements for the accuracy of production equipment, and also require a highly dry production environment. In addition, in order to carry out commercial mass production, the solid-state battery requires a certain verification cycle in addition to its own performance, and it also needs to be verified to match the vehicle product of the OEM. According to the planning of most enterprises, the solid maturity of solid-state battery technology may need to wait until around 2025, and the real mass production capacity may need to wait until around 2030. In the short term, solid-state batteries are unlikely to become the mainstream of the industry.

Summary of tram resources The advantages of solid-state batteries are obvious, but everyone should also look at the current shortages. Regardless of the technical route, as long as it can promote the development of the new energy vehicle industry in a healthy, safe and sustainable direction, it is worthy of the industry. Give it a try.