Korea-based SK Innovation said it will start the first commercial production of mid-and large-size pouch-type NCM-811 batteries. NCM-811 refers to the nickel-rich layered cathode material, comprising 80% nickel, 10% cobalt and 10% manganese. SK Innovation has been producing NCM-622 cells (60% nickel, 20% cobalt, 20% manganese in the cathode). SK Innovation said that the new higher energy density cells could extend EV range by another 100 km compared to current cells.
In a 2016 review paper published in ACS Energy Letters (Myung et al.), a team of Korean researchers suggested that the vast majority of electric vehicles on the market over the next decade will use nickel-rich cathode materials—LiNi1−x−yCoxAlyO2 (NCA) and LiNi1−x−yCoxMnyO2 (NCM) in particular. Extending intrinsic capacity in these layered oxides requires, for example, increasing nickel content. Such an effort, however, also involves balancing other operational parameters (power, lifetime, safety, cost).
|An overview of NCM compositions from Argonne National Laboratory and BASF. Click to enlarge.|
… using NCA and NCM cathodes to fill the gap between the present generation of automotive batteries and the 2025 target requires fine-tuning of the available variables of nickel content, upper cutoff voltage, packing density, and loading level. In parallel, the development of efficient modification techniques must offer even better mitigation of the degradation processes that unavoidably will become harsher as the cathode energy density is increased.
… Apart from possible co-doping, the results presented in this Review clearly indicate that no Ni-rich cathode material will be able to meet the energy density, power, lifetime, and safety targets unless one or more stabilization techniques are adopted.
… Surface stabilization is mandatory to diminish the reactivity and reduce the amount of highly reactive Ni4+ and/or impede the reactivity toward the electrolyte. The simultaneous adoption of a compositional gradient, with a Mn-rich shell region, and a surface coating appear at the moment as the most promising technical solution. Further improvements could include further refining of the gradient profile to further optimize the trade-off between energy density and cycle stability. Coatings deposited with more sophisticated deposition techniques, like atomic layer deposition, could also prove beneficial due to superior uniformity and potential for much better thickness control. Promising results on this topic have been recently reported for both NCA and NCM 811 cathodes. Nevertheless, the impacts of these kinds of deposition techniques on the final material cost remain to be fully evaluated.—Myung et al.
SK Innovation said that the new NCM-811 cells would be used in stationary energy storage systems starting in December of this year, with targeted deployment in electric vehicles beginning in the third quarter of 2018.
The batteries will help extend a driving range of electric vehicles up to 500 km, and we will also develop new batteries by 2020 that can provide a range of more than 700 km.—Lee Jon-ha, SK battery R&D center
In August, SK Innovation reorganized to put the battery unit and R&D lab under the direct supervision of CEO Kim Jun.
SK Innovation said it plans to boost its battery production to 10 GWh by 2020 and secure 30% of global market share for electric vehicle batteries by 2025. SK Innovation currently supplies batteries to Mercedes-Benz, Kia Motors and China’s BAIC Motor Corp.
Seung-Taek Myung, Filippo Maglia, Kang-Joon Park, Chong Seung Yoon, Peter Lamp, Sung-Jin Kim, and Yang-Kook Sun (2016) “Nickel-Rich Layered Cathode Materials for Automotive Lithium-Ion Batteries: Achievements and Perspectives” ACS Energy Letters 2 (1), 196-223 doi: 10.1021/acsenergylett.6b00594