The project, funded by the German Federal Ministry of Education and Research (BMBF) under the competence cluster “ExcellBattMat”, ran from 1 November 2019 to 31 March 2023 and was carried out by the Centre for Solar Energy and Hydrogen Research Baden‑Württemberg (ZSW) in the field of accumulator material research. The report was authored by Dr Peter Axmann and Dr Margret Wohlfahrt‑Mehrens. The main aim was to develop sustainable, cobalt‑free cathode and anode materials for high‑energy lithium‑ion batteries, avoiding critical raw materials such as cobalt, nickel and graphite, and to scale promising materials to kilogram quantities for roll‑to‑roll (R2R) electrode production.

In the anode domain, silicon was incorporated into graphite particles by a novel rounding process that produced carbon/silicon composites with a controlled spherical or spheroidal particle design. The resulting composites showed a 70 % increase in specific capacity compared with pure graphite, while the initial coulombic efficiency remained comparable to that of graphite. Volumetric capacity was significantly enhanced, and X‑ray diffraction, Raman spectroscopy and BET surface area measurements confirmed that the graphite and silicon components were not adversely affected by the rounding. The material behaved like silicon‑free rounded graphite from a processing perspective, indicating good drop‑in compatibility for existing electrode manufacturing lines. Further work is required to improve cycle stability, but the study established a clear pathway for integrating silicon into high‑capacity anodes.

For cathodes, several material families were investigated. Protective surface coatings on lithium‑nickel‑manganese‑oxide (LMNO) particles were developed using boron and a “y” component. The boron coating doubled the stability of the LMNO base material, and the combined crystal design and “y” modification increased stability by more than a factor of six. Full‑cell tests against graphite anodes achieved over 650 cycles before reaching end‑of‑life criteria, all using a standard electrolyte without stabilizing additives. Surface chemistry of the modified electrodes was elucidated by X‑ray photoelectron spectroscopy, and single‑particle electrochemical measurements were performed in collaboration with the University of Ulm, the Helmholtz Institute Ulm (HIU) and the German Aerospace Center (DLR).

Lithium‑rich high‑voltage spinels of the composition Li₁₊ₓMn₀.₅Ni₀.₅O₂ were synthesized as spherical precursors and thermally converted. These materials delivered capacities of 200 mAh g⁻¹. Correlative transmission electron microscopy and Raman microscopy revealed phase separation driven by lithium excess at the particle level, providing a model understanding of challenges in Li‑Mn‑rich layer oxides. Scaling of the lithium‑rich spinel to 50 g batches and integration into R2R electrode coating processes were successfully demonstrated, showing the feasibility of producing kilogram‑scale cathode material with controlled microstructure.

Mn‑rich lithium layer oxides were also advanced. Spherical NaₓNi₀.₃₃Mn₀.₆₆O₂ precursors were produced at several hundred‑gram scale, and lithiation to the final product was carried out at the HIU. This work established a scalable route for new cobalt‑free, high‑energy cathodes.

Collaboration was extensive. The University of Ulm contributed expertise in particle architecture and single‑particle electrochemistry; the HIU provided advanced characterization and lithiation facilities; the DLR supplied kinetic studies and modeling; and the Helmholtz Institute for Environmental Research (HIU) and the Institute for Materials Research (IMR) contributed to surface chemistry and coating development. The project’s outcomes provide a solid knowledge base for the industrial implementation of sustainable, high‑energy lithium‑ion battery materials.