【Core intelligent driving】Power battery new brain hole, lithium metal battery can "out of the circle"?

Jiwei Network reported that SES (Massachusetts Solid Energy), an American start-up that develops pure electric vehicle batteries, has recently received about 2% of the capital injection from Japanese car company Honda, and the two companies have signed a joint development agreement for lithium metal batteries as one of the new generation batteries, and focus on mounting them on Honda's mass production vehicles. Honda has not disclosed the specific amount of capital contribution.

Automakers such as Honda are speeding up the development of pure electric vehicles, but the production and procurement costs of batteries that affect the range have become a major problem. Honda strives to develop batteries with high capacity, high durability, and safety, and is developing technologies such as all-solid-state batteries in addition to lithium metal batteries.

"Improving range and reducing costs are two directions for battery material innovation." SES founder Hu Qichao recently gave an exclusive interview to Jiwei. According to public information, SES is scheduled to be listed on the New York Stock Exchange in February this year and will accept investment from Honda as an opportunity to list. The company plans to deliver lithium-metal batteries to automakers in 2025.

Anode Materials: A New Path for Battery Technology Innovation

Out of stock, rising prices, lithium battery industry is also facing the same dilemma as the lack of cores. A few days ago, CATL replied to the Shenzhen Stock Exchange that from the perspective of future capacity demand and the company's existing production capacity, the company's capacity gap in 2025 is not less than 430GWh. As the demand for batteries rises, the upstream material end also rises in price.

Since cathode materials account for the largest proportion of batteries, the price changes of its raw materials including nickel, manganese, cobalt, lithium, etc. have greatly affected the development of battery technology. At present, the price of cathode materials for mainstream lithium iron phosphate and ternary lithium batteries fluctuates greatly, especially the cost of rare metals such as cobalt has remained high. Whether it is the sodium-ion battery released by CATL last year or the cobalt-free battery launched by Hive Energy, it is an alternative to solve the problem of raw material mining and cost of existing lithium-ion batteries.

SES is trying to cut through the negative electrode material, or it will make the old material of lithium metal shine again. Hu Qichao stressed to jiwei network that although the endurance of power batteries is a key part of electric vehicles, its safety and cost are still the focus that cannot be ignored, and how to seek innovation in upstream materials is also the focus of the industrial chain.

At the end of the anode material, the research report of Shanxi Securities pointed out that the anode material for power batteries can be divided into carbon anode material and non-carbon anode material. Carbon-based anode materials can be divided into graphite, hard carbon, soft carbon and graphene and other negative electrode materials, of which graphite materials can be further divided into natural graphite, artificial graphite and intermediate phase carbon microspheres. Non-carbon anode materials include titanium-based materials, silicon-based materials, tin-based materials, nitrides and lithium metal.

Artificial graphite because of its good magnification performance, small volume expansion, high and low temperature performance is beneficial, high cycle life advantages are the current power battery anode mainly used materials, but the application of non-carbon materials is an important route for the development of the post-lithium-ion battery era. For example, the specific capacity of silicon-based materials is about ten times that of graphite, and its cost and capacity density are better than current graphite materials.

"Lithium metal buff"

At present, mainstream lithium-ion batteries use graphite on the negative electrode, but lithium metal batteries use lithium, which is said to achieve several times the capacity of the current battery. However, lithium metal is not a new substitute for the anode material end of lithium-ion batteries, on the contrary, lithium metal performance on the negative electrode material is better than graphite or even silicon, but lithium metal dendrites will puncture the diaphragm or battery cell shell, there is a large safety hazard, so although it came out early, it was not mass-produced.

Driven by the development of electric vehicles, a number of companies such as SES, Enli Power, etc. have begun to lay out on the lithium metal battery track. Among them, SES released the Apollo lithium metal battery at the first SES Battery World event last year, which has a capacity of up to 107 Ah, which is currently the world's largest lithium metal battery with a single capacity, and is also the world's first public display of more than 100 Ah of monomer lithium metal batteries, planning to launch a sample of automotive-grade lithium metal batteries A this year, and officially open the commercial mass production of lithium metal batteries in 2025.

Hu Qichao told Jiwei Network that the use of lithium metal materials can not only improve the mileage, but also reduce the cost of the entire car. For example, if the positive electrode of lithium iron phosphate is combined with lithium metal, the energy density that can be achieved is similar to that of ternary lithium batteries with graphite as the negative electrode, but the cost of lithium iron phosphate is lower.

Hu Qichao cited the battery energy density that can be achieved by the combination of different positive and negative electrode materials, he said that the lowest energy density is the combination of lithium iron phosphate + graphite, reaching about 200Wh/Kg; the combination of ternary lithium + graphite can reach 280Wh/Kg; lithium iron phosphate + lithium metal can reach 300Wh/Kg; ternary lithium + lithium metal can reach 400Wh/Kg.

In view of the fact that the energy density achieved by the combination of lithium iron phosphate + lithium metal and ternary lithium + graphite is relatively close, due to the advantages of lithium iron phosphate in cost and supply chain, most enterprises will choose the combination of lithium iron phosphate + lithium metal.

In order to solve the above safety problems of lithium metal, SES has developed a high-concentration electrolyte, changed the microscopic shape of lithium dendrites, avoided direct piercing of the diaphragm or battery cell shell, in addition, SES also added additives to the negative surface of the electroplated battery, so that the surface formed a protective film and slowed down the growth rate of lithium dendrites.

Hu Qichao pointed out that the reason why traditional liquid electrolytes are unsafe is mainly due to the solvents used in flammable and flammable organic carbonate materials. The solvent of the liquid electrolyte used by SES is the company's self-developed and produced for a long time, and its high concentration makes it non-flammable and safer.

"From the production process, it will be much easier to produce liquid electrolytes than solids, and for the entire industrial chain, it can be quickly introduced."

In addition to the electrolyte, SES has also created Avatar, an artificial intelligence safety software for monitoring battery health, which can warn of battery health for several months in advance and remind users to send warranties to the factory as soon as possible.

Hu Qichao pointed out that Tesla and BYD are rare companies that do both batteries and cars, most of the companies will only specialize in one field, which makes their data more scattered, many times the car spontaneous combustion accident, may be the battery production process has been a problem, such as welding or lamination of mechanical problems. Therefore, this production data needs to be collected and benchmarked against the data. In addition, when the battery is on the car, the owner's car habits and environment will also have a different impact on the entire battery safety situation, and a set of safety software can monitor the battery situation from production to the application of the car in an all-round way to avoid safety hazards and accidents.

Overall, lithium metal batteries are not a subversion of ternary lithium or lithium iron phosphate batteries, but give higher added value.

Lithium metal batteries are concerned by car companies, and it still takes time to get on the car in technology

Compared with other emerging battery technologies, the production process of lithium metal batteries is very similar to that of existing lithium-ion batteries, so it is easier to import in the industrial chain and is attracting the attention of OEMs.

At present, SES is working with General Motors and Hyundai Motor to launch A samples of automotive-grade lithium metal batteries this year, and officially open the commercial mass production of lithium metal batteries in 2025.

Hu Qichao told Jiwei Network that general car companies need to go through a process to put new battery technology on the car: A sample - B sample - C sample. The verification cycle of sample A is about two years, sample B and sample C are one year each, and the whole verification cycle lasts 4-5 years.

According to SES's plan, B sample will be launched in 2023, B sample, although the same as A sample, but based on the same technical indicators and size requirements, the requirements for capacity and quality control capabilities will be higher. The B sample on-board test is the C sample stage, which includes the battery performance under different conditions, such as high and low temperature, acceleration and deceleration, car entertainment, etc.

Hu Qichao revealed that at present, SES is still in the A sample stage, and will grind the first sample for a period of one year, including safety, high temperature, low temperature, slow charge and slow release, fast charge and fast release, charge to 90%, charge to 80% and other details of the test, and continue to optimize based on the test results, which may require modification of the positive electrode, electrolyte, negative electrode, etc.

He said that most of the challenges faced by SES come from the details, from the A sample to the C sample process will have a variety of small problems, any battery company to mass production on the car, need to go through such a long process.

In 2019, SES has built a pilot line at the Jiading plant in Shanghai and is currently upgrading to a super factory, which is scheduled to be completed in 2023 with a total area of 30,000 square meters, and the production capacity after completion will reach 1GWh, which will be the world's largest lithium metal battery factory. Hu Qichao pointed out to Jiwei Network that the production capacity of 1GWh is generally applicable to the stage of A sample to B sample, and the real production needs at least 10GWh or more, so the construction of the Shanghai Jiading factory is still more for sample testing considerations.

In terms of global layout, SES has reached cooperation with GM, Hyundai, SAIC and Geely. At present, the Boston base is mainly engaged in material development and software development, and Shanghai Jiading mainly does product development, battery cell development, production process development and cooperation projects with car companies, such as A sample joint development agreement project.

In the future, in addition to American car companies, car companies in China, Japan, Germany and South Korea will land at the Shanghai Jiading plant. SES plans to build a smaller plant similar to Jiading in South Korea, mainly for the development of A samples for U.S. car companies.

It is worth mentioning that SES will establish a joint venture with GM to control the risks of both parties.

"We found that the more effective supply method at present is the joint venture between battery companies and car companies, and this model is gradually becoming a trend, such as LG and GM joint venture to establish battery factories, SK and Ford, Ningde and SAIC." Hu Qichao pointed out that "the establishment of a joint venture factory is conducive to the joint risk of both parties, and can also ensure the battery delivery cycle and quantity." ”

(Proofreading/Sharon)