(606c) Single-Ion Conducting Crosslinked Polymer Composite Gel Electrolytes

Electrochemical energy storage devices are increasingly desired for the electrification of transportation and utilization of renewably generated power. Safety and performance of batteries is strongly dictated by the performance of the electrolyte. Polymer electrolytes offer advantages over liquid and inorganic solid-state electrolytes, as they can be non-leakable and non-volatile, yet flexible. Single-ion conducting electrolytes that eliminate ion concentration gradients can offer further advantages: greater electrochemical stability allowing for higher voltage cells, lower interfacial impedance, and higher theoretical charge/discharge rates. Unfortunately, the relatively low ionic conductivity of single-ion conducting polymer electrolytes has hampered their use thus far.

This talk will highlight our recent efforts to understand ion transport in single-ion conducting crosslinked polymer gel composite electrolytes. Crosslinked, single-ion conducting lithium polymer composite electrolytes are created by polymerizing difunctional macromonomers and ionic monomers when mixed with lithium conducting glass ceramic particles. Various chemistries of polymer chains (macromonomers) are used, and the material properties of the composite gel electrolytes are investigated after swelling the networks in various solvents. It is found via Raman spectroscopy that the presence of the ceramic particles strongly influences the association state of the tethered anions within the crosslinked network. The ceramic particles also strongly influence the mechanical properties and the ionic conductivity of the polymer gel electrolytes. A significant enhancement in ionic conductivity is observed for certain polymer-solvent-particle combinations. The complexity of the polymer-solvent-anion-particle interactions in affecting ionic conductivity of the composite gels will be discussed.