(130g) Tailoring Ion Solvation Environment in Porous Polymer Electrolytes

Single-ion conducting solid electrolytes are often presented as a potential solution to the challenges facing commercial battery electrolytes; however, current single-ion conducting ceramics and polymers cannot adequately address the necessary safety and performance criteria. The shortcomings of these conventional materials motivate the design of novel materials that are capable of addressing these requirements. Porous aromatic frameworks (PAFs) are a recently developed class of materials that demonstrate promise as single-ion conducting electrolytes. In particular, the modular nature of these porous frameworks permits precise control over the local cation environment and allows for tuning of bulk electrochemical properties. This work presents the synthesis and electrochemical characterization of a new anionic porous aromatic framework and elucidates the solvation environment of cations within this framework using a variety of nuclear magnetic resonance methods. In this work, ⁷Li, ¹H, and ¹⁹F solid-state NMR spectra provide a picture of the local cation environment; relaxation measurements and pulsed-field gradient NMR provide insight into local cation dynamics and permit the calculation of bulk diffusion coefficients. NMR results are compared with electrochemical impedance data to correlate solvation environment with ionic conductivity. The relationships between framework design, solvation structure, and electrochemical properties will aid the design of future PAFs with improved properties for battery applications.