Looking at the world, solid-state batteries are not a new product. In traditional liquid lithium batteries, the battery completes the charge and discharge process during the movement of lithium ions from positive to negative and then to positive. Solid-state batteries work in the same way, except that the electrolyte is solid.
Back in 2017, Fisker, an American electric vehicle company based in Anaheim, California, issued a patent for a solid-state battery that can be charged for one minute and have a range of 800 kilometers. Founder Henrik Fisker says the company's solid-state batteries will be in mass production by 2023 at a third of the price of traditional lithium batteries. However, in 2021, Henrik Fisker said that he had completely abandoned the solid-state battery project.
At present, the only company in the world that has commercialized a powered solid-state battery is the Bollore Group of France. In October 2011, the Bollore Group began to carry solid-state batteries manufactured by BatScap on its self-developed electric vehicle "Bluecar" and electric bus "Bluebus", a total of 2,900 electric vehicles. However, the capacity of this solid-state battery pack is only 30KWh, and the energy density is only 110Wh/kg.
In the view of the industry, the industrialization of solid state lithium batteries, from the technical point of view, there are still no small challenges.
The first is the low ionic conductivity of solid electrolytes, especially at low temperatures. Secondly, the interface resistance at the solid interface of electrode and electrolyte is large. In addition, new materials such as pre-lithiated silicon carbon negative electrode or future lithium metal negative electrode, high nickel positive electrode, and solid electrolyte used in solid state batteries completely subvert the current liquid lithium battery system, and the production cost is much higher than the current corresponding materials, and the road to cost reduction is extremely arduous and long.
It is understood that there are currently three mainstream systems for solid electrolyte materials: polymers, such as lithium hexafluorophosphate doping into PEO; Oxides, such as lithium steel zirconium oxide (LLZO), NASICON, etc.; And sulfides, such as LPSX(X=Cl,Br,I).
Among the three material routes, the advantage of the polymer system is that the high-temperature ion conductivity is high and it is easy to process. However, its ionic conductivity at room temperature is very low, which restricts its development. For example, the French Bollore brand solid-state battery uses a polymer system, in order to allow electric vehicles to work normally at room temperature, Bollore Group specially equipped each car with a heater, and the battery system was heated to 60 ° C to 80 ° C before starting.
The oxide system has the advantage of good overall performance, but the interface resistance between the electrodes is higher than that of the polymer system. Among them, thin-film products have strict requirements on process technology, and it is difficult to cost and scale production. Non-film products are currently the most reliable electric vehicle battery solutions.
The advantage of sulphide systems is that their ionic conductivity is comparable to that of liquid electrolytes, which is the technological route chosen by Japanese and South Korean companies Toyota, Honda, Samsung and Chinese battery giant CatL Time. However, the development progress of sulfide systems is at the most preliminary stage, production environmental restrictions and safety issues are the biggest obstacles, and the risk of commercial mass production is also the highest.
Despite the difficulties, however, in the pursuit of future lithium battery energy density and safety on the road, solid-state batteries are still placed high hopes. It is understood that at present, there are more than 50 manufacturing companies, start-up companies and university research institutes around the world are committed to the advancement of solid-state battery technology.
In Europe and the United States, BMW Group invested $130 million in Solid Power, a solid-state battery startup based in Colorado, USA, in 2022, and plans to launch a prototype vehicle equipped with solid-state batteries by 2025 and achieve mass production by 2030.
Mercedes-benz reached a strategic agreement with Massachusetts-based solid-state battery startup Factorial Energy this year to invest about $1 billion to support solid-state battery research and development, and start testing prototypes in 2022 and achieve small-batch production within five years.
The Volkswagen Group invested $100 million in Silicon Valley-based solid-state battery startup QuantumScape in 2018 and an additional $200 million in 2020. This year, Volkswagen announced that it would use solid-state batteries in its electric vehicles by 2025.
Japan and South Korea, Toyota in 2008 and solid state lithium battery company Ilika launched cooperation, its plan to launch in 2025 with solid-state battery hybrid vehicles. Mitsubishi, Nissan, Panasonic and other companies have also accelerated the layout of solid-state batteries. It is understood that at present, Toyota has 1331 global patents related to solid-state batteries, ranking first in the world, Panasonic 272 ranked second.
Domestically, Nio released a solid-state battery with a lithium energy density of 150Wh/kg on Nio Day on January 9 last year, and it plans to achieve mass production in the fourth quarter of 2022. Ningde Times previously said that the energy of the company's first generation of solid-state lithium batteries is roughly the same as the current lithium-ion battery, which is expected to be launched in 2025, and the second generation of solid-state batteries is expected to be launched after 2030. In addition, domestic companies such as Funeng Technology, Beehive Energy and Ganfeng Lithium have also announced the layout of solid-state batteries.
