DEVELOPMENT OF VITRIMERS FOR SOLID STATE POLYMER ELECTROLYTES
Swetha Karingal Veedu, Alvaro Quinteros Sedano, Evelyne van Ruymbeke, Jean-François Gohy, Charles-André Fustin
UCLouvain, Institute of Condensed Matter and Nanoscience (IMCN), Bio and Soft Matter division (BSMA), Place Louis Pasteur 1, Louvain-la-Neuve 1348, Belgium
Solid polymer electrolytes (SPEs) are promising for high energy density Li-metal batteries (LMBs), offering safety advantages over traditional liquid electrolytes, which pose leakage, flammability, and stability issues.1 Chemically crosslinked SPE enhance mechanical strength and thermal stability but lack reprocessability and self-healing capabilities. Vitrimer-based SPEs have emerged as a potential alternative to address these limitations. Vitrimers are a new class of crosslinked polymers that possess the ability to flow at high temperatures due to the presence of exchangeable covalent bonds.2 This feature allows for reprocessability, recyclability, improved adhesion, and better ionic conductivity—key attributes for next-generation SPEs.1,3
The objective of this project is to investigate the effective implementation of the vitrimer behavior to improve various properties of solid polymer electrolytes. This will be pursued through the synthesis of vitrimer-like SPE networks, in which properties are tuned by changing both the nature of the dynamic covalent bonds (DCBs) and the topology of the networks. The findings are expected to facilitate the development of the next generation of solid polymer electrolytes for sustainable solid-state LMBs with enhanced quality, reliability, and lifetime.
Here, we present two network topologies based on Poly(ethylene glycol) methacrylate (PEGMA) and two types of boronic ester as DCBs. The first network is made by reacting two polymers bearing complementary boronic ester functions. The second network is directly obtained by photopolymerization with a difunctional dioxaborolane crosslinker and dioxazaborocane comonomer. The resulting networks are further studied to evaluate their dynamic and electrochemical properties through rheology and ionic conductivity tests.
[1] Gu, W.; Li, F.; Liu, T.; Gong, S.; Gao, Q.; Li, J.; Fang, Z. Recyclable, Self-Healing Solid Polymer Electrolytes by Soy Protein-Based Dynamic Network. Adv. Science 2022, 9(11), e2103623. doi:10.1002/advs.202103623
[2] Van Zee, N. J.; & Nicolaÿ, R. Vitrimers: Permanently crosslinked polymers with dynamic network topology. Progress in Polymer Science 2020, 104. doi:10.1016/j.progpolymsci.2020.101233
[3] Hayashi, M. Implantation of Recyclability and Healability into Cross-Linked Commercial Polymers by Applying the Vitrimer Concept. Polymers 2020, 12(6). doi:10.3390/polym12061322