Solid polymer electrolyte based on waterborne polyurethane for all-solid-state lithium ion batteries

A series of solid polymer electrolytes (SPEs) based on comb-like nonionic waterborne polyurethane (NWPU) and LiClO4 are fabricated via a solvent free process. The NWPU-based SPEs have sufficient mechanical strength which is beneficial to their dimensional stability. Differential scanning calorimetry analysis indicates that the phase separation occurs by the addition of the lithium salt. Scanning electron microscopy and X-ray diffraction analyses illustrate the good compatibility between LiClO4 and NWPU. Fourier transform infrared study reveals the complicated interactions among lithium ions with the amide, carbonyl and ether groups in such SPEs. AC impedance spectroscopy shows the conductivity of the SPEs exhibiting a linear Arrhenius relationship with temperature. The ionic conductivity of the SPE with the mass content of 15% LiClO4 (SPE15) can reach 5.44 x 10(-6) Scm(-1) at 40 degrees C and 2.35 x10(-3) Scm(-1) at 140 degrees C. The SPE15 possesses a wide electrochemical stability window of 0-5 V (vs. Li+/Li) and thermal stability at 140 degrees C. The excellent properties of this new NWPU-based SPE are a promising solid electrolyte candidate for all-solid-state lithium ion batteries. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45554.