Structural, optical, thermal, and dielectric properties of carboxymethyl cellulose/sodium alginate blend/lithium titanium oxide nanoparticles: Biocomposites for lithium-ion batteries applications

Abstract

Nanocomposites samples of carboxymethyl cellulose (CMC)/sodium alginate (SA) blend (70/30 wt%)-loaded lithium titanium oxide nanoparticles (Li4Ti5O12 NPs) were prepared using the casting method. X-ray diffraction (XRD) spectra showed a decrease of the crystallinity with increasing Li4Ti5O12 concentrations. Fourier-transform infrared (FT-IR) inferred the interaction and complexation between the blend components (CMC/SA), also showed the interaction between Li4Ti5O12 and the functional groups of CMC/SA in particular CHO-CH2 stretching, -COO− stretching, and -OH stretching vibrations. The optical properties of samples enhanced in optical energy gap as the concentration of Li4Ti5O12 increased. The differential scanning calorimetry (DSC) measurement showed that the pure sample has a single glass transition temperature (Tg), which denoted that the blend components were miscible. Also, DSC showed an enhancement in the thermal stability of polymeric blend after the addition of Li4Ti5O12. The highest value of AC conductivity was noticed at the highest concentration of Li4Ti5O12, which was also increased with increasing temperature. The maximum electrical conductivity obtained at 0.40 wt% of Li4Ti5O12 in the polymeric matrix is 9.35 × 10−6 S/cm at room temperature at 107 Hz. The complex permittivity (ε*) was decreased with the increase of both Li4Ti5O12 content and the temperature degree. At high frequencies, the decreasing trend of permittivity was assigned to dipoles orientation. These results indicated that CMC/SA/Li4Ti5O12 nanocomposites would be promising for energy storage capacitors applications and alternative separator rechargeable lithium-ions batteries industries.