The positive arena is changing, understand quaternary materials in one article

While the capital market is cheering for investment in new energy vehicles, car owners in reality are worried about whether their electric vehicles will spontaneously ignite for no reason.

According to Yiou Think Tank, there will be a total of 27 spontaneous combustion accidents of electric vehicles in China in 2020, including parking, driving, charging, and after accidents. Among them, the proportion of parking spontaneous combustion exceeds 44.4%.

Behind the spontaneous combustion, most of it is the thermal runaway of the ternary lithium battery.

High energy density and safety are put on both ends of the balance. How to combine the two is an unavoidable problem for new energy car companies.

Last year, BYD and CATL introduced innovative technologies for lithium iron phosphate battery packs. By reducing the number of parts and increasing the volumetric energy density of the battery packs, both safety and endurance goals were achieved.

However, this scheme has many limitations. High CTP often requires battery cell companies to form cooperation with vehicle manufacturers from the chassis stage, and jointly customize batteries. Due to the importance of the chassis and the scattered demand for supply guarantee, car companies need to measure the Pros and cons of deep binding.

Now, a new solution has appeared again, quaternary materials. Will this material, which is safer, more stable, longer-lasting, and lower cost than the high nickel ternary, become a major trend in the future? Who are mass-producing quaternary batteries nowadays?

01 Iron and Lithium "Back to Light"

According to GGII data, the installed capacity of lithium iron phosphate batteries in my country reached 8.8GWh in May 2021, accounting for 63.6% of the total installed capacity, far exceeding 5.0GWh for ternary batteries.

As early as the last 10 years, lithium iron phosphate started to bottom out and rebound. Relying on Wuling Hongguang, domestic Tesla Model 3, BYD Han EV and other explosive models and leading new energy car companies have launched models equipped with lithium-iron batteries. The installed capacity of lithium iron phosphate batteries has increased.

Behind this, it is inseparable from the battery pack innovation. With the introduction of CTP and BYD blade technology in the past 20 years, the potential of iron-lithium has been further tapped. The efficiency of battery packs has improved and the energy density has improved, and iron-lithium has ushered in a resurgence.

However, compared with ternary, the development prospect of lithium iron phosphate has already appeared bottleneck.

At present, the actual energy density of the iron-lithium single core is close to the theoretical limit, 200Wh/kg. In other words, car companies, if they want to increase energy density, they can only start with volumetric energy density. For example, BYD launched Han with blade batteries. The volumetric energy density of the battery is as large as 229Wh/L and the cruising range is 605km.

The success of BYD’s Han blade battery is more based on the design basis of its C-class car. Han’s wheelbase is 2.92 meters, which reserves a lot of space for battery pack installation, while the wheelbase of ordinary A-class cars is 2.3-2.5 meters. In the relatively limited A-class car, the blade iron lithium is still difficult to make its battery life exceed 500km.

This will limit the consumption choices of some A-class car owners who have a higher endurance preference, and this part of the car owners are the largest consumers of passenger cars in my country. According to the data of the Passenger Association, the proportion of domestic passenger car A-class car sales in 2020 will reach 60 %.

In contrast to the ternary battery, because the ternary positive electrode is still in the rising period of technological iteration, the energy density ceiling of the ternary battery cell is around 300wh/kg, which is still 30% higher than the current level of 240wh/kg.

In the medium and long term, high-nickel ternary batteries are an antidote to consumers' "mileage anxiety".

Owners who have bought new energy vehicles generally have "battery life anxiety", worrying that when driving an electric car, the battery will suddenly run out and lie down.

This worry is not unfounded. At present, the domestic endurance range uses the NEDC working condition standard. When testing the vehicle endurance, power-consuming equipment such as air conditioners, headlights, and audio will be turned off. In addition, this European standard is also difficult to adapt to my country’s complex urban road conditions. As a result, there is a certain gap between NEDC mileage and real mileage.

People will listen to music, turn on air conditioning, and use onboard entertainment systems to improve driving comfort during daily driving, which will consume electricity and affect the vehicle's mileage.

The industry generally believes that taking into account factors such as actual driving roads, air-conditioning conditions and driving habits, a new energy vehicle with a nominal cruising range of 400 kilometers has an actual cruising range of about 280 kilometers, which is equivalent to a 30% discount. In the sub-zero environment in winter, the true battery life of the vehicle may be further discounted.

On the whole, the potential and improvement space of ternary materials are better than that of iron-lithium, and car companies are constantly moving towards higher energy density and high-nickel ternary development.

Except for BYD of All IN Lithium, domestic independent car companies still focus on ternary. Some models such as Roewe and Xiaopeng P7 are also equipped with the same iron-lithium version as a low-end version for consumers to choose from.

For models positioned in the mid-to-high-end market, both domestic and overseas car companies adopt high-nickel ternary solutions. Potentially explosive new cars include Volkswagen ID4, BMW IX3, Ford Mach-E, Jikr 001, Zhiji L7, BAIC Alpha S and so on.

However, Sanyuan is not perfect. How to ensure the thermal stability of the battery and increase the cycle life is an obstacle to the development of Sanyuan.

As the radii of divalent nickel ions and lithium ions in ternary materials are close, with the increase of nickel content, the probability of mixing Li and Ni produced during high-temperature sintering of ternary materials increases rapidly, making it difficult to deintercalate lithium ions, which further makes The specific capacity and cycle performance of the material are reduced and difficult to reverse.

The high nickel ternary element is easy to explode, which is a headache and difficult to solve. When the high nickel material reaches about 200°C, the chemical substances inside the battery begin to decompose to release oxygen atoms, and the lithium battery bulges. At this time, after being mixed with the vaporized electrolyte, it is easy to ignite spontaneously at high temperatures.

According to data from the National Monitoring and Management Platform for New Energy Vehicles, although the fire accident rate of new energy vehicles is 0.9-1.2 per 10,000 vehicles, which is lower than the level of 2-4 incidents per 10,000 fuel vehicles, 80% of them are safe. The accident battery is a ternary battery.

02 Four Elements Rising in the Wind

In view of the various pain points of high-nickel ternary materials, quaternary materials have risen to the challenge.

Each component in the ternary material NCM plays a different role. Nickel (Ni) can improve material activity and energy density; cobalt (Co) is also an active material, mainly stabilizing the layered structure of the material while reducing the mixing of cations, facilitating deep discharge of the material; manganese (Mn) plays a role in the material Supporting function to ensure the stability of the charging and discharging process.

However, when the proportion of nickel increases and the proportion of cobalt decreases, the stability of high nickel ternary materials will be tested, which is mainly manifested in the capacity loss of cyclic charging and discharging and the accelerated degradation of battery capacity under high-temperature environments.

It seems that high nickel and stability cannot be achieved at the same time, until the emergence of the quaternary material, nickel, cobalt, manganese, aluminum, NCMA, solved this big problem.

NCMA, as the name suggests, is one yuan more aluminum (Al) than ternary. The essence is to use Al instead of Co. By doping Al particles in the NCM ternary material, the strength of the Al-O chemical bond formed is much greater than the Ni(Co, Mn)-O chemical bond, which chemically enhances the stability of the positive electrode.

The quaternary material NCMA (nickel-cobalt-manganese-aluminum) is not a brand-new material system but is based on a mixture of the two mainstream ternary high-nickel materials NCM and NCA at this stage. It was originally developed by Un-Hyuck Kim of Hanyang University, South Korea in 2016 Proposed in the year.

The Un-Hyuck Kim team found that the irreversible phase transition voltage of the NCMA quaternary cathode material remained stable after multiple cycles of charging and discharging, with fewer micro-cracks inside the material, and the dissolution of transition metals in the cathode material was not obvious.

In addition, the experiment also compared the 2032 battery pack and found that whether it is 100 cycles at 30°C or 1000 cycles at 25°C, the capacity retention rate of NCMA is about 10% higher than that of NCM and NCA.

In the quaternary material system, the cobalt content can be reduced to less than 5%, and the nickel content can be increased to 90%. Therefore, the energy density of the quaternary battery is also very high. When matched with high-performance silicon-carbon anode materials, the energy density of the battery can be reduced. Raising to a new level of 300Wh/kg, you must know that the current energy densities of high nickel ternary NCM811 and NCA are 260Wh/kg and 280Wh/kg, respectively.

The cathode material pricing model is the "raw material cost + processing fee" model, the raw material price is transparent, generally based on the current price of several metals (including cobalt sulfate, nickel sulfate, manganese sulfate, lithium carbonate/lithium hydroxide). Ferry includes corporate profit, which depends on the cost of the sintering process.

In the mainstream ternary cathode material NCM523, the proportions of nickel, cobalt, and manganese are 43.8%, 33.2%, and 3.6%, respectively, and the proportions of high-nickel ternary NCM811 are 60%, 14.2%, and 1.0%.

Because the price of cobalt sulfate fluctuates greatly, the cost of NCM523 is high and sometimes low, which in turn affects the gross profit rate of cathode material companies, but the impact on NCM811 is small.

At the same time, the processing cost of high-nickel cathodes is also higher than that of low-nickel cathodes, which has greater profit margins. The sintering temperature of high-nickel materials is lower than that of low-nickel, and secondary sintering is required, so the electricity cost will be higher than the latter; during the sintering process, oxygen is also needed, which puts higher requirements on kilns and other equipment, which leads to high nickel In the ternary, the cost of raw materials accounts for less than that of low nickel, and the processing cost is greater than that of low nickel, and the added value of the product is higher.

According to calculations by the new Huaan Power team, the NCM523 industry processing fee is about 40,000-60,000 yuan/ton, while the NCM811 industry processing fee is about 60,000-80,000 yuan/ton.

The use of high-nickel materials can bring about a further decrease in the consumption of each of the four major materials. In order to achieve the same amount of electricity, the amount of high nickel material used is significantly lower than that of ordinary ternary materials. To produce 1Gwh batteries, the amounts of NCM523 and NCM811 required are 1700 tons and 1400 tons, respectively. At the same time, the coating area of ​​the positive electrode decreases, which corresponds to the pole piece The area, diaphragm area, and electrolyte volume decrease.

The quaternary material NCMA has increased the proportion of nickel to more than 90% on the basis of NCM811, while cobalt has further dropped to less than 5%. The overall material production cost is reduced, and the impact of raw material price fluctuations on the gross profit margin of manufacturers is weakened. In terms of performance and economy, it surpasses the high nickel ternary.

03 Who is mass-producing four yuan?

On the track for mass production of quaternary lithium batteries, only LG New Energy and Honeycomb Energy are running on them for the time being.

LG New Energy, formerly the battery division of LG Chem, announced its independence in December 2020. On June 8, LG New Energy launched an IPO. It is expected to go public in the third quarter of this year, with a valuation of 100 trillion won (approximately 573.3 billion yuan), which is expected to set the record for the largest IPO in South Korea.

At the same time, LG New Energy also announced that it will provide a quaternary lithium battery for the domestic Model Y in July this year, which is expected to increase the cruising range of the Model Y from 500km to 650km, alleviating the public’s “mileage anxiety”.

In addition to supplying Tesla, in March 2020, LG announced that it will jointly launch a new battery product Ultium with General Motors of the United States, which also uses high-nickel quaternary NCMA materials. It is expected to be mass-produced in 2022 and equipped with GM's Hummer electric car.

Domestically, Honeycomb Energy also has plans for mass production of quaternary lithium batteries.

Honeycomb was originally a power battery division of Great Wall Motors. It started battery research and development in 2012 and became independent in 2018. It has now completed a round of 3.5 billion yuan financing with a valuation of 26 billion yuan. According to general manager Yang Hongxin, Honeycomb is preparing a B round of financing of 3 to 5 billion yuan and is expected to be listed on the Science and Technology Innovation Board in 2022.

Compared with LG New Energy, a battery veteran, the recruit hive is not inferior. On July 9, 2019, Honeycomb brought quaternary materials, cobalt-free batteries, and high-efficiency cell stacking technology at its first press conference. In the second half of this year, quaternary batteries are expected to achieve mass production.

However, Honeycomb’s quaternary battery is not the same as LG’s. Honeycomb chose the medium nickel route. The nickel content is 75%, the manganese content is increased to 25%, and the energy density is 265Wh/kg. The performance is similar to that of NCM811, but the heat Better stability, cycle life up to 3000 times.

At present, Honeycomb has invested 48.5 billion yuan in the layout of battery production capacity, a total of 110GWh, and the construction of 24GWh in Saarland, Germany, is expected to exceed 200GWh in 2025.

Then focus on the upstream of the quaternary cathode material, the precursor industry. Domestic companies such as GEM, Huayou Cobalt, and Zhongwei already have the technology for mass production of NCMA precursors.

It is worth mentioning that Ningde Times is among the mainstream customers of GEM. In response to investors’ questions, the company’s board secretary said: “The NCMA quaternary precursor materials developed by the company are already undergoing customer ton-level certification.”

Therefore, some people in the industry believe that the Ningde era may be engaged in the research and development of NCMA batteries, but the Ningde era may also directly bypass the quaternary materials and go straight to solid-state batteries. After all, the company has already published patents for sulfide solid electrolytes and is expected to start introducing solid-state electrolytes in 2025. For batteries, the energy density of the cells will be greater than 400Wh/kg.

But at present, mass production of solid-state batteries is still a long way off. Xiong Baiqing, chairman of the Guolian Automobile Power Battery Research Institute, once said: "All-solid-state batteries are still far from commercialization. It is very difficult to overcome all-solid-state batteries in 10 years. Anyway, this No show for 5 years."

As a transitional product between ternary and solid-state batteries, solid-state batteries have a more competitive advantage than ternary under the background of the difficulty of commercial mass production. It is expected to circle its own share in the power battery world dominated by iron-lithium and ternary dual heroes.