The Oekobat‑2020 project investigated environmentally friendly lithium‑ion battery chemistries and manufacturing routes that could match the high energy density of conventional NCM cathodes while reducing material costs and ecological impact. The research focused on blends of high‑energy NCM 111 with LiFePO₄ (LFP) and on the use of lithium‑manganese‑iron‑phosphate (LMFP) supplied by Johnson Matthey. A water‑based binder system was employed, and the addition of LiH₂PO₄ lowered the cathode paste pH to 7.4, suppressing aluminium collector corrosion. The cathode blends contained 85 % NCM 111 and 15 % LFP, and the resulting electrodes were produced on a 10‑liter pilot plant (FPL) with a ceramic separator from Freudenberg that required additional drying steps because of its hygroscopicity.

Electrodes of the first generation (Gen 0) were compared with those of a second generation (Gen 1) that incorporated a refined particle‑size distribution and improved coating protocols. In 1.5 Ah pouch cells, Gen 1 electrodes exhibited a 40 % lower internal resistance at 20 °C and 0 °C, and a 30 % reduction at 40 °C and –10 °C, compared with Gen 0. The capacity retention after 500 cycles was 86 % for Gen 1 versus 83 % for Gen 0, indicating a modest improvement in cycle life. However, Gen 1 cells lost capacity more rapidly during calendar ageing at 60 °C and 80 % state of charge, suggesting a temperature‑dependent manganese dissolution typical of spinel cathodes. In high‑rate testing, Gen 1 pouch cells achieved a 10 % higher capacity and energy density at low C‑rates and more than a 200 % increase at 3 C, demonstrating the benefit of the blended chemistry for fast‑charge applications.

Full‑cell tests were performed in two formats. First, flat‑wound PHEV‑1 cells were assembled from Gen 1 electrodes and a Freudenberg ceramic separator. The cells reached a capacity of 23 Ah and an energy content of 80 Wh in the third cycle. Second, 1.5 Ah stacked pouch cells were fabricated on the FPL. CT analysis revealed internal winding defects that were corrected in subsequent batches, yet Gen 1 pouch cells maintained superior performance across the entire C‑rate range. The pilot plant scale-up involved a winding machine, a spray nozzle for electrode coating, and a digital multimeter with data logger, all of which were purchased with project funds.

The project employed 40 personnel, including students, technicians, engineers, and scientists, and produced one master’s thesis and two internships. Funding was provided through a grant (Zuwendung) that covered personnel costs, consumables, travel for project meetings and conferences, and capital equipment. Collaboration was extensive: Johnson Matthey supplied the active materials, SGL Carbon provided three generations of graphite, Freudenberg delivered ceramic separators, and Varta Microbattery and Varta Storage received electrodes and cells for further testing and for exploring second‑use stationary storage concepts. The partnership structure enabled the transfer of recipes and manufacturing knowledge between the research institute and industry partners, ensuring that the developed materials and processes could be scaled to near‑industrial levels. The Oekobat‑2020 project thus delivered a set of high‑energy, environmentally benign cathode blends and demonstrated their viability in practical cell formats, while establishing a collaborative framework for future technology transfer.