A technology that is half a step ahead of the market is a pioneer, but ten steps ahead may be a martyr. Lithium batteries with multiple technical routes cannot escape this rule.

On July 5, South Korean research organization SNE Research released the latest TOP10 ranking of the global power battery industry. From January to May 2023, Ningde Times and BYD will continue to occupy the top two positions, with shares of 26.3% and 16.1% respectively, and a year-on-year growth rate. In the forefront of all power battery suppliers. Of South Korea's "three outstanding" LG, Samsung and SK On, only LG Energy maintained a small increase, Samsung shrank by 0.7%, and SK On lost 2.1% of its territory.

Japan's Panasonic is the only Japanese company on the list, ranking fourth, accounting for 8.9% of the share. But once upon a time, Panasonic was the number one overlord of lithium batteries in the world, "ruling" the market for 10 years.

Although Japanese companies have been left far behind by China, Europe, the United States, and South Korea in the lithium battery and electric vehicle markets, they are extremely "smooth" in the competition for next-generation battery technologies such as solid-state batteries and lithium-sulfur batteries. big. Recently, Toyota, the leader of the global car company, has once again "spoken wild words", announcing the latest progress in solid-state battery technology and commercialization-solid-state battery vehicles will be launched on the market in 2027, and they can travel 1,200 kilometers in less than 10 minutes.

Ever since, some people are worried: Will Toyota copy the back road of China's electric vehicles by relying on solid-state batteries?

If you know enough about the development process of photovoltaic and lithium battery technology routes, you won't worry about it irrationally. Because technically, going from 0 to 1 seems glamorous and great, but actually going from 1 to 100 is the most difficult. This is why many companies choose to take a half-step ahead and run in small steps instead of blindly pursuing the absolute advancement of technology.

The battle of solid-state battery routes, the contest between China, Japan and South Korea

Solid-state batteries are the ultimate form of power batteries and the main line of next-generation power batteries. There is already a global consensus on this point.

At present, global electric vehicles are entering the fast lane. Except for Japanese companies such as Toyota, Nissan, and Honda, which are still half-hidden, Chinese car companies are all in electrified, and major European and American manufacturers have followed suit. The "potential" energy has already emerged. However, car buyers still have concerns about short battery life, slow charging speed, and safety.

Solid-state batteries are an antidote, with many advantages, which can perfectly solve the problems of battery life, safety, and temperature adaptability.

The first is high energy density, which corresponds to the key indicator of battery life. Compared with the current mainstream lithium iron phosphate, nickel-cobalt-manganese ternary cathode materials and liquid electrolytes, solid-state batteries directly replace the liquid state with a solid-state electrolyte, and even remove the middle diaphragm, which greatly increases the energy density. The level of energy density depends on the specific (gram) capacity and operating voltage range of the positive electrode and negative electrode materials. 4.3V is already the voltage limit of liquid lithium batteries, while solid-state batteries have an excellent electrochemical window supporting more than 5V, you can choose higher Positive and negative electrode materials with specific capacity.

More generally speaking, the energy density is directly related to the number of intercalated and extracted lithium ions in a single cycle under the same mass. The ideal mode is that under the same mass, the more lithium ions "transported" per unit time, the better, and the safer the better. Well, the sooner the better.

For example, the positive electrode of lithium iron phosphate, 200Wh/kg is a ceiling, generally only 180Wh/kg. The nickel-cobalt-manganese ternary positive electrode is better than lithium iron phosphate, and the energy density depends on the amount of nickel content. The ternary positive electrode of the 3 series and 4 series has a lower nickel ratio than the 8 series, and the latter can approach 300Wh/ kg, but 300Wh/kg is the limit of liquid lithium batteries. If the number of lithium ions migrated by liquid lithium batteries is 0.5, then the migration number of solid-state batteries can be directly increased to 1, and the energy density can be doubled to exceed 500Wh/kg.

The second is security, which is the easiest to understand. Liquid electrolytes and organic solvents are volatile and flammable, and have poor thermal stability. Once leaked, fire and explosion are inevitable. Moreover, during the charging and discharging process of liquid lithium batteries, lithium dendrites will grow, penetrate the diaphragm, and cause a short circuit. Compared with solid-state batteries, because the electrolyte is solid, the thermal stability is much better.

Finally, solid-state batteries have stronger cycle performance and better stability, which can slow down the process of battery deactivation and degradation, slow down the decline, and greatly improve the cycle and life of lithium batteries. Ideally, the number of cycles can be as high as 45,000. This is very important. The average service life of liquid lithium batteries is only 8-10 years, but after the life of solid-state batteries is extended, the cost will be greatly diluted, and the competitiveness of electric vehicles compared with oil vehicles and hydrogen fuel cell vehicles will be further improved. improve.

Just like lithium iron phosphate and ternary liquid lithium batteries have emerged from thousands of troops, solid-state batteries also have routes. From positive electrode, negative electrode materials to electrolytes, different choices also mean different paths and corresponding to different performances , safety and cost. According to the different commercially available solid electrolytes, solid-state batteries are divided into three camps: polymers, oxides, and sulfides.

Polymer electrolyte has high ionic conductivity at high temperature, good contact, and controllable interface impedance, but the disadvantage is that the conductivity at low temperature is low, the working voltage is higher than 4V, and electrolysis is prone to occur, so it is being abandoned by enterprises; the energy density of sulfide The highest, the best performance, but the highest process complexity, prone to side reactions with air and water; globally, the number of companies using oxides as electrolytes is the largest, as an intermediate route, relatively high conductivity, good electrochemical stability , The cycle performance is good, the preparation environment requirements are low, and it is easier to mass-produce, but because of the high interface impedance, the rate performance is affected.

Many Chinese companies choose the oxide electrolyte route, including Qingtao Energy, Weilan New Energy, and Ganfeng Lithium Industry. Ningde era chose the sulfide with the most technical difficulty and the most complicated synthesis process. In this branch, in addition to Panasonic, Samsung, LG Chem, and Solid Power of the United States, Japan's Toyota is also here.

In addition to performance, cost is the biggest natural moat

The advantage of choosing the sulfide route is that once a breakthrough is made, technical barriers can be quickly formed to achieve dimensionality reduction. However, the time for large-scale commercial use generally predicted by the industry should be between 2028 and 2030.

At this time, if a company shows off its laboratory data, it is mostly just a gimmick.

It must be admitted that Toyota has been immersed in the field of sulfide solid-state batteries for many years. More than 20 years ago, Toyota began to accumulate patents in the field of solid-state batteries. Not only Toyota, but Japanese companies have formed a patent encirclement in the field of solid-state batteries very early. As of March 2022, Toyota has 1,331 solid-state battery patents, ranking first in the world. Panasonic Holdings and Idemitsu Kosan, which are also Japanese companies, rank second and third respectively. Samsung and LG Chem are two Korean companies. The number of solid-state battery patents is also quite large, ranking in the top ten.

However, the essence of lithium batteries is the manufacturing industry. R&D breakthroughs can only determine the transition from 0 to 1 technology, but whether it can be accepted by the market in the end and applied on a large scale depends on the supporting capabilities of the industrial chain and the huge market base available for landing. The process from 1 to 100. Usually, people pay more attention to the former, but tend to underestimate the power of industrialization of the latter.

The unsatisfactory development of power batteries in the United States just shows the value of industrial support. Although the United States is the inventor of the lithium iron phosphate lithium battery, it is Japan that actually commercialized the vehicle lithium battery.

In the 1980s, American physicist John Goodenough followed in the footsteps of British chemist Stanley Whittingham and explored lithium cobalt oxide, lithium manganese oxide, and iron phosphate when lithium metal batteries were difficult to land. Lithium is the three cathode materials, but at that time, fuel vehicles were in full swing, and the market for electric vehicles did not exist at all.

Ten years later, in 1994, Panasonic successfully developed a rechargeable lithium battery. Subsequently, Japanese companies including Panasonic and Sanyo almost monopolized the global consumer electronics lithium battery market. Therefore, when Tesla was looking for lithium batteries for loading, although the consistency, safety, and energy density requirements were not the same as consumer electronics, after comparing many batteries, Panasonic's 18650 cylindrical lithium battery finally stood out. Until 2014, among the top ten power battery suppliers in the world, Panasonic always ranked first.

Although Toyota is striving high in the breakthrough of solid-state battery technology, the technical route of sulfide determines that in addition to performance, cost, industrial chain support, and large market are the key points.

Also take the United States as an example. The United States is a country on wheels. In the Obama era a few years ago, it called for the return of manufacturing and lithium batteries as the core industry. A123 used to be the standard-bearer of lithium batteries in the United States. In 2004, by manufacturing the lithium iron phosphate cathode material into nano-scale ultra-small particles, it greatly improved the rate performance and stood under the tuyere of electric vehicles. In 2009, the U.S. government allocated 250 million U.S. dollars to A123, but because of the high labor costs in the U.S. and the lack of supporting facilities in the industrial chain, it lost money every time it produced a battery, and eventually withdrew from the market.

From the laboratory to the production line, there is a huge and insurmountable gap. In particular, the lithium battery manufacturing chain is long, with more than 20 processes, and the off-line cycle of more than two weeks requires precise control of different processes, materials, and environments, and the operating accuracy has been raised from micron to nanometer. What's more, solid-state batteries with sulfide electrolytes are more demanding on the process.

Not only is there uncertainty in process breakthroughs, but cost considerations are also critical. Compared with liquid batteries, the process of all-solid-state batteries has changed greatly, involving a series of factors such as new equipment, amortization, product quality control, and long engineering verification cycle. Among them, the most difficult sulfide electrolyte solid-state battery has a more complicated synthesis process, which leads to high production costs and huge uncertainties on the road to commercialization.

In the short term, look at semi-solid state, and in the long run, look at lithium-sulfur batteries

Whether all-solid-state batteries can be loaded and scaled up, cost and economy are almost the only factors. If solid-state batteries can help OEMs reduce costs, commercialization will be a matter of course.

According to the calculation of China Post Securities, the cost of solid-state batteries is more than 30% higher than that of liquid batteries. It is estimated that after large-scale mass production of semi-solid batteries, the cost will be 10%-20% higher than that of current liquid lithium batteries. But in fact, this estimate has been quite optimistic. The Energy Chain Research Institute believes that there is still a long way to go to reduce the cost of all-solid-state batteries. From laboratories, pilot lines to mass production, they are facing many challenges such as interface problems, material problems, and engineering problems.

The competition for technical routes is like a horse race, which is often dynamic. Whoever can run out can occupy a place.

Therefore, most domestic power battery companies have adopted the strategy of walking on two legs, and are planning for short-term and long-term deployment. From 2023 to 2024, domestic power battery enterprises will focus on semi-solid batteries and gradually replace liquid lithium batteries. The positive and negative electrode materials will continue to be lithium iron phosphate, nickel-cobalt-manganese ternary materials and graphite; in 2025, silicon-rich and lithium-rich negative electrode materials will be used. It will be applied; in 2028, all-solid-state batteries will enter the stage of mass production and loading, and the negative electrode will use lithium metal with a higher capacity than (grams), and the energy density will exceed 500Wh/kg.

If the all-solid-state battery is "in the pot", then the semi-solid-state battery is already "in the bowl".

For power battery suppliers, it is necessary to not only eat what is in the bowl, but also look at what is in the pot. Semi-solid batteries with an energy density of about 350Wh/kg have gradually begun to land. Qingtao Energy disclosed that the semi-solid battery developed in cooperation with SAIC Motor is expected to be mass-produced in 2025, with a mileage of 1,000 kilometers+; Weilan New Energy has made faster progress and has delivered the first batch of semi-solid battery batteries to NIO. core, the energy density is 360Wh/kg, which is twice that of lithium iron phosphate battery, and it can run 1000 kilometers on a single charge.

In addition to solid-state batteries, lithium-sulfur batteries, another technical route, have also received widespread attention.

The positive electrode material of lithium-sulfur batteries uses sulfur-carbon composites, and the negative electrode is more active metal lithium. Through oxidation-reduction reactions, the movement of lithium ions is completed to realize the charging and discharging process. The specific (gram) capacity of lithium is as high as 3860mA·h/g, and the theoretical energy density is as high as 2600Wh/kg, which is 10 times that of graphite and 18 times that of lithium iron phosphate batteries.

There is also a bigger advantage. Since there is no metal such as nickel, cobalt, and manganese, the weight of lithium-sulfur batteries is lighter. Sulfur in the positive electrode material is also widely available. It is easy to obtain and can be processed from sulfur. Last year, my country's sulfur output was 9 million tons. This determines the low cost of lithium-sulfur batteries.

However, just as solid-state batteries have material, process difficulties, and cost obstacles, during the charging and discharging process of lithium-sulfur batteries, the volume expansion and contraction of the positive electrode sulfur will also increase the risk, although the sulfur-carbon composite partially solves the problem of positive electrode volume expansion and improves However, the stability of the overall cycle still needs to be verified.

There is also a fatal problem. During the charging and discharging process of liquid lithium-sulfur batteries, sulfide will fuse with the electrolyte, causing the battery capacity to drop sharply, directly affecting the life of the battery. Solid-state lithium-sulfur batteries are considered to be able to overcome this technical defect.

Whether it is a solid-state battery or a lithium-sulfur battery, compared with Japan and South Korea, CATL and BYD are not moving fast on the solid-state battery technology route, or they are much lower-key than Toyota.

However, China already has the right to speak in the global power battery industry chain, and has accumulated rich experience in material exploration, technology, and cost control. At the same time, considering that by 2028, China will already have 103 million new energy vehicles, and the number of new energy vehicles is almost eight times that of 2022. These advantages are incomparable to Japan and South Korea, which are lagging behind in electric vehicles.

The conclusion is that semi-solid batteries are viewed in the short term, all-solid-state batteries are viewed in the long term, and lithium-sulfur batteries are viewed in the longer term. The next-generation power battery competition is a confrontation between China and Japan and South Korea, and Europe and the United States will continue to be absent.