Periodic Reporting for period 1 - VERSAPRINT (Versatile printed solutions for a safe and high-performance battery system)
Reporting period: 2023-05-01 to 2024-10-31
• At cell level, improving safety and performances by:
- providing efficient cell thermal regulation by printing micro-channels on the cell surface, allowing to reduce risk of TR and increase density and lifetime (BB1)
- improving the system thermal and safety management, thanks to in operando monitoring of temperature and detection of H2 via printed sensors (BB2)
• At cells unit level, targeting safety, performances and circularity by:
- adding thermal dissipation, electrical shunt and safe dismantling functions on busbars via multi-functional designs (BB3)
- allowing easy and safe dismantling and re-manufacturing of batteries by new busbar designs (BB4)
• At module level, targeting safety, performances and environmental footprint by:
- lowering the casing’s weight, without losing its capability to contain Thermal Runaway (TR) and while ensuring good recycling rate, thanks to the use of Self-Reinforced Polymer (SRP) (BB5)
- providing an advanced fire response through the addition of recyclable Phase Change Material and Flame Retardants (PCM/FR) to polymeric components (BB6)
- controlling the gas/fire released during a TR by cooling and evacuating exhaust gases safely thanks to an exhaust gas management system (BB7).
In addition, VERSAPRINT will implement a Decision Tool to choose the most optimised configuration for a given application (in terms of BBs, of cell chemistry…). The BBs used individually or in combination depending on end-user requirements, will be demonstrated at TRL5 for key applications:
• At module level: prototyping of 2 modules (automotive and aeronautics applications) and virtual prototyping for waterway transport
• At system level: simulation for all above applications.
The design of BB1 has been proposed (CFD simulations and CAD designs), 3D printed onto dummy cells. The micro channels showed no leakage when circulating water. The same process with real cells is ongoing to be tested and assembled into cell units to test the efficiency of BB1. The results at cell level are in D2.5 and will be shown at cell unit level in D3.2.
Temperature sensors (BB2) are being developed with bio-based and recycled contents. A design and a formulation have been proposed, showing good resistivity properties. Work still has to be done due to the unforeseen effect of humidity. Hydrogen sensors (BB2) are also being developed. Their resistance proportionally increases with the increase of concentration of hydrogen, even at low levels. However, the response time is still too slow (20 s), more work is needed to reach the objectives.
In WP3, cell units will be assembled using the CAD from D3.1 to demonstrate the scalability of BB1. The tests on cell units will start in Dec 2024. Innovative busbars were successfully developed. BB3 was designed, 3D printed and tested. It combines heat dissipation, ease of assembly by welding and ease of disassembly using a first and a second life busbar. It contributes to the objectives of an increased safety during operating steps. Two different designs of BB4 "easy-to-dismantle" have been developed. The decrease of time needed for disassembly as has been assessed to >90% compared to welded busbars and the risks of electrisation almost disappears.
In WP4, a generic module was designed. SRP material formulation was developed with PA and PET incorporating FR to reach V0 classification. Their recyclability was studied. The thermoplastic was recovered at >85% and the FR at >50%. Their mechanical properties being too weak, PC was chosen to 3D print the casing. BB7 was designed using simulations of TR, the tests to confirm its efficiency have started and show promising results.
In WP5, the decision tool is designed. It allows the study of 2 cells (LFP and NMC) and will include all the BBs. It implements a multi-criteria decision analysis approach to evaluate and rank different combinations of BBs.
To ensure sustainable lifecycle at module level, few technical developments were assessed using LCA tools. For now, BB1 has a lower environmental impact (decrease of 20%) compared to classic thermal management solutions due to the reduced weight. VERSAPRINTs inks from BB2 have a lower environmental impact than commercial inks (carbon footprint reduction of 40%). The study of BB3, BB4, BB5, BB6 and BB7 will be shown at M21.
BB2: temperature and hydrogen sensors have been formulated using more environmental friendly components. Further research is needed to demonstrate their TRL and start upscaling the process.
BB3: The multifunctional busbar allows to reduce the weight, increase the safety during assembly and disassembly steps. Demonstration at cell unit and module level needs to be done before upscaling the process. Dissemination through publication or protection through patent can be done.
BB4: The "easy to dismantle» busbars were designed and manufactured by 3D printing. They allow to decrease the number of steps and time needed for assembly and disassembly and also decrease the risk of electrisation. Demonstration is needed at cell unit and module level (Jan 2025). Total Cost of Ownership analysis was conducted to evaluate a potential access in markets. Dissemination through publication or protection through patent can be done.
BB5: SRP/PA and SRP/PET materials were processed. Further research has to be conducted to obtain more performant materials.
BB6: SRP/PA+FR and SRP/PET+FR materials were processed and their recyclability studied. Further research has to be conducted to obtain more performant materials.
BB7: The design of the exhaust gas management was 3D printed and demonstration needs to be performed with 1, 3 and 12 cells, to prove its efficiency to avoid TR propagation. Further optimisation will have to be conducted to reduce the weight and volume before accessing markets.
Decision tool: The tool was designed and further research and demonstration have to be done to prove its efficiency to help the end users to choose the appropriate set of BBs for a specific application.