The OptiKeraLyt project, funded by the German Ministry of Education and Research (grant 03ETE016H) and carried out at RWTH Aachen University from 1 January 2019 to 30 June 2022, set out to develop industrial processes for battery cells that use ceramic solid‑state electrolytes. The scientific goal was to achieve a gravimetric energy density exceeding 500 Wh kg⁻¹, effectively doubling the theoretical capacity of current lithium‑ion cells, while improving safety compared with conventional LIBs. To reach this target the project combined material, process and manufacturing optimisation. Modified lithium lanthanum zirconate (LLZ) electrolytes were tailored for high ionic conductivity, sinterability and compatibility with mixed‑cathode active materials. Thin‑film deposition and laser sintering were employed for Si anodes and mixed cathodes, and the entire cell assembly was performed in a controlled dry or argon atmosphere to minimise contamination.

A key technical milestone was the development of a robotic assembly line. A collaborative robot in a mini‑environment was adapted to handle the brittle electrolyte. Vacuum suction and Bernoulli grippers were tested; a round flat suction gripper provided the best combination of gentle handling, high adhesion and stable vibration, while the Bernoulli gripper eliminated surface contact entirely. Using these tools the team achieved a cycle time of roughly 2 seconds per monozelle, a significant improvement over manual handling. Parameter optimisation was carried out in a three‑dimensional space of acceleration, speed and trajectory smoothing, allowing the identification of an optimal set that maximised throughput without sacrificing positioning accuracy. Stack tests with polymeric dummies, LLZ pallets and stainless‑steel current collectors confirmed that all components could be lifted and positioned reliably with the chosen grippers, even when the electrolyte surface was porous.

Beyond process development, the project produced a comprehensive cost model and a cell configurator that enabled rapid evaluation of different cell designs. Pairwise comparisons of evaluation criteria were performed for oxide, sulfide and polymer solid‑state batteries, and a hypothetical industrialised cell design was used to illustrate the economic and recycling potential. The modelling framework, which incorporates three‑dimensional micro‑structural resolution, allows early prediction of design trade‑offs and optimisation pathways.

Collaboration was central to the project’s success. The assembly work (AP3B) was carried out in close partnership with Jonas & Redmann, who provided the collaborative robot and expertise in robotic handling. Regular communication was maintained through email, weekly jour‑fixe meetings and workshops for major milestones. The robotic arm used was a FANUC CR‑7iA/L, integrated into a custom cell‑handling platform (CellBot). The project’s interdisciplinary nature required close coordination between material scientists, process engineers and manufacturing specialists, all of whom contributed to the iterative feedback loop that linked material properties, process parameters and final cell performance. The project’s outcomes, including the validated assembly process, the cost model and the recycling assessment, provide a solid foundation for scaling up the production of ceramic solid‑state battery cells and bring the industry closer to the ambitious energy‑density and safety targets outlined by the National Platform for Mobility.