The “polymer syntheses” target the preparation of multifunctional block copolymers as polymer electrolytes and active materials.
New synthetic routes for ABA-type block copolymers with soft and hard blocks are were developed. These systems were evaluated as solid polymer electrolytes (SPEs) with varying compositions of conducting salts, showing good conductivity without sacrificing mechanical properties. Further, multiblock copolymers and mixtures of functional polymers were synthesized, the obtain 3D-nanostructured materials allowed an intimate contact between the redox active polymers and electrically conducting agents or nanostructured SPEs with faster Li-ion transport. Moreover, an electric field responsive liquid crystalline block could be oriented resulting in significantly enhanced ionic conductivity.
Beyond block copolymers, conjugated microporous polymers were synthesized and applied both in conventional and novel Na, Mg, and Al batteries.
The “material characterisation” enabled insights into the structure-property relationships of polymer electrolytes and polymer active materials, e.g. by highly advanced techniques x-ray and electron microscopy with nanometer resolution to elucidate morphology, non-equilibrium structures, and the bulk phase diagram.
Microscopic and scattering characterization methodologies for SPEs based on block copolymers were developed to provide valuable insights for controlling synthesis parameters and benchmarking SPE properties. The findings offer an accurate characterization, emphasizing techniques to study the near-native state and to identify promising polymer materials.
The “energy storage technology” targets the integration of the most promising materials in advanced post-LiBs and all-solid LiB prototypes, such as Na, K, Mg, Ca, Al, hybrid organic batteries, and pRFBs. An assessment of organic electrode materials was implemented, highlighting their potential as low-cost, sustainable, and air-stable energy storage solutions towards real-world applications. Detailed simulations on e.g. cost analysis and experimental validation derived a clear path toward sustainable, low-cost post-LiB technologies.
Additionally, guidelines of future organic polymers were provided to focus on particle size reduction, addition of fillers or structural modifications that facilitate multivalent ion-mobility. At the same time, the limitations in state-of-the-art multivalent electrolytes were identified, mainly redox stability and desolvation of multivalent salts.
Work on SPEs for solid state LiBs revealed the interplay between EO chains and Li salts, and effect of ionic liquid on ion mobility and transport properties. Importantly, the SPEs demonstrated promising performance with high voltage cathodes, highlighting their potential for next-generation lithium metal batteries.
With regard to organic RFBs, a life cycle assessment was compiled including the techno-economics.
The project contributed to the development of safer, more efficient battery systems, pushing the boundaries of current Li batteries and towards the next-generation safe and high density energy storage. The results were disseminated in peer-reviewed publications in high-impact journals and at international conferences.
