Development of a New Generation High-Energy Lithium Metal Polymer Battery

In the race for the electrification of transportation, many companies are competing to develop more efficient solid-state batteries for commercial applications. Since the landmark discovery of using polyethylene oxide (PEO) as a lithium-ion carrier for lithium metal batteries by Armand in 1978, solid-state batteries based on polymer electrolytes have been deeply scrutinized;¹ Viable commercial applications have been provided by Blue Solutions since 2011.² Despite their many advantages, such as the ability to use lithium metal as a negative electrode as well as reduced cell weight and enhanced overall safety, the use of polymer electrolytes remains limited. Additionally, the low overall ionic conductivity and transport number (t+), poor high-voltage stability, and elevated operating temperature remain obstacles for their wide implementation in electric vehicles (EVs).<br/><br/>In this presentation, we outline our efforts to develop a high-energy and long-life cycle NMC – Polymer Electrolyte - Li metal pouch cell. Major challenges are addressed in this pursuit, including stability of polymers with NMC, stable interface between all components, preventing dendrite growth, and developing a scalable process.<br/><br/>Using a star-shaped polymer as electrolyte, we developed a specific formulation to accommodate high C-rate cycling. This polymer is easily scalable for the industrialisation and requires only a negligible amount of solvent to be processable. Considering the need to minimise the process cost and diminish the ecological footprint, this feature provides meaningful advantages for the commercialisation.^3-4<br/><br/>Another major achievement was the development of new Organic Ionic Plastic Crystal (OIPC), which was implemented as catholyte in the electrode formulation. Our new formulation allows the continuous production of cathode electrode using conventional coating machines used in Li-ion battery industry. Based on the unique properties of the new OIPC family, we achieved high C-rate with a good capacity retention more than 500 cycles at C/6 – 1 C.⁵<br/><br/>This technology was successfully scaled up at the format of 1 Ah pouch cell, and will be further scaled up to large format cells &gt; 20Ah using our in-house pilot line in 2023.<br/><br/>References<br/><br/><br/>1. Mauger, A.; Julien, C. M.; Goodenough, J. B.; Zaghib, K., Tribute to Michel Armand: from Rocking Chair – Li-ion to Solid-State Lithium Batteries. Journal of The Electrochemical Society 2020, 167 (7), 070507.<br/>2. Xu, L.; Lu, Y.; Zhao, C.-Z.; Yuan, H.; Zhu, G.-L.; Hou, L.-P.; Zhang, Q.; Huang, J.-Q., Toward the Scale-Up of Solid-State Lithium Metal Batteries: The Gaps between Lab-Level Cells and Practical Large-Format Batteries. Advanced Energy Materials 2021, 11 (4), 2002360.<br/>3. Zaghib, K.; Dontigny, M.; Gauthier, M.; Charest, P.; Michot, C.; Guerfi, A.; Jalbert, J. Process for purifying an electrolyte, the electrolyte thus obtained and its uses. CA2517248, 2007.<br/>4. Macher, S.; Schott, M.; Dontigny, M.; Guerfi, A.; Zaghib, K.; Posset, U.; Loebmann, P., Large-Area Electrochromic Devices on Flexible Polymer Substrates with High Optical Contrast and Enhanced Cycling Stability. Adv. Mater. Technol. (Weinheim, Ger.) 2021, 6 (2), 2000836.<br/>5. Daigle, J.-C.; Barray, F.; Guerfi, A.; Fleutot, B.; Garitte, E.; Krachkovskiy, S.; Koh, K. S. Ionic plastic crystals, compositions comprising same, methods for manufacturing same and uses thereof. WO2022165598, 2022.