Plasticized Ionic Liquid Crystal Elastomer Emulsion Based Polymer Electrolyte for Lithium-Ion Batteries

Development and electrochemical characteristics of ionic liquid crystal elastomers (iLCEs) are described for use as electrolyte components in lithium-ion batteries. The unique combination of elastic and liquid crystal properties in iLCEs grants them robust mechanical attributes and structural ordering. Specifically, the macroscopic alignment of phase-segregated, ordered nanostructures in iLCEs serves as ion pathways, which can be solidified through photopolymerization to create ion-conductive solid-state polymer lithium batteries (SSPLBs) with high ionic conductivity (1.76 × 10-3 S cm-1 at 30 °C), and high (0.61) transference number. Additionally, the rubbery state ensures good interfacial contact with electrodes that inhibits lithium dendrite formation. Furthermore, in contrast to liquid electrolytes, the iLCE is shrinking on heating thus preventing any overheating related explosion. The fabricated Li/LiFePO4 (LFP) cells using iLCE-based solid electrolytes show excellent cycling stability with a discharge capacity of ∼124 mAh g-1 with coulombic efficiency close to 100%. These results are promising for practical application of iLCE-based SSPLBs.