Produced | Tiger Sniff Car Group
The author | Master Zi Nan
Editor| Post Zhang
"We will become the next Ningde era."
A person in charge of R&D of a solid-state battery company made a vision of the scene after the company developed a solid-state battery when communicating with Tiger Sniff.
The solid-state battery envisioned by the industry can break the shackles of range anxiety, charging anxiety, and safety of liquid battery vehicles.
"Charging and discharging tens of thousands of times is not exhausted, the battery life can be longer than the life of people, full charge as long as a few seconds, and the energy density can reach 700Wh/kg." Solid-state batteries, because of their performance far exceeding those of liquid lithium batteries, are regarded as the core of the next industrial revolution by industries such as automobiles and energy storage.
Frank Brommer, head of Volkswagen's Battery Cell Center, described solid-state batteries as the "terminator" of lithium-ion equivalent batteries, the end point of human energy equipment development before controlled nuclear fusion was realized.
From oak ridge national laboratories in the United States and the Chinese Academy of Sciences to start-up companies such as Toyota Motor, CATL, Panasonic and Solid Power, the smartest group of people in the entire new energy industry are tackling this problem.
Lithium battery "grandfather", Nobel Prize winner Goodnav
"The first person to be created was Prometheus of the new energy industry," the person said. He thinks he's doing something great with great market potential. The influence of this matter is equivalent to refining the elixir of immortality and then selling it to everyone at the price of cold medicine. "It's cool, no one would refuse to pay for it."
Industry leaders are racing against the clock to come out on top in the next industrial revolution. Some companies have re-given the timeline of solid-state battery installation, Toyota believes that it is 2030, the timeline given by the CATL era is around 2025, and the timeline of LG Chem and QuantumScape is in 2024. In addition, BMW, Ford and other car companies have said that they will launch prototypes equipped with solid-state batteries around 2025.
The pie is big and looks delicious, but not everyone can eat it. One investor broke the cold water on this dream, "We don't invest in companies that only do all-solid-state batteries, that's gambling."
"After Weilai released the 150-degree battery, our investors asked us about the progress every three forks and five minutes, we wanted to tell investors that they were bragging, but they couldn't say it, we only had a dozen test lines, battery charge and discharge for several hours at a time, testing a thousand times to get a month or two, which is so fast", another solid-state battery company insider told Tiger Sniff, similar to the test battery charge and discharge life of the production line, Ningde era has thousands.
"In our opinion, their technical route is problematic, and they burned several times in the laboratory stage, and they are now anxious internally," the person revealed what he learned about the current state of research and development of a company that provides 150-degree batteries for NIO.
Solid-state batteries are the biggest pie in the automotive industry after L5 autonomous driving. Autonomous driving describes a story of liberating humans from the hustle and bustle of travel, and the story of solid-state batteries has changed the way humans store energy. Both belong to the "once and for all" technology, but in terms of difficulty in achieving it, it is higher than the moon landing, at least humans have successfully landed on the moon, and the solid-state battery is still in the laboratory stage.
The scientists at the forefront of solid-state battery research and development know each other well, and even some are brothers, and they often pass on progress to each other. One of them expressed a pessimistic attitude toward Tiger Sniff: "Can't make it, or can make a performance that is not very good, the car can't use it."
"Loading solid-state batteries is our lifelong dream."
Why can't it be built?
The entire history of solid-state batteries is written by most failures, compromises and a small number of insistences.
In 2017, the American electric vehicle company Fisker released a patent for a solid-state lithium battery that had just completed the application: charging for 1 minute and lasting 800 kilometers. This technical indicator is still appalling.
Founder Henrik Fisker vowed in an interview that solid-state lithium batteries will be mass-produced in 2023 at a price of only one-third of lithium batteries. In 2018, Henrik Fisker said the company tackled the solid-state battery problem, and the final design will be announced within months.
But by 2021, Henrik Fisker said he had abandoned the solid-state battery program altogether.
"It's a technique where when you feel like you've done 90 percent and are almost there, and then you realize that the remaining 10 percent is a lot more difficult than the previous 90 percent." So now, we're completely abandoning solid-state batteries because we really can't land on the ground. "I personally believe that no matter what form of mass production, solid-state batteries will take at least 7 years." ”
Fisker's "head iron" led to the ultimate failure. In the solid-state battery track, more entrepreneurs, choose to compromise.
Hu Qichao, founder of SES, a company that makes hybrid lithium metal batteries, described another story of exploring the next generation of battery technology routes.
Hu Qichao's mentor worked on solid-state batteries from 1996 to 2012. Hu Qichao's own doctoral thesis is also an all-solid-state battery research. After starting his business in 2012, he found that there are still many basic problems in all-solid-state metal batteries, such as positive and negative interface impedance, lithium-ion conductivity and so on.
These problems greatly reduce the charge and discharge performance and life of solid-state batteries.
"People who do scientific research don't talk too absolutely, but all-solid-state batteries are difficult to make, and the problems we encounter are fundamental chemical problems, and these kinds of problems cannot be solved by time," he said.
At that time, startups like SES chose to switch technology routes. The reason is simple, investors can allow startups to challenge process problems, but the basic science level of the problem, investors can not accept. Based on the suggestions of the capital and his own development considerations, Hu Qichao finally chose to abandon the solid-state battery route and do hybrid lithium metal batteries.
"It may take ten figures like Einstein, rather than ten mature scientists, to solve these basic chemical problems, and now everything on the periodic table has been tried, and solving the basic problem is equivalent to adding other elements to the periodic table," the aforementioned person told Tiger Sniff, the existing chemical system can not break through the bottleneck of solid-state batteries.
Under such a premise, except for some startups with a few key patents, most other startups have taken the research and development of solid-state batteries as a second solution. The most fundamental research on basic chemical problems is mainly carried out in scientific research institutions and giant companies.
Confined to the bottleneck of basic chemistry, solid-state battery research and development institutions have not reached a consensus on the most basic technical route.
At present, the technical route of solid-state batteries is divided into polymer, sulfide and oxide routes. Among them, European and American enterprises focus on the oxide and polymer technology route; Chinese enterprises focus on the oxide technology route; Japan and South Korea are heavily sulfide technology route.
There are corresponding technical difficulties in these three technical routes. The polymer electrolyte needs to be heated to 60 ° C to obtain sufficient conductivity; the conductivity of lithium ions in the oxide electrolyte is much lower than that of the liquid; the conductivity of lithium ions in the sulfide electrolyte is similar to that of the liquid but easy to oxidize to produce toxic gases.
In addition to the difficulty of electrolyte manufacturing, the problems of solid-state batteries also include poor cycle performance, reaction mechanism and mechanism of solid-solid interface, and rechargeability of lithium anodes.
At present, in the industry's view, the most likely to take the lead in mass production of solid-state batteries is Toyota Motor, Toyota has the world's largest number of solid-state battery patents, toyota alone the number and quality of patents far more than China combined.
As early as December 2017, Toyota had said that it would start producing solid-state batteries in early 2020, but in 2019, Shigeki Terashige, head of Toyota's research and development department, said that Toyota would only launch an electric vehicle powered by solid-state batteries at the Tokyo Olympics Technology Exhibition, and would not sell vehicles using solid-state batteries until 2030.
Toyota previously exhibited a sample of a solid-state battery
"We will produce cars equipped with solid-state batteries and show the product in 2020, but the time for mass production of solid-state batteries will be slightly later," he said. ”
But in 2022, Toyota's all-solid-state battery car has not been unveiled. "Toyota's technical route is the highest performance ceiling, but Toyota has not solved the problem that sulfides are prone to harmful gases," the person told Tiger Sniff.
In addition to Toyota, companies that are currently announcing progress in solid-state battery research and development are also widely questioned. "For example, QuantumScape claims to have solved the lithium dendrite problem through ceramic materials, but from the samples we got, this solution has a new problem, and the conductivity of ceramics is very poor."
Domestic companies such as Ganfeng Lithium and Huineng Technology have also encountered research and development problems in solid-state batteries before. Among them, Ganfeng Lithium announced at the 2020 performance briefing that the energy density of the second-generation solid-state battery it developed exceeded 350Wh/kg, and the cycle life was close to 400 times.
But in fact, the cycle life of 400 times is not even half of the national standard, let alone mass production loading. The products of solid-state battery companies such as Qingtao Energy and Huineng Technology have large problems in cycle life or charge and discharge performance that cannot be broken.
"These problems seem to be a millimeter of difference, in fact, lost thousands of miles, now the companies on the market are not reporting good news, such as those who dare not disclose their own volume data of the battery, the volume is often problematic, it seems that the weight energy density is very good, but the energy and power divided by the mention, the performance is very ugly, take the charge and discharge performance to say things, and can not answer the problem of energy density", the aforementioned person said.
"Battery mass production loading is the need to give A, B, C three kinds of samples, these samples need one to two years to verify the reliability of the car will be loaded, if a company says that it can be loaded before 2025, then it must have completed the laboratory stage of research and development work, but according to my understanding, now most battery companies in the laboratory to create solid-state batteries, performance has not yet reached the standard of the sample."
"The biggest difference between now and before is that solid-state battery technology has advanced, and people have identified problems that hinder their commercialization, which is enough to make us feel optimistic," a more optimistic person believes, at least the industry already knows the difficulties faced by solid-state batteries, and the rest is just a solution.
However, the person did not tell Tiger Sniff how long it would take to solve the problem.
Can it be built and used?
The manufacture of all-solid-state batteries is only the first step, and the automotive industry needs the "elixir" to become the price of cabbage.
"When I was an undergraduate, my teacher told me that the research and development of automobile manufacturing is the most difficult, aerospace, semiconductors and other fields seem to have high technical barriers, but they can develop at any cost, cars can't do it, cost and service life are crucial," a solid-state battery research and development engineer told Tiger Sniff.
According to the person, at present, the solid-state battery products of some head companies can be applied in mobile phones, drones and other fields, but they still face many technical problems and engineering problems in the automotive field.
The first is battery life. Mobile phones and other 3C products on the battery charge and discharge life requirements of about 600 times, drones are 200 times, regardless of the cost, the existing solid-state battery samples can meet the performance requirements. However, in the automotive field, the national standard's life requirement for power batteries is more than 1,000 times. And the solid-state battery that only reaches the national standard cannot compete with lithium batteries with a charge and discharge life of more than 3,000 times.
There is also the problem of how to make the battery size larger and integrated. "We can only make a single sample now, but in the end, making battery packs and battery packs will face new technical difficulties, just like building blocks, you have a block, and you need to continue to consider how to build blocks into a house."
Another point is the manufacturing conundrum. Usually, existing lithium batteries have different sizes and materials, but the common rate of different battery product production lines can reach 60%. All-solid-state battery is a new system, how to design an automated solid-state battery production line, is a problem in front of everyone.
Taking the lithium metal materials used in the next generation such as solid-state batteries as an example, the material is extremely sensitive to moisture and oxidation grouping in the air, and the insulating objects generated by the reaction will directly affect the electrochemical properties of the finished product. More seriously, if the lithium metal material is accidentally in contact with water, a violent thermogenesis reaction will occur to trigger deflagration.
QuantumScape's solid-state battery samples, as thin as paper
This makes lithium metal very demanding on the operating process, equipment and environment of the transport, storage and processing process. "This means that the materials required for solid-state batteries need to be prepared in a vacuum, even in some chemical gases, and the requirements for conditions such as temperature are extremely high."
Another elemental platinum, which can improve the stability of solid-state batteries, has always been considered by the industry to be an element that is not suitable for mass production and application, because the cost is too high. In addition, lithium-rich cathodes and other materials have become the consensus of the industry on the technical route. But at present, it is basically stuck in the stage of knowing to use this and not knowing how to scale.
Zeng Yuqun, the founder of NINGDE Times, also said in an interview that the ion diffusion speed in the solid electrolyte required for all-solid-state batteries is only one-tenth of that of the electrolyte, and if you want to improve the energy density, you can only nanoscale the solid particles, which is also a process problem brought by solid-state batteries.
The person revealed that building such a strict solid-state battery production line is a systematic project, in addition to the need for multiple manufacturing links to optimize the design, but also need to design new manufacturing equipment.
For manufacturing giants such as Toyota and BMW, the research and development of new production lines for solid-state batteries may be achieved as scheduled, but for start-ups that lack the ability to manufacture key components from scratch, the manufacturing threshold is a dead end.
Together, these factors drive up the cost of solid-state batteries.
In the 1990s, when oak ridge national laboratories in the United States created the electrolyte of all-solid-state thin-film batteries, some people calculated the cost of mass production of related materials. "According to the current 70-degree calculation of an electric vehicle, the cost of an early all-solid-state thin-film battery that is enough to equip a car is more than $400 million," the person said.
Even after the manufacturing process is improved, the cost of all-solid-state thin-film batteries is still dozens of times higher than that of ternary lithium batteries.
"We are now doing a small sample in the laboratory environment, it will cost tens of thousands, and the final finished product we estimate the cost is also 1.5-2 million yuan," the solid-state battery developer told Tiger Sniff.
At present, the battery equipped in the mainstream consumer market electric vehicles, the maximum cost will rarely exceed 150,000.
At present, the automotive industry generally believes that after the mass production of solid-state batteries, the power batteries used in automobiles will diverge. High-priced first-class models use high-cost solid-state batteries, and low-end models use ternary lithium batteries and lithium iron phosphate batteries.
But such an idea still requires solid-state batteries to achieve cost reduction, although this is a rigid problem that can only be solved by burning money.
"How long it will take us to reach mass production is just a matter of how much we invest." One U.S. stock analyst once said, "In the case of chip manufacturing, most of the restrictions, including those that were once described as technically impossible, have been overcome by increasing funding." The recent growth of the electric vehicle market means that more money can now be allocated to bring solid-state batteries to market. ”
But reinventing a disruptive industry doesn't require the same amount of money as developing a new product. In 2021, Toyota said that it will continue to invest $13.5 billion in the field of solid-state batteries, and BMW, Ford and other car companies have chosen to bet on startups with a small number of patents. In China, Ningde Times, BYD and other enterprises that are in a leading position in the field of liquid batteries are also continuing to invest.
There is luck in this process, no one knows where Einstein will be in the field of batteries, and the only way is to increase the probability of success by burning money. "No one has full certainty, no one wants to give up, just continue to burn, solid-state batteries can burn money is not weaker than aerospace," one investor told Tiger Sniff.
Without solid-state batteries, electric vehicles can also develop
The increase in battery energy density is different from the growth mode of integrated circuit capacity, the energy density of energy storage batteries is step-by-step, and when the new battery material system is determined, the theoretical energy density of the battery has been determined. Therefore, only by inventing a new material system can the leap in battery energy density be possible.
The last time the battery material system was replaced, lithium batteries appeared and surpassed lead-acid batteries. It is precisely because of the application of lithium batteries that we can bid farewell to "big brothers" and use smart machines.
However, if the solid-state battery is not played, will the electric car not develop? Of course not.
At present, the energy density of liquid lithium batteries is still increasing at a rate of about 10% per year.
At the beginning of 2021, Xiang Yanhuo, president of the passenger car solution department of CATL China, said that CATL plans to increase the energy density of lithium iron phosphate batteries to 200Wh/kg-230Wh/kg through the design and excavation of lithium iron phosphate material system.
In addition, BYD has also said that there is still room for improvement in lithium iron phosphate battery materials, and the energy density of the monomer will continue to be improved through the optimization of the material system and process.
The Ministry of Industry and Information Technology previously gave the power battery performance improvement guidelines
However, from the perspective of the Ningde era, the future energy density of lithium iron phosphate batteries will start more from the battery cell structure. According to Xiang Yanhuo, CATL is currently developing a second-generation platform-based CTP battery system, which is scheduled to be put on the market in 2022-2023.
On the technical route of lithium iron phosphate, the ultimate solution in the future may be a cell structure similar to the CTC (Cell To Pack) technology of the Ningde era. CATL expects to apply CTC technology to vehicles in 2025.
To put it simply, this idea is still very rough, that is, since the battery has not grown much, it is necessary to find a way to stuff as many batteries as possible into the car under the premise of ensuring safety.
The future of lithium iron phosphate is uncertain, and improving ternary lithium battery materials has become another breakthrough path. At present, LG Chemical and Ningde Times and other manufacturers are exploring ultra-high nickel ternary lithium batteries, quadrangle batteries and 811 batteries are the products of this technical route. By increasing the proportion of nickel in ternary lithium batteries, the energy density of the battery can be further increased and the cost of raw materials can be reduced.
According to a person close to the Ningde era, the energy density of ultra-high nickel batteries is expected to reach 350Wh/kg in the future. However, after the nickel content exceeds 90%, the thermal stability of the battery will decline rapidly, and the capacity retention rate will also begin to decline. That is, security is reduced and easier to decay.
At present, the main way to improve the safety of high-nickel ternary batteries is to improve their structural stability. By doping with magnesium, titanium and other elements and coating with metal oxides to stabilize the layer structure of the battery. However, this solution is not perfect, the amount of doping and coating will greatly reduce the capacity of the material, too little can not be a good stability of the structure of the material, so it is impossible to fundamentally solve the safety problem of high nickel ternary materials.
In this case, a transitional scheme that can maintain the energy density of the battery cell and take into account the safety has emerged - the solid-hybrid battery. The safety of the battery can be greatly improved by replacing the electrolyte in the battery with a solid electrolyte mixed with the electrolyte.
According to the above-mentioned person, when the electrolyte accounts for 5%-10% of the overall electrolyte, the safety of the power battery can be basically solved. However, how to improve the energy density of solid-mix batteries is still a problem. "The density of the electrolyte is close to the density of water, but the density of the solid electrolyte is much larger than the electrolyte, and if the solid electrolyte is added to the same volume of battery, the weight of the battery will increase, which means that the energy density per unit mass decreases," he said.
However, if the lithium metal material can be applied smoothly, the energy density problem of the solid-mix battery will be solved. In the short term, liquid lithium batteries have not yet reached the performance ceiling. Electric vehicle technology will only stall when liquid lithium batteries reach the ceiling and solid-state batteries cannot be commercialized.
The development of revolutionary technologies will not happen overnight. Before the mass production of solid-state batteries, we will also see Tesla's 4680 batteries, Ningde era and LG's ultra-high nickel batteries. Some people will think of such improved technology as a liquid battery "back to light". But 10 years ago, the progress of liquid batteries was also beyond imagination. Whether the idea of solid-state batteries can be realized still needs time to answer.
"We believed that solid-state batteries would be put in the car, which is why we have persisted to this day."
Resources:
"How long will it take for solid-state batteries to really get on the car" - Li Wenbo
"Research Progress of All-Solid-State Thin Film Batteries" - Wu Yongmin
"Power Battery Technology Development Bottleneck Analysis and Suggestions" - Zhang Wei
"Research Status of a New Generation of Electric Vehicle Power Batteries" - Tao Sicheng