Development of Polyurethane-Based Polymeric Electrolytes Modified with Graphene Oxide for Lithium-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) are among the most important technologies for electrochemical energy storage due to their widespread application in portable electronic devices, stationary energy storage systems, and electric vehicles ​(Lv et al., 2022)​. However, conventional liquid electrolytes present several safety concerns, including flammability, electrolyte leakage, and lithium dendrite formation, which may compromise battery performance and lifespan. In this regard, solid polymer electrolytes (SPEs) have emerged as a promising alternative to enhance the safety and stability of LIB systems ​(Lv et al., 2022; Wang et al., 2020)​.
In this work, SPEs based on waterborne polyurethane (PU) matrices incorporating lithium chloride (LiCl) were developed. The polyurethane was synthesized using methoxy poly(ethylene glycol) diol (MPEG-diol), 1,4-butanediol (1,4-BDO), isophorone diisocyanate (IPDI), graphene oxide (GO), and ethylenediamine (EDA), with dibutyltin dilaurate (DBTDL) as the catalyst. Films containing different LiCl concentrations were prepared to evaluate the influence of lithium salt content on the physicochemical and electrochemical properties of the resulting SPEs.
The resulting materials were characterized by Fourier-transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The results revealed that the formulation containing 10 wt.% LiCl exhibited the highest ionic conductivity, reaching 1.25 × 10^-6 cm^-1. These findings demonstrate the potential of the developed systems as SPEs for lithium-ion battery applications.