Plasma enables smaller, more powerful NMC-811 cathodes

Batteries could shrink even more with smaller crystals in the cathodes. Battery packs in electric vehicles and consumer goods could become smaller, while still offering high performance.

September 17, 2020 Marian Willuhn

thousands of tons of cobalt exist already in the U.S. in the form of unused electronics.

Image: Rob Nunn

U.S.-headquartered plasma technology company 6K claims to have made a battery material advancement with its new NMC-811 cathode, which is just 1-3 microns wide.

More precisely, the company says it can use its plasma technology to melt a single crystal NMC-811 particle. The cathode material stands for nickel manganese cobalt, with nickel content eight times that of manganese and cobalt. NMC-811 cathodes are low in cobalt and hence cheaper, while still delivering high power and energy density.

“We are responding directly to strong demand we’ve had from multiple iconic brand customers in the EV and consumer battery markets who are seeking higher nickel content and smaller size NMC,” said Richard Holman, VP of Battery Products for 6K. “In less than three months our team was able to adapt the NMC-622 process to produce NMC-811 at over 200 mAh/g, and dial in sizes from 1-3 microns. What is a challenge for standard co-precipitation is relatively easy for 6K Energy, which underscores the power of the UniMelt production process.”

Its previous NMC-622 cathode was reportedly tested by an independent validation laboratory. The test showed a reversible capacity close to 180 mAh/g and a first cycle efficiency rate of 92%. At the time, the manufacturer said the results were consistent with the performance gains expected by its customers.

The UniMelt process is developed by 6K. The company name stands for 6,000 K, which is roughly the temperature at which microwave plasma exhibits different reactions, including the formation of NMC crystals. The industry reportedly prefers NMC crystals, as they could help battery manufacturers to improve charge times, ramp up power, and extend battery capacities. Moreover, 6K claims that its process of producing NMC crystals allows for the omission of multiple materials and energy-intensive steps, compared to conventional methods.

“Our NMC 811 development is just the tip of the iceberg, both in terms of what is possible for battery chemistries, but also the positive impact on our business model and market realization,” said Aaron Bent, CEO of 6K. “We innovate in days and weeks, not months and years. We have an intelligent closed-loop, almost combinatorial approach to product design. What’s more, the same platform used to innovate at grams per hour is used in scaled production for 100 tons per year with our UniMelt platform, collapsing the time to market entry. UniMelt technology allows us to build an ecosystem/partner model that completely changes the development paradigm allowing our customers to hone in on chemistries that enhance their cell performance they simply can not obtain with other technologies.”

Plasma-created cathodes are not entirely new in the battery materials market. In the past, 6K has used its UniMelt process to create LTO, NMC-333, NMC-532, NMC-622, and silicon anodes featuring nano-structured foam and intermetallic composite powers.

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