In significant achievements towards LMBs striving toward enabling a higher energy density technology, new generation of dynamically self-assembling/healing electrolytes (TILCs) and piezoelectric separators were developed. The self-healing methods of HIDDEN were analysed also with life cycle assessment (LCA) methods.
The HIDDEN project upscaled the synthesis of the TILC material to a level of hundreds of grams and demonstrated its potential to prevent dendrite growth both by modelling and by experimental results. The related research strategies implemented within symmetric Li°│TILC│ Li° coin cells proved to mitigate the nucleation and growth of Li° dendrites. TILCs allow both preventive and curative self-healing solutions. This is possible through the dynamic control of the Li-ion flow by the self-assembled electrolyte, and at the Li°/TILC interfaces by the application of a temperature-regulated self-healing protocol, respectively. In addition to materials and processing methods, a cell level heating element was developed for controlling the self-healing. The consortium also developed algorithms and protocols to trigger the heating scheme at the required timing.
Piezoelectric separators developed during HIDDEN synergistically provide a complementary preventive solution leveraging their role in mitigating the nucleating and growth of Li° dendrites through regulating the ion flux by a local electric field generated by Li° dendrites, leading to an efficient countermeasure. For the preparation of piezoelectric separator, a Non-solvent Induced Phase Separation (NIPS) process was used, taking advantage of the polymer’s difference in solubility in two different solvents to trigger a phase separation from liquid to solid. Then, PVDF-TrFE was investigated as a potential material to mitigate Li° dendrite growth. In the framework of the HIDDEN project, the process was scaled up to a Roll-to-Roll (R2R) pilot line. Finally, the produced membranes were compared in full battery configurations, demonstrating the potential of piezoelectric polymers in mitigating the capacity fade in lithium metal cells. This demonstration emphasises the promising application of such materials to be used for achieving the goal of the HIDDEN project.
The HIDDEN project successfully created 10 Key Exploitable Results, namely:
1. Library of new Thermotropic Ionic Liquid Crystals (TILCs)
2. Deep learning solution for electrolyte property assessment and design (structure & molecular architecture to properties solver)
3. Piezoelectric separator
4. Characterization and detection of dendrite growth
5. Laser cutting of Li° negative electrode
6. Quality assurance measurement devices within the assembly process
7. Heating element
8. Coating process for the TILC electrolyte & proof-of-concept demonstration of self-healing
9. Optimized assembly process
10. Battery Management System (algorithms, software, hardware)
These results were widely disseminated via online channels (HIDDEN website, social media) as well as in other dissemination means, such as newsletter and scientific publications and conference participations. Partners will exploit the project results in diverse ways: non-commercial exploitation includes using the knowledge in further research, as well as educational activities while commercial exploitation plans concern licensing agreements with industrial players, provision of technology consulting towards industrial players as well as direct use of the technology by the industrial partners.
