Production Research as Key Factor for Successful Establishment of Battery Production on the Example of Large-Scale Automotive Cells Containing Nickel-Rich LiNi0.8Mn0.1Co0.1O2 Electrodes

The increased focus on electromobility in European countries is closely linked to the establishment of local lithium-ion battery (LIB) mass production facilities, such as Tesla's Gigafactory 1 in Nevada. While extensive knowledge in LIB lab-scale assembly already exists, the transfer to industry-scale production is an area of challenge that is tackled through intense production research. Slurries of nickel-rich NMC811 that is sensitive to environmental conditions, and therefore more difficult to process, are successfully up-scaled to 65 kg industry-scale batches and investigated through rheological measurements. Defect-free, double-side-coated electrodes with approximate to 400 m in length are obtained via slot-die coating and assembled into large-scale PHEV-1 cells with graphite as the counter electrode. Possible production-induced defects are examined through computed tomography (CT). The obtained qualified, automotive cells are investigated through galvanostatic charge/discharge testing that confirms excellent cycling performance with discharge capacities of 26.3 Ah (1st cycle) and 25.4 Ah (300th cycle), which corresponds to a capacity retention of 96.6%. These results are compared with NMC811-containing cells from lab-scale/literature, and large-scale products (slurries, electrodes, and PHEV-1 cells) containing the predecessor material NMC622. The scalability of slurry preparation, electrode production, and cell assembly with special emphasis on differences between lab-scale and industry-scale production is discussed.