Elena Ford1,Scott Black1,Mohit Gupta2,Naba Karan1
University of Connecticut1,Brown University2
Elena Ford1,Scott Black1,Mohit Gupta2,Naba Karan1
University of Connecticut1,Brown University2
Elena Ford 1,5 , Scott Black 1,5, Mohit Gupta 2, Naba K. Karan 3,4,5<br/><br/>1 Dept. Mechanical Engineering, University of Connecticut, Storrs, CT<br/>2 Dept. Mechanical Engineering, Brown University, Providence, RI<br/>3 Institute of Materials Science, University of Connecticut, Storrs, CT<br/>4 Dept. of Materials Science and Engineering, University of Connecticut, Storrs, CT<br/>5 Center for Clean Energy Engineering, University of Connecticut, Storrs, CT<br/><br/>For the past decade, lithium-ion batteries (LIBs) have dominated the electric vehicle sector due to their high energy density and cycle life. Currently, the purpose of LIBs for electric vehicles is to provide and store energy. A structural battery is defined as being multifunctional; it is a load bearing system as well as an electrochemical cell [1]. The electrolyte system is the key enabler for a multifunctional structural battery as it must possess sufficient ionic conductivity (~10<sup>-4</sup>S/cm) and mechanical strength (Youngs’s modulus ~ 2-3 GPa) simultaneously.<br/><br/>In the present work, we study the development of a dual-phase structural battery electrolyte to optimize ionic conductivity and mechanical performance simultaneously. An epoxy resin-based system is chosen due to its high mechanical strength and ability for in situ polymerization. [3] Diglycidyl ether of Bisphenol A (DGEBA) accounts for the epoxy to provide hard segments in the matrix and is cured by an amine compound (Jeffamine T-403). A liquid electrolyte is added to the system for improving the conductivity enhancement without compromising its mechanical strength substantially. Three liquid components consisting of lithium salt and solvents are considered here -lithium bis(trifluoromethanesulfonyl)imide (LITFSI) dissolved in a solution of ethylene carbonate (EC) and dimethyl methyl phosphonate (DMMP), LiTFSI dissolved in Tetraethylene glycol dimethyl ether (Tetraglyme) and LiTFSI dissolved in 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI). Ionic conductivity of the electrolyte systems as a function of temperature is measured utilizing electrochemical impedance spectroscopy. Uniaxial load tests are performed to evaluate the mechanical properties (e.g., Young’s modulus, Yield strength) of the epoxy-based electrolyte systems with and without the addition of the ion conducting liquids. Comparative data on the three epoxy-based systems containing varying amounts of liquid components will be presented.<br/><br/><br/>References<br/>[1]<br/>L. Wehner, N. Mittal, T. Liu and M. Niederberger, "Multifunctional Batteries: Flexible, Transient, and Transparent," <i>American Chemical Society, </i>vol. 7, no. 2, pp. 1-3, 2021.<br/><br/>[2]<br/>L. Froboese, L. Groffmann, F. Monsees, L. Helmers, T. Loellhoeffel and A. Kwade, "Enhancing the Lithium Ion Conductivity of an All Solid-State Electrolyte via Dry and Solvent-Free Scalable Series Production Processes," <i>Electrochemical Society, </i>vol. 167, no. 2, pp. 1-2, 2020.<br/><br/>[3]<br/>Y. H. Song, P. L. Handayani and U. . H. Choi, "The role of inorganic nanoparticle on ion conduction of epoxy-based solid polymer electrolytes for lithium-ion batteries," <i>Molecular Crystals and Liquid Crystals , </i>vol. 687, no. 1, p. 1, 2019.