Cost and Safety — NMC 5–/6-Series Might Make a Comeback This Year

Author: CBEA
Source: http://www.cbea.com/djgc/202101/007037.html
Translation/edit: MoneyballR

In the game of costs, safety and range, LFP and nickel rich technology have received a lot of attention in corresponding markets and segments, and were frequently the focus of discussions in the industry last year. It looked like medium nickel content ternaries lost popularity, but that is not the case. Medium nickel content ternaries are appearing in another form — monocrystalline medium nickel content ternary.

Looking at battery OEMs, 2020 saw CATL, Sunwoda, REPT, IPNETECH launch medium nickel content monocrystalline ternary batteries. As far as materials go, monocrystalline 5-/6-series have become key products for Easpring, GEM, CNGR, Cylico, Zhenhua, Ronbay, XTC and other cathode producers. Worth mentioning is that Tesla also registered a patent for monocrystalline NCA electrode with over 4K cycles and lifetime range of 1.6M km.

Battery OEMs as well as EV startups also launched nickel medium content ternary products, which might help nickel medium content batteries’ to rally a counterattack.

Better safety, better cost, better lifecycle — monocrystalline nickel medium quietly rises

Increasing battery density has always been major direction in the evolution of battery technology. In the past few years, under the guidance of subsidy policies, battery energy density was increasing year by year. Materials went from LFP in the beginning to ternaries, and ternaries went from NMC111 to NMC523, 622 and to the current 811 and even higher. Nickel content gradually increased and energy density with it. This has always been mainstream development direction among ternary cathodes.

But then problems occurred as with higher nickel, higher cell energy density and decreased cobalt, battery’s safety risks dramatically increased too. Despite having NMC811 battery installed on a massive scale in the past two years, industry generally thinks that safety features and cost of NMC811 products need to go through further reiteration and improvement, and that companies that do not have enough experience with the product should be very cautious about its application.

With current material and technology roadmaps, increasing nickel content is not the only method to increase cell density. Increasing cathode voltage is also one of the options. Compared to polycristalline, monocrystalline materials are more suitable to make voltage higher. At the same time, monocrystalline material interior does not have grain boundaries, which increases cycle stability of ternary materials and it comes as a pleasant surprise for extending battery’s cycle life.

Also, medium nickel content ternary due to its lower nickel content and high cobalt content, compared to nickel rich counterpart, offers safety assurance. In addition, monocrystalline material heat output, stability and safety features are by far better than nickel rich materials.

When it comes to preparation costs, currently monocrystalline medium nickel content production technology is more complex compared to polycrystalline, material price is also relatively high. But if you compare the costs, it still has an advantage compared to nickel rich preparation costs.

In reality, when nickel, cobalt and manganese ratios are equal, monocrystalline ternary gram capacity is slightly lower compared to polycrystalline ternary, but as its voltage is higher, material’s total energy density is similar to the current nickel rich ternary.

Energy density is close, safety and cycle performance is better and the cost is lower. These factors are also behind medium nickel content monocrystalline ternary market share increase. Industry data shows, among ternary shipments in the Chinese market, over 50% were monocrsytalline ternary materials.

Currently, market mainstream in monocrystalline ternaries are Ni-5 and Ni-6 series, while Ni-3 and nickel rich ternary share can be ignored.

Many companies are quietly launching monocrystalline medium nickel content products

In November 2020, domestic EV startup NIO launched 100 kWh battery pack. Reportedly, the pack has no heat spread, or as CATL advertised it — only smoke, no fire battery. It is worth noticing that this battery’s cells are CATL Ni-55 ternary cells.

Of course, this was certainly not the first time CATL showed its monocrystalline 5-series battery product. In July 2020, SAIC Roewe ER 6 installed NMC523 cell. Its cell energy density is 243 Wh/kg. In August Geely Geometry C installed high voltage NMC523 cell. We can assume that CATL has been offering monocrystalline nickel 5-series to OEMs since the beginning of 2020.

In November 2020, Sunwoda presented its “inflammable” ternary battery pack. From what we learned, the battery pack has cells with cathodes that use 5-series monocrystalline high-voltage ternary material — Ni-5X cathode. As Sunwoda revealed, by using monocrystalline high-voltage Ni-5X series material, thermogenesis is 18% lower compared to other systems. Thermal stability (thermal runaway temperature) is 30% higher compared to the other systems. As for energy density, since monocrystalline material voltage is higher, by increasing monocrystalline material voltage, Ni-5X energy density gets near to those in nickel rich systems.

At the same time in November last year, new battery player, Lead Power, presented its first product, which is also based on high-voltage medium nickel content — Ni-6-series. According to company’s introduction, they chose high voltage medium nickel content for two reasons — energy density which can reach nickel rich level via high voltage and medium nickel content, as well as safety due to which medium nickel content has an advantage over nickel rich system.

Last year, REPT launched its high voltage 4.35V, Ni55+graphite system product. Cells in corresponding products have 245 Wh/kg energy density and have started to be installed in batches. Based on REPT presentation, monocrystalline Ni-5 series is near NMC811 energy density, but when it comes to cycle life, safety and cost, it has a clear advantage over NMC811.

Last year in April, Tesla registered a monocrystalline NCA electrode patent. Patent documents show that batteries using the technology can charge 4K times during lifetime, while the lifetime range is over 1.6M km.

Beside monocrystalline ternary, in 2020, Fengchao launched cobalt free battery, Xingheng revealed super-lithium S7 which also adopted monocrystalline technology. Monocrystalline technology received equal application in various systems.

General advantages of monocrystalline medium nickel content in safety, energy density, cost, cycle life have rather early caught downstream attention and R&D efforts. Recently, GEM revealed that it mainly produces nickel rich and monocrystalline high-end products and that it currently has 130Kt/year capacity for these products. Easpring said its monocrystalline, high-voltage 6-series products received overseas and domestic client recognition. Ronbay said that it has always been focused on nickel rich and monocrystalline ternary cathode materials as main R&D direction. The company has commercialized monocrystalline NMC523, monocrystalline NMC622, while monocrystalline NMC811 and high energy density NCA commercialization is underway.

As monocrystalline medium nickel content quietly becomes popular, we can see a phenomenon in which many companies are returning to NMC523 system.

High safety, energy density, cycle life and low cost is what EV OEMs look in battery, but it is also a trend in battery tech development. Currently popular LFP, medium nickel content ternary and nickel rich ternary battery tech roadmap can solve one or several issues, but none of them can solve all. This is the main reason why different battery technologies perform different in different usage scenarios.

Currently, monocrystalline medium nickel content ternary performance balances relatively well between cost, safety, high energy density, life cycle demands. Currently, CATL, Sunwoda, REPT and other battery OEMs already started mass introduction and production. We estimate that high voltage monocrystalline Ni5 and Ni6 medium nickel content system will become one of major technical roadmaps for more companies in the future, which will drive up the share of medium nickel content ternary.

Of course, big players launching monocrystalline medium nickel content does not mean that introduction of nickel rich products will now slow down. Increasing energy density is still a major direction in the industry. In 2020, CATL, LG Chem, Panasonic, SKI, Samsung SDI, Tesla and other international giants have either started nickel rich (mainly NMC811) mass production or have announced production start schedule for nickel rich and ultra nickel rich batteries. In a ternary race, increasing nickel share is still a major direction and if we assume that the pursuit of longer range will continue, the trend of increasing nickel content will not be disrupted short term. The crucial question is how to make a safe and economically feasible battery. I believe that this is the field where most of battery OEMs will compete in the future.