Recently, Toyota Motor and Japanese petrochemical giant Idemitsu Kosan Co., Ltd. (hereinafter referred to as “Idemitsu”) reached a cooperation agreement. The two parties will jointly develop mass production technology for solid electrolytes and announced that they will reach practical use in 2027-2028. ization goal and mass production as soon as possible.
At the press conference, Toyota President Tsuneharu Sato said excitedly that the two companies will work together to steadily improve their ability to mass-produce solid-state batteries.
In recent years, Toyota has frequently announced progress in solid-state batteries, from durability issues to cost control, to announcing the scale and time of mass production. It seems that it is confident and inevitable. .
Compared with today’s mainstream liquid lithium batteries, solid-state batteries have obvious advantages in terms of safety, energy density, volume, and cost after mass production. The superposition of multiple advantages has great advantages for new batteries. The future development of energy vehicles and even flying cars will have a decisive impact. It can be regarded as a disruptive innovation in the power battery industry and one of the important directions for the future development of batteries.
But based on the information currently available and the technical level of each company, the current battery is still far away from Toyota’s slogans such as “extending the driving range by 2.4 times” and “charging for 10 minutes to drive 1,200 kilometers”. , there is still an obvious distance.
Get rid of the shackles of the chassis
In 1991, Sony released the first commercially available lithium battery in human history. Because of its energy density and reasonable cost, which are about 2 times that of previous nickel-metal hydride batteries, lithium batteries quickly became the mainstream solution in the battery industry, achieving A revolution in the battery industry.
Now, more than 30 years have passed, and the research and development and manufacturing of liquid lithium batteries are close to the ceiling. The industry generally believes that the theoretical upper limit of the energy density of liquid lithium batteries is around 350Wh/kg. However, most of the current large-scale commercial liquid lithium batteries have an energy density close to 300Wh/kg, but it is difficult to break through. But even if there is a breakthrough, the ceiling is relatively limited, which is one of the reasons why various battery manufacturers are intensively developing solid-state batteries.
In principle, solid-state batteries are not complicated. Traditional liquid lithium-ion batteries are composed of positive and negative electrodes, separators, and electrolytes. Because of the concentration difference, lithium ions continue to circulate between the positive and negative electrodes. It moves to achieve charging and discharging, so this kind of battery also has a very vivid description, called “rocking chair battery”.
The solid-state battery replaces the electrolyte and separator in the liquid ion battery with a solid electrolyte, that is, the path for ions to move back and forth becomes a solid state. In the solid electrolyte, the moving speed of ions Faster and more stable, enabling safe and fast charging.
Safety and higher energy density are the most obvious advantages of solid-state batteries. Such advantages also give the industry unlimited imagination for future development.
Mr. Q, the editor-in-chief of an automotive media, told “See the World” that because solid-state batteries use solid electrolytes to replace the organic solvent electrolytes in existing batteries, their safety has been significantly improved: Electrolysis The liquid itself is flammable and volatile. During charging and discharging, energy control and stability are often worse, which is one of the reasons why some new energy vehicles will spontaneously ignite; while solid electrolytes are usually more stable, “as long as they strictly follow the standards If implemented, it is possible for solid-state batteries to never catch fire or explode.”
Theoretically, the energy density of solid-state batteries can reach up to 700Wh/kg, which is fully double the theoretical value of liquid lithium batteries. Higher energy density means that more energy can be provided with the same volume. It also means that solid-state batteries can use smaller volumes to achieve the range of today’s liquid batteries, which has an impact on safety and vehicle layout. Profound.
According to Mr. Q, due to the large size and bulkiness of liquid batteries, the batteries of most new energy vehicles will be placed in the chassis, and the chassis is prone to scratches. Once a major accident occurs Scratches or severe collisions may create potential safety hazards even if they do not immediately affect driving safety. Therefore, electric vehicle bottom scraping test procedures have been added to the 2024 draft of the China New Car Assessment Program (C-NCAP).
Once the battery size is reduced, it does not have to be installed on the car chassis or close to the chassis – this is not only safer, but also changes the design idea of the internal layout of new energy vehicles. Tsuneji Sato also said that all-solid-state batteries will give car companies greater freedom, making it easier to create more attractive designs and make favorable settings for the spatial layout of the cabin.
More than 30 years have passed, and the R&D and manufacturing of liquid lithium batteries has reached its ceiling.
Alliance of Transformers
If we take a longer-term view, solid-state batteries may also be able to promote the development of the flying car industry. In order to achieve longer battery life, flying cars have to install larger and heavier batteries, and larger and heavier batteries themselves affect the battery life. Improving battery energy density is an important idea to solve this dilemma. This is the biggest advantage of solid-state batteries.
Other problems that currently plague flying cars, such as slow charging and unstable charging and discharging, will also be solved to varying degrees with the large-scale commercial use of solid-state batteries.
It is precisely because solid-state batteries are so strong that Toyota has boasted about Haikou. According to the “Nihon Keizai Shimbun” report, Toyota plans to increase global sales of pure electric vehicles to 1.5 million units by 2026. Increase to 3.5 million vehicles by 2030.
Solid-state batteries were once considered an important support for Toyota’s “turnaround”. The Japanese media once used the saying “vehicle all-solid-state batteries will be the ‘decisive battle’ between Japan and Germany” to describe the development of solid-state batteries. importance. According to Toyota’s estimates, a car equipped with an all-solid-state battery can achieve a range of 1,200 kilometers on a 10-minute charge. This is a qualitative improvement compared to Toyota’s existing model bZ4X, which has a theoretical range of 600 kilometers on a 30-minute charge.
The cooperation between Toyota and Idemitsu is a collaboration between two companies that are in urgent need of transformation. Today, the 86-year-old Toyota seems to be somewhat senile. An old company that once aspired to be the world’s number one car company, in the era of new energy vehicles, Toyota seems to have left only a staggering and lonely figure.
Idemitsu is a petrochemical-based company. Its president, Shunichi Muto, said that since the oil crisis in the 1970s, out of concerns about oil depletion, the company has been researching alternative energy sources and materials, and many of its results have been successfully commercialized.
At present, using sulfide as a solid electrolyte is one of the research directions of solid-state batteries, and sulfide itself is a by-product of the petroleum industry, which is also an important reason for the two parties to join hands this time.
It is understood that the two companies have established a special working group covering technology, procurement, logistics, production technology and other departments for this cooperation. They will use high capacity, high output power and easy implementation The “sulfide-based” solid electrolyte is the target.
Toyota stated that the patent for the material composition of the solid electrolyte is owned by Toyota, and the material made by Idemitsu has three characteristics: strong water resistance, good ion conductivity, and good flexibility. The two companies’ Materials research and development technology, Idemitsu’s material manufacturing technology, and Toyota’s battery mass production technology will be combined to achieve full process coverage.
Public data shows that the number of patents of the two companies in all-solid-state batteries and their material sulfide solid-state electrolytes are among the top in the world. As of June this year, they have “sulfide” and “solid-state” patents. There are about 200 patents related to “Electrolyte” in total, and Idemitsu’s number of patents related to lithium sulfide ranks first in Japan.
Of course, another big issue before solid-state batteries is how to control costs. According to estimates from the Japan Science and Technology Promotion Agency, the manufacturing cost of all-solid-state batteries (sulfide type) is 60,000-350,000 yen per kilowatt hour (approximately RMB 29-170 million), which is 4-4 higher than existing lithium-ion batteries. 25 times.
“The wolf is coming”?
Solid-state batteries are considered to be Toyota’s trump card that can counterattack, but unlike in business war stories, which are traditionally not revealed until the last minute, Toyota’s trump card is more like a human The well-known “brand name” Toyota, which is considered by the outside world to be relatively slow in its electrification transformation, has repeatedly announced that it will launch an attack on the best technology in the current battery field. The contrast between it can’t help but make people feel interesting.
Every once in a while, Toyota will bring the latest advances in solid-state batteries to the forefront, just like the story of “The Wolf Cried”. But the difference is that Toyota may not be the child in the story, but more like the “wolf” that will appear at some point. Mr. Q said that Toyota may be really powerful, but it may also be marketing. Before 2027, , I’m afraid no one can give an accurate answer to this question.
Safety and higher energy density are the most obvious advantages of solid-state batteries.
Others who hold similar views include Wu Kai, chief scientist of CATL. He said at the 2023 China Automobile Forum in July this year that there are still some urgent problems that need to be solved in solid-state batteries. Even if we look at the world, no company in the entire industry can achieve mass production at the moment, but he also admitted that the technology is indeed It is in the process of change and believes that “as for what will happen in 2027, it is currently difficult to predict.”
Mr. Q told “Look at the World” that compared with China, Japan is making a nationwide effort to develop and even “bet” on solid-state batteries, so it has advantages in theory and the number of patents, “Toyota In terms of the number of patents related to solid-state batteries and the technical principles it has mastered, it is indeed ahead of other companies by a certain amount.”
The “Nihon Keizai Shimbun” also reported in 2019 that in order to ensure the dominant position of the automobile industry in Japan, the government and private enterprises are working together to make it practical.
However, Mr. Q also said that there is no generational gap between leading companies. The semi-solid batteries that have been delivered and the solid-state batteries that have been out of the laboratory are compared with traditional liquid batteries. This is already a big breakthrough.
The solid-state battery developed by SAIC and domestic solid-state battery start-up Qingtao Energy has completed the loading test, with an energy density of 368Wh/kg; Weilan New Energy delivered the semi-battery to Weilai The energy density of solid-state batteries has also exceeded the theoretical ceiling of liquid batteries, reaching 360Wh/kg; and CATL, known as the “Ning King”, released a battery in April this year that analysts considered to be a “quasi-semi-solid-state battery” “The new product has an energy density as high as 500Wh/kg.
The current domestic R&D and iteration speed is very fast, and domestic new energy vehicles continue to sell well. Domestic automobiles can rely on the rapid mass production model to achieve multiple iterations in the short term, which means Well, to take a step back, even if Toyota really builds a solid-state battery in 2027, there may not be much time left for Toyota to enjoy the benefits of solid-state batteries exclusively.