On February 8, 65438, QuantumScape, a startup invested by Volkswagen and Bill Gates, released the latest performance data of solid-state batteries after ten years of research. It is said that this solid-state battery may also be the first commercially feasible solid-state battery. When the stock market heard the news, QuantumScape's share price rose sharply.
This solid-state battery can increase the cruising range of electric vehicles by 80%, and it can fully charge 80% of electricity in 15 minutes, and will be put into production in 2024. The key to its breakthrough is to replace liquid electrolyte with flexible ceramic electrolyte. It is reported that even at the extremely low temperature of MINUS 30 degrees Celsius, the battery performance will not be affected.
That sounds exciting. However, the biggest question is that many details of the battery have not been announced. As stated in the research report of CICC, only a single laminate is displayed now, not the battery, so it is impossible to determine the power of the battery and calculate the supporting conditions of its charging facilities. Conversely, is QuantumScape just "putting a PPT satellite"?
What is QS hiding?
QuantumScape talked about many exciting technologies in this briefing. For example, compared with the traditional lithium-ion battery, this solid-state battery can still maintain more than 80% capacity after 800 times of charging, and the technology has made remarkable progress.
In addition, this battery is flame retardant, and its volume energy density exceeds 1000Wh/L, which is almost twice the density of top commercial lithium batteries. It is also the current Tesla model? Three times the battery used.
That sounds great. Stan Lian, co-founder of the company, inventor of lithium-ion battery and one of the winners of the 20 19 Nobel Prize in Chemistry? Whittingham said, "The most difficult part of manufacturing solid-state batteries is to meet the requirements of high energy density, fast charging, long cycle life and wide temperature range at the same time. The data shows that QuantumScape's solid-state battery fully meets all these requirements, which has never been reported before. If the company can put this technology into mass production, it may change the whole industry. "
However, QuantumScape also has many hidden things.
For example, according to the research report of CICC, firstly, QuantumScape did not give the specific technical route and detailed battery parameters; Secondly, the battery sample shown is only a single laminate, not a real battery cell. In other words, it is only laboratory data at present.
In terms of materials, according to the layout and publicity of QuantumScape patent, the route of QuantumScape solid-state battery should be oxide garnet-like composite oxide solid-state battery (composite? Garnet? Solid? Battery), the mainstream electrolyte system is Li3La3Zr2O 12(LLZO), that is, lithium lanthanum zirconate.
Moreover, Google's CICC? A large number of patent systems related to QuantumScape found in patents are also lithium lanthanum zirconate oxides. This is also the most likely mass-produced material in the oxide route of solid-state batteries at present, and it is also a branch of the oxide electrolyte system that is most stable to lithium metal newly discovered after 2007. In fact, with the development of ceramic cleaning in China, two small production lines have been put into mass production.
Therefore, it is not surprising that the popular solid-state batteries take the flexible ceramic electrolyte route under the oxide system. However, the lithium lanthanum zirconate system has both advantages and disadvantages.
The characteristics of lithium lanthanum zirconate (LLZO) system are as follows: firstly, the electrolyte with the best adaptability to lithium metal in all electrolyte systems of solid-state batteries is relatively more likely to directly skip the silicon anode and realize the application of lithium metal anode. Secondly, the electrochemical window of LLZO is very wide, and it can withstand voltages above 5V.
However, LLZO system has many disadvantages. For example, the conductivity of this garnet composite system is only 10-4, which is two orders of magnitude lower than that of liquid electrolyte. Secondly, the interface performance between LLZO and cathode is poor. This is because, on the one hand, the garnet structure makes the contact surface with lithium metal uneven, on the other hand, the contact with the positive electrode is relatively poor.
Therefore, the solutions currently explored in China include composite cathode, optimization of interface treatment process, introduction of interface layer and electrolyte recombination. For example, the development of pottery in Qing Dynasty took the road of composite anode.
In addition, the preparation process is complicated and the sources of manufacturing equipment are different. In other words, the existing lithium battery production system is not universal and must be rebuilt. Besides the battery itself, the construction of supporting facilities is also very important.
20 17, Fisco once said that "you can run 800 kilometers in one minute". However, according to the calculation of Lu Yixing, the commune data group, to achieve this effect, the diameter of the aluminum conductor of the charging pile should reach 60CM, which is even thicker than the washbasin. Is it possible? In terms of current technology, "this is simply an effect that only lightning can achieve!"
According to this model (the current universal voltage is 350V), the reporter calculated that the solid-state battery should be filled 80% in 15 minutes, and the diameter of the aluminum conductor of the charging pile should be above 15CM. Even if it is replaced by a copper conductor with twice the conductivity, the diameter should be above 7.5CM, which is still difficult to achieve at present (please add WeChat to discuss karma-shan for the calculation method.
Recently, the ideal Li Xiang said, "Only when the technology of the second generation electric vehicle is mature, Li will do pure electric." A sign of the second generation technology is the fast charging of 400kW under the 800V voltage platform. But in reality, it may be difficult to achieve 400kW charging power in 5~ 10 years.
We know that the landing of the 350kW super charging pile that Tesla hopes is still uncertain. Therefore, considering all kinds of situations, solid-state batteries can really achieve mass production and commercialization, and the time point given by the industry is after 2030.
Therefore, there are also doubts in the industry. QuantumScape said that solid-state batteries are planned to be mass-produced in 2024~2025. What is the possibility? On the whole, the battery monomer with lithium lanthanum zirconate as electrolyte has certain practicability in theoretical performance, but it is still a long way from mass production.
Therefore, this solid-state battery seems to be the response of QuantumScape and Volkswagen to the investment pressure, and put a PPT "big satellite" to give investors confidence. It can be understood from the aspect of investment that after ten years, certain achievements have been made. Besides, the stock market is betting on the future.
However, the reporter still consulted relevant people in the industry, and they said that lithium lanthanum zirconate containing rare earth components "this route should be difficult." There are two elements with too little content. "The vulcanization route is feasible. This is also what Toyota considered at the beginning of developing solid-state batteries. So how far the oxide route can go, we can't draw a conclusion yet.
Path of solid-state battery
Let's talk about solid-state batteries. The principle is very simple, that is, solid or semi-solid electrolyte is used to replace the liquid electrolyte used in existing lithium batteries. Technically, the thickness of solid electrolyte can be very thin, that is, tens of microns, which reduces the volume and weight. Solid-state battery with high energy density and high safety is the ultimate goal of battery technology.
The beginning of solid-state batteries can be traced back to 1972 at the earliest. In those days, Scrosati? A solid lithium ion primary battery with LiI as electrolyte is reported for the first time. 1 1 year later, 1983, Toshiba of Japan developed a practical Li/TiS2 thin-film all-solid-state lithium battery. Since then, the research on solid-state batteries has been going on.
It is worth noting that at present, the conductivity of most solid electrolytes is less than 10 times, which is an order of magnitude. Therefore, the fast charging performance is very problematic and I am afraid of large current. In addition, if the solid-state battery wants to surpass the mass and energy density of the current battery system, it only needs to realize the application of lithium metal cathode, which is quite difficult.
Therefore, the core technological breakthroughs of solid-state batteries mainly lie in the solid electrolyte material technology with high ionic conductivity and the manufacturing technology of solid-solid interface with low impedance. Although solid-state batteries have the advantages of good safety performance, high energy density and long cycle life, it is still early to realize mass production application in automobile industry.
For example, at present, the battery performance of solid-state batteries is only slightly better than that of liquid batteries (monomer energy density is 400Wh/kg), and the cycle life is not higher than 500 times. This time QuantumScape announced that it can charge 800 times. Although this data is very good, it should still be only experimental data.
Say that finish abroad, talk about China. Academician Chen Liquan is the first person in China to pay attention to solid-state batteries. According to his account, in 1987, the Ministry of Science and Technology of China listed the solid-state lithium battery as the first major project of the "863" plan. However, according to the technical level at that time, this task is obviously a "mission? Impossible.
Until 20 12, China's Ministry of science and technology once again included solid-state lithium batteries in the "863" plan of the Twelfth Five-Year Plan. In 20 18, the Ministry of Science and Technology of China listed the solid-state lithium battery for power and energy storage in the national key research and development plan.
20 19- 12, the Ministry of industry and information technology issued the development plan of new energy automobile industry (202 1-2035) (draft for comments). In the "implementation of battery technology breakthrough action", accelerating the research and development and industrialization of solid-state power battery technology is listed as "key technology research project of new energy vehicles". From the course of these years, we can also see how difficult the technology of solid-state batteries is.
According to the Report on Special Investigation and Development Trend Analysis of All-solid-state Battery Market in China in 20 19-2025 released by Zhiyan Consulting Co., Ltd., from a global perspective, at present, Japanese and Korean patent technologies in the field of solid-state battery research and development are more advanced.
From 1990 to 20 18, the number of patents published in the field of solid-state batteries was 1926, among which the number of patents in the field of all-solid-state batteries reached 87 1, accounting for about 45%. Geographically, Japan has 9 16 patents for solid-state batteries, accounting for nearly half, leading by a wide margin. China's patent is 362? Pieces. In terms of all-solid-state batteries, Japan has 657 patents, accounting for 75%, and its leading edge is more obvious. In this regard, China and South Korea have patents respectively? 128? Piece, 37? Pieces. The United States has only 29 patents in the field of all-solid-state batteries.
Therefore, although enterprises in China are loud, there are not many real patents. It is generally difficult for China enterprises to continuously invest in the research of solid-state batteries, and some prefer to "brag" first. Many of the results of the explosion are told to investors, and few can really land. This is what we need to treat rationally.
Japanese sulfide route
Let me talk about another mainstream route. Domestic pottery and QuantumScape take the oxide route, while Japan? Japanese and Koreans take the sulfide route.
Now we are talking about solid-state batteries, and their solid electrolytes can be roughly divided into three categories: inorganic electrolytes, solid polymer electrolytes and composite electrolytes. At present, there are two mainstream in the industry, sulfide and oxide, in addition to solid polymers and films.
Although oxides have the advantages of high safety and easy production, the improvement of ionic conductivity at room temperature is still a century-long problem. Although the polymer route is the first to achieve small-scale mass production and mature technology, it is similar to "an athlete who needs to take stimulants for a long time" and "debut is the peak", which has no follow-up potential and belongs to the marginalized non-mainstream.
Sulfide route is the most technically difficult of the three routes, but it has great potential and is sought after by Japanese and Korean enterprises. However, only Japanese and Korean companies can be patient and study hard.
Toyota is a staunch supporter of sulfide technology. Through years of silent research, Toyota has achieved certain results. Toyota originally planned to launch a pure electric vehicle equipped with sulfide solid-state batteries at the 2020 Tokyo Olympic Games, and planned to achieve mass production in 2022. However, due to the epidemic, Toyota postponed its debut plan.
However, Guisi, executive vice president of Toyota Motor Powertrain Company and general manager of battery industry? Keita once said that Toyota plans to mass-produce solid-state batteries by 2025, with energy density more than twice that of lithium batteries and higher charging efficiency. It only takes 15 minutes to fully charge from zero.
Toyota's technical foundation in solid electrolyte materials comes from the sulfide solid electrolyte invented by Professor Kenno 20 1 1 of tokyo institute of technology. Its room temperature ionic conductivity is >: 10-2S/cm (exceeding the traditional organic electrolyte).
After more than ten years' research, Toyota has not only obtained patents for solid electrolyte materials and solid battery manufacturing technology, but also developed a set of technical routes and recycling procedures for cathode materials and sulfide solid electrolyte materials. This is why Volkswagen is also eager to invest heavily in solid-state batteries. The opponent is too strong.
In addition, Samsung and BMW are also developing technologies for sulfide solid-state batteries. At the beginning of March this year, Samsung Advanced Research Institute (SAIT) and Samsung Japan Research Center (SRJ) claimed in Nature-Energy that they had developed a high-performance all-solid-state battery. The cycle life of this battery is more than 65,438+0,000 times, and the electric car can travel 800 kilometers with one charge.
Last year, Samsung also participated in the investment in Solid? Power. And BMW 20 17 started, just like Soild? Power*** develops solid-state batteries together. Whether the vulcanization route can produce results as soon as possible also tests the endurance and strength of these enterprises.
But as far as the slow manufacturing process of Toyota solid-state batteries is concerned, we know that there is still a long way to go before mass production.
Toyota's solid-state batteries must be produced in an ultra-dry and water-free environment. It is made in a transparent box called a glove box. Workers put their hands into the box through rubber gloves tightly embedded in the box. Obviously, this is still in the laboratory stage, which is far from mass production.
Keiji? Keita also cautiously stated that Toyota is still expected to achieve a "limited quantity" of production in 2025. However, due to the small scale of production, the initial cost will be high. So in the first few years of production, the output of this solid-state battery will be very low. Moreover, Toyota's goal is that this battery can still maintain 90% performance after long-term use (30 years), which makes the research and development of this battery more complicated.
On the whole, at present, major car companies are stepping up the research and development and industrial layout of solid-state batteries, and Samsung SDI, SKI, LG Chem, Massachusetts Solid Energy SES, QuantumScape, etc. are also making new breakthroughs in the field of solid-state batteries, and there will be new achievements from time to time.
Domestic enterprises including Huineng Technology, Ganfeng Lithium Industry, Tao Qing Energy, Wanxiang 123 and Wei Lan New Energy are also building solid-state battery production lines, and some of them have even been put into production. After 2025, the card war of the next generation power battery has already quietly begun.
However, the practical application prospect of solid-state batteries seems to be in 2025~2030. Any over-optimistic estimate and forecast needs to be calm in the face of reality.
As analyzed by CICC, the current lithium battery system can reach the battery life of 800~ 1000km after iteration, which can meet the demand. In addition, with the cooperation of supply chain and scale effect, the parity between fuel vehicles and pure trams can be realized by 2025. On the one hand, the high endurance of 1000~ 1400km promoted by solid-state batteries is limited, which is not as important as the convenience of charging network in reality; On the other hand, the high cost of solid-state batteries also leads to the low cost performance in 5~ 10 years.
The future prospect of solid-state batteries is very attractive. According to the calculation of BOC International, the global demand for solid-state lithium batteries is expected to reach 1.7 GWh, 44.2GWh and 494.9GWh respectively in 2020, 2025 and 2030, and the global market space for solid-state batteries is expected to reach 1.50 billion yuan in 2030. However, the reporter believes that solid-state batteries will not dominate in 10 years.
Text/Wang Xiaoxi
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