A Promising Polymer Blend Electrolytes Based on Chitosan: Methyl Cellulose for EDLC Application with High Specific Capacitance and Energy Density

Abstract

In the present work, promising proton conducting solid polymer blend electrolytes (SPBEs) composed of chitosan (CS) and methylcellulose (MC) were prepared for electrochemical double-layer capacitor (EDLC) application with a high specific capacitance and energy density. The change in intensity and the broad nature of the XRD pattern of doped samples compared to pure CS:MC system evidencedthe amorphous character of the electrolyte samples. The morphology of the samples in FESEM images supported the amorphous behavior of the solid electrolyte films. The results of impedance and Bode plotindicate that the bulk resistance decreasedwith increasing salt concentration. The highest DC conductivity was found to be 2.81 × 10−3 S/cm. The electrical equivalent circuit (EEC) model was conducted for selected samples to explain the complete picture of the electrical properties.The performance of EDLC cells was examined at room temperature by electrochemical techniques, such as impedance spectroscopy, cyclic voltammetry (CV) and constant current charge–discharge techniques. It was found that the studied samples exhibit a very good performance as electrolyte for EDLC applications. Ions were found to be the dominant charge carriers in the polymer electrolyte. The ion transference number (tion) was found to be 0.84 while 0.16 for electron transference number (tel). Through investigation of linear sweep voltammetry (LSV), the CS:MC:NH4SCN system was found to be electrochemically stable up to 1.8 V. The CV plot revealed no redox peak, indicating the occurrence of charge double-layer at the surface of activated carbon electrodes. Specific capacitance (Cspe) for the fabricated EDLC was calculated using CV plot and charge–discharge analyses. It was found to be 66.3 F g−1 and 69.9 F g−1 (at thefirst cycle), respectively. Equivalent series resistance (Resr) of the EDLC was also identified, ranging from 50.0 to 150.0 Ω. Finally, energy density (Ed) was stabilized to anaverage of 8.63 Wh kg−1 from the 10th cycle to the 100th cycle. The first cycle obtained power density (Pd) of 1666.6 W kg−1 and then itdropped to 747.0 W kg−1 at the 50th cycle and continued to drop to 555.5 W kg−1 as the EDLC completed 100 cycles.

Structural, Morphological, Electrical and Electrochemical Properties of PVA: CS-Based Proton-Conducting Polymer Blend Electrolytes

“…The Nyquist plot for the chosen PEs can be deduced with regard to the electrical equivalent circuit (EEC), comprising bulk resistance (Rb) for the species charge carriers in the PE films as well as two constant phase elements (CPEs) as revealed in the inserts in Figure 6. The high-frequency area The electrical equivalent circuit (EEC) method is typically employed for examining EIS because the method is straightforward and rapid, as well as conveying a whole image of the PE system [3]. The Nyquist plot for the chosen PEs can be deduced with regard to the electrical equivalent circuit (EEC), comprising bulk resistance (R b ) for the species charge carriers in the PE films as well as two constant phase elements (CPEs) as revealed in the inserts in Figure 6.…”

“…The term CPE is more commonly used in EEC instead of ideal capacitor in the real system. The impedance of Z CPE can be written as follows [3]:…”

“…New materials that follow green chemistry principles have been focused upon extensively due to the lower release of pollutants into the environment [1]. Two strong alternatives, namely batteries and supercapacitors as energy storage devices, appear to replace other non-sustainable energy sources, such as oil, nuclear fuel and other fossil fuels [2][3][4]. Solid polymer electrolytes (SPEs) have been extensively studied to examine their application to large-scale production, within capacitor systems [5].…”

NaClO4 added, corn and arrowroot starch based economical, high conducting electrolyte membranes for flexible energy devices

“…The estimated values of WR are tabulated in Table 3. With increasing salt concentration WR is decreasing which may be attributed to increasing flexibility of starch based systems with increasing salt concentration [11] and hence better contact between electrode and electrolyte. The WR resistance is smaller for CS-xE in comparison to AS-xE for all values of x.…”

Preparation and Characterization of Biopolymer Electrolyte Membranes Based on LiClO4-Complexed Methyl Cellulose as Lithium-ion Battery Separator

“…If it is correlated to the decrease of the crystallinity index, the LiClO4-complexed MC has more pores than pure MC, facilitating ion migration. The existence of more pores and a rougher surface improves the ionic conductivity caused by the increase of amorphous regions [71]. The bulky size of the ClO4anion of salt is responsible for creating sparse Li-ion diffusion, thus exhibiting high ionic conductivity.…”