In recent decades, the enhancement of the properties of electrolytes and electrodes resulted in the development of efficient electrochemical energy storage devices. We herein reported the impact of the different polymer electrolytes in terms of physicochemical, thermal, electrical, and mechanical properties of lithium-ion batteries (LIBs). Since LIBs use many groups of electrolytes, such as liquid electrolytes, quasi-solid electrolytes, and solid electrolytes, the efficiency of the full device relies on the type of electrolyte used. A good electrolyte is the one that, when used in Li-ion batteries, exhibits high Li+ diffusion between electrodes, the lowest resistance during cycling at the interfaces, a high capacity of retention, a very good cycle-life, high thermal stability, high specific capacitance, and high energy density. The impact of various polymer electrolytes and their components has been reported in this work, which helps to understand their effect on battery performance. Although, single-electrolyte material cannot be sufficient to fulfill the requirements of a good LIB. This review is aimed to lead toward an appropriate choice of polymer electrolyte for LIBs.

The primary goal of the current study is to improve the specific capacitance of electric double-layer (EDLC) device using biomass (Tribulus Terrestris) derived activated carbon electrodes synthesized by chemical activation method. Furthermore, high surface area carbon electrodes are characterized using X-ray diffraction (XRD), RAMAN spectroscopy, and scanning electron microscopy (SEM) to confirm the morphological structure. Finally, the electrochemical performance of fabricated EDLC proves a good agreement data using Cyclic Voltammetry (CV), Low Impedance Spectroscopy (LIS), and Galvanostatic Charge–Discharge (GCD) analysis showing the high specific capacitance of 115 Fg⁻¹ for the optimized 1:2 activated carbon material.

Activated porous carbon was synthesized from methylcellulose biopolymer through a two-step mechanism involving H₃PO₄ as an activating agent and then thermally carbonized in a tubular furnace under an inert atmosphere at 850 °C. The product was next rinsed with strong HCl, neutralized with deionized water, and dried in an oven at 80 °C. Then, to fully understand the behavior of the activated porous carbon, it was characterized using techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), RAMAN spectroscopy, Brunauer–Emmett–Teller (BET), and thermal gravimetric analysis (TGA). Additionally, we have created dye-sensitive solar cells and an electric double-layer capacitor (EDLC) using this porous carbon produced from methylcellulose (DSSC). We used the above-mentioned prepared porous carbon for the electrode portion of the Electric Double-Layer Capacitor (EDLC) fabrication, and the maximized polymer electrolyte film made from the methyl cellulose (MC) biopolymer combined with 60 wt.% of 1-ethyl-3-methylimidazolium tricyanomethanide ionic liquid (IL), with a maximum conductivity of 1.93 × 10⁻² S/cm, for the electrolyte. The fabricated EDLC device shows a specific capacitance of 60.8 F/gm at 5 mV/s scan rate which was confirmed by cyclovoltammetry and a low-frequency impedance plot in the CH electrochemical workstation. The DSSC device was fabricated using the same porous carbon as a material for the counter-electrode and the same composition polymer electrolyte that had been used in the EDLC as the electrolyte for the DSSC which yields an efficiency of 0.86%. The fill factor and other parameters were also calculated from the JV characteristics that had been characterized and obtained in the solar simulator.