Nanofiller-Based Novel Hybrid Composite Membranes for High-Capacity Lithium-Sulfur Batteries

Abstract

Herein, Al2O3 nanofiller-reinforced lithiated Nafion:Aquivion hybrid composite ion-exchange membranes have been produced by mixing lithiated Nafion and Aquivion ionomers. After the electrochemical tests, the Li-Naf:Li-Aqu/1:2 compound, which offers the best electrochemical performance, was selected. Lithiated hybrid composite membranes were obtained by reinforcing Al2O3 nanofillers at different rates to this composition. The ion exchange capacity, polysulfide transition and solvent uptake of the obtained membranes were investigated and the structural characterizations were applied by tensile test, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and membrane morphology was examined with Field Emission Scanning Electron Microscopy (FESEM). For performing the electrochemical tests, CR2032 half cells were designed. Electrochemical characterizations of the produced membranes were carried out by Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and galvanostatic charge-discharge tests. The best electrochemical performance was achieved with 868 mAhg(-1) discharge capacity and 63.8% capacity retention when Li-Naf:Li-Aqu/1:2 composition was reinforced with 1% Al2O3 nanofiller. As a result, lithiated hybrid composite ion exchange membranes could prevent the shuttle effect of polysulfides while enabling the passing of Li ions for high-performance Li-S batteries.