A new kind of single Li-ion polyelectrolyte based on triazolate in a polyurea matrix: syntheses and properties

In this work, a new class of single Li-ion polyelectrolyte (SLIP) based on a polyurea matrix was developed from triazolate salt and diisocyanates with an aliphatic or aromatic moiety. The structure and chemical information were checked by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses. The aggregate structure, thermal stability, phase behavior and morphology were examined via X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy, respectively. It was found that the obtained SLIPs were disordered pore materials with amorphous structures and high stability, and the influence of varied isocyanate monomers on their properties was associated with hydrogen bonding derived from urea linkage. Furthermore, the electrochemical properties for the SLIPs absorbing dimethyl sulfoxide were determined by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy, and the results showed that the electrolytes could endure an oxidation potential up to 4.2 V (vs. Li+/Li) and exhibited a practicable conductivity (10−4 S cm−1) at 30 °C. The cycling performance for an Li|Li cell was also tested preliminarily. The obtained results indicated that the developed SLIPs could be used as potential polyelectrolytes in lithium batteries.