It is still doubtful that semi-solid batteries can be mass-produced and commercialized on a large scale.

As the "heart" of the electric vehicle, the performance of the power battery directly affects the driving condition of the vehicle. It is no exaggeration to say that electric vehicles are "Cheng Ye power battery, failure also power battery". Therefore, both power battery enterprises and new energy vehicle enterprises are trying to break through the bottleneck of power battery technology.

At present, ternary lithium battery and lithium iron phosphate battery are still the two mainstream technology routes of new energy vehicle power battery, but restricted by the safety and stability of the former and the energy density of the latter, solid-state battery has been gradually placed high hopes by the industry in recent years, and is considered to be the most innovative technology route, which can greatly improve energy density, durability and safety.

More than 20 companies compete for solid-state batteries

Under the general trend of the development of the industry, according to incomplete statistics, there are more than 20 automobile and power battery enterprises around the world that are committed to the research and application of solid-state battery technology, and many of them have announced that they will mass produce solid-state batteries. And formulated the corresponding development route plan.

Internationally, Volkswagen, Toyota, Honda, BMW, Panasonic and other automotive companies and battery enterprises have a layout in the field of solid-state batteries. Among them, BMW began to hold hands with Soild Power to develop solid-state batteries in 2017; Toyota, as one of the early car companies to develop solid-state batteries, focusing on sulphide solid-state electrolyte technology, is expected to launch models with solid-state batteries in 2022; in early 2020, Toyota announced a joint venture with Panasonic to produce solid-state batteries. In the same year, Daimler announced a partnership with Canada's Quebec Hydro to develop solid-state battery technology, which will be used in Daimler's electric vehicles once it reaches mass production. On March 15 this year, Volkswagen said at its first Battery Day that the goal of future power batteries is solid-state batteries.

Domestically, Qingtao Energy, Ningde era, Ganfeng Lithium Industry, Huineng, Beijing Weilan, Carney New Energy and other power battery enterprises are in the forefront of solid-state battery research and development. It is understood that Qingtao Energy has developed all-solid-state batteries with a monomer energy density of 430W / kg and more than 300Wh/g in the stage of mass production; Ningde era has studied both polymer solid-state lithium-metal batteries and sulfide-based solid-state batteries; Ganfeng lithium industry has an annual production capacity of 100 million watts per hour of first-generation solid-state lithium battery R & D pilot production line has been completed and trial production; Weilan New Energy laid the foundation for the solid-state battery project in Jiangsu in 2019, and plans to build an annual 0.1GWh solid-state battery production line. Huineng Technology said that trial production of all-solid-state batteries will begin in 2023 and all-solid-state batteries will be mass produced in 2024.

In addition, traditional car companies such as BAIC and BYD, as well as new car manufacturers such as Xilai, Skyline and Aichi, have a layout in the field of solid-state batteries. In particular, on January 9 this year, the first 150kWh solid-state battery was released on NioDay. The news that the mileage of the Xilai eT7 car with the battery will exceed 1000 km has rekindled the attention of the industry to the solid-state battery.

Semi-solid is the direction, and large-scale commercialization is still in doubt.

Under the competitive layout of many enterprises, the commercialization process of solid-state battery has naturally become the focus of the industry. At the Blue Book Forum held a few days ago, the topic of "when solid-state batteries can be commercialized" triggered a heated discussion.

Xu Xiaoming, general manager and founder of Anchi Technology, said that it will be difficult to see pure solid-state batteries before 2030, and even if they see a real solid state, they will be mainly used in consumer electronics for at least the first three to five years, so that they are safe, controllable and affordable.

It is understood that in terms of battery structure, solid-state batteries using solid electrolytes have the advantages of non-flammability, non-corrosion, non-volatilization and non-leakage, which can greatly ensure the safety of the battery. At the same time, the solid-state battery with metal lithium as negative electrode can match the high-voltage cathode material and further increase the energy density. But it is precisely because of this solid state that solid-state batteries also have congenital defects. For example, the lithium ion transfer efficiency of the solid electrolyte will directly affect the ionic conductivity of the solid electrolyte, and the interface impedance between the electrode and the electrolyte will increase.

Considering the practical difficulties faced by the mass production of solid-state batteries and the urgent demand for high-safety and high-energy-density power batteries for new energy vehicles, as a compromise, the industry regards mixed solid-liquid electrolyte lithium batteries as the transition scheme for the development of solid-state batteries. "semi-solid batteries are feasible to solve safety problems, and then increase the energy density." Xu Xiaoming said.

Liao Zhenbo, deputy general manager of BAIC, said that when 5% of the hybrid battery is liquid, it should be relatively safe, and the energy density also meets the requirements of automobile companies. At the same time, he stressed that under the condition that the energy density is not reduced, it is necessary to enhance safety, do not take other routes, and build solid-mixed batteries in a down-to-earth manner. "I strongly appeal to these battery companies, do not hesitate, quickly industrialization, to provide the whole vehicle enterprises with safe and reliable solid-mixed batteries."

In the final analysis, the reason why Liao Zhenbo made such a strong appeal is the safety of power batteries. He said that at present, the problems that automobile companies urgently need to solve have changed from the original pursuit of energy density and cost elements to the current pursuit of ranking to the three elements of safety, cost and performance. He also specifically mentioned that the cost is not only the cost of battery procurement, but also consider the situation of after-sale and recall.

"every year in the summer, new energy vehicles will have fire accidents, and the proportion of car recalls will be increasing. According to China's recall system, 4/10000 of design safety quality accidents will be recalled, so the loss to the whole vehicle enterprise is very great, so now we separate the cost problem, one is the procurement cost, and the other is the after-sales service, including the recall service just mentioned, so when the safety cannot be guaranteed, the cost is very high, so the most important thing for vehicle enterprises is to pay attention to safety. "

Wang Wei, chairman of Funeng Technology, also said that semi-solid state is definitely the direction of future development. "No one wants to have hidden dangers in the process of producing batteries. If you use semi-solid batteries, your factory will no longer have a fire problem." the ultimate goal is to thoroughly solve this problem from the material itself.

However, in the view of Yang Hongxin, chairman and CEO of Honeycomb Energy Technology Co., Ltd., although semi-solid battery technology can solve the problem of mass production, it does not mean that it can be commercialized on a large scale. "large-scale commercialization requires engineered capabilities to support it, and users are willing to pay for it, and now we can't find the core selling point of semi-solid batteries." Yang Hongxin points out that the cost of semi-solid will increase and the production line will have to be adjusted, but the impact of the first generation of products on the production line is not great, so technical problems can be solved and mass production can be achieved, but there is still considerable uncertainty about large-scale commercialization.

New Breakthrough in Sodium Ion forming Power Battery Technology

On the whole, under the influence of many restrictive factors, semi-solid battery as a compromise scheme can take into account the performance advantages of liquid lithium battery and all-solid-state battery, maximize compatibility with existing processes, equipment and materials, and have the possibility of mass production. However, there is still some uncertainty in large-scale commercial applications. So, before the real commercial application of semi-solid battery, what new breakthroughs will be made in the technical route of power battery?

"I think the sodium ion battery is a very good breakthrough. A very important point for the sodium ion battery in the future is that the sodium resource is relatively abundant and the cost is relatively low. In addition, the sodium ion battery is relatively cheap, and the disadvantage is that the energy density is relatively low." Wang Xing, chairman of Funeng Technology, said.

On May 21 this year, the director of Ningde Times, Chang Zeng Yuqun, revealed at the shareholders' meeting that the sodium ion battery would be released around July this year. This move is regarded by the industry as an important measure for the scarcity of lithium resources in the Ningde era and the resulting high price of lithium raw materials.

Yang Hongxin, chairman and CEO of Honeycomb Energy Technology Co., Ltd., said, "Lithium resources in China are very scarce. Strategically, there should be a way to solve the problem in terms of raw materials. Sodium ion batteries are particularly good." However, in passenger cars, the large-scale use of sodium ion batteries, at least in the past few years, may still be very challenging, and may replace some lead acid and iron lithium. "

However, the sodium ion battery is still in the early stages of industrialization. Xu Xiaoming, general manager and founder of Anchi Technology, pointed out that the sodium ion battery will not mature until at least five years later, because it reconstructs the entire chemical system of the existing battery.

In addition, Wang Jie, chairman of Funeng Technology, firmly said that ternary batteries will also become the mainstream of passenger cars, as for the current debate on ternary lithium batteries and lithium iron phosphate batteries. "We hope to use three-and-a-half volume and half weight for 20 minutes to release 30 kilowatt-hours of electricity and 50 kilowatt-hours of electricity to meet the demand. This is the whole direction of the future, and the development of human society still needs technological progress to promote the development of human society." He also said that the safety of NCM811 is completely controllable, but it has not yet reached this level, from raw materials to battery manufacturing to vehicle control to early warning, but it can be done in the future.