Studies on the ions transportation behavior of alginate doped with H+ carrier-based polymer electrolytes

In the present work, amorphous bio-based polymer electrolytes (BBPEs) using alginate polymer as a matrix host and doped with varying amounts of ammonium iodide (NH4I) have been developed via the solution casting technique. The physicochemical properties of alginate-NH4I BBPEs were evaluated by using X-Ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), electrical impedance spectroscopy (EIS), and transference number measurement (TNM). The BBPEs film containing 25 wt % of NH4I possessed the highest ionic conductivity of 1.29 × 10−4 S cm−1, the highest amorphous phase, and good thermal stability of up to 234 °C. Based on the Nyquist fitting approaches, the ionic conductivity of the BBPEs was primarily influenced by the ion transportation, which was due to the interplay of segmental motion between the alginate and NH4I, and also the H+ hopping mechanism, as shown by FTIR. The proton transference number (tH+ = 0.41) suggests that alginate BBPEs are promising materials in electrochemical device applications

Characterization of an amorphous materials hybrid polymer electrolyte based on a LiNO3-doped, CMC-PVA blend for application in an electrical double layer capacitor

In the present work, hybrid polymer electrolytes consisting of a CMC-PVA blend doped with various amounts of LiNO3 was produced using the casting technique. The structural and ionic conductivity of the prepared samples were studied by using Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical impedance spectroscopy (EIS) analyses. The optimum ionic conductivity at room temperature was achieved at 3.54 × 10−3 S cm−1 with the addition of 20 wt % of LiNO3 which showed the lowest percentage of crystallinity. IR-deconvolution revealed that the ionic conductivity is dependent on the ionic mobility and diffusion coefficient. Linear sweep voltammetry was performed where the highest ionic conducting sample is electrochemically stable up to 1.43 V. The highest conducting sample was fabricated into an electrical double layer capacitor (EDLC) and was characterized by using cyclic voltammetry and galvanostatic charge-discharge (GCD) for their electrochemical stability performance. The GCD profile showed that the fabricated EDLC is stable to operate up to the 5000th cycles with the average specific capacitance of ~100 F/g

Investigation on favourable ionic conduction based on CMC-K carrageenan proton conducting hybrid solid bio-polymer electrolytes for applications in EDLC

In the present work, a proton-conducting hybrid solid biopolymer electrolytes (HSBEs) system was successfully prepared via the solution casting approached. The HSBEs comprised of CMC blended with kappa carrageenan and doped with NH4NO3. The HSBEs system was characterized to evaluate the structural and the proton conduction properties using FTIR, XRD and EIS techniques. The FTIR analysis showed that a complexation occurred between the CMC-KC and H+ moiety of the NH4NO3 via the –OH, C–O–C as well as –COO- groups with associated changes observed to their wavenumbers and peak intensities. At the 80:20 ratio of the CMC:KC hybrid system, the optimum value of the ionic conductivity was found to be ~10−7 S/cm. However, the addition of 30 wt % of NH4NO3 to the system markedly increased the ionic conductivity to ~10−4 S/cm due to the increase in the amorphous phase in the HSBEs system as revealed by the XRD analysis. Meanwhile, the IR-deconvolution approach revealed an increase of the protonation (H+) from NH4NO3 towards the co-ordinating site on the hybrid CMC-KC system and this in turn, led to the increment in the ionic mobility and diffusion of ions for transportation. An EDLC was fabricated using the highest conducting HSBEs sample developed in the present study and it exhibited favourable characteristics as a capacitor with a reasonably good stability with regards to its electrochemical properties