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The gel electrolyte significantly influences gel valve-regulated lead acid battery performance. To address this, the paper describes the preparation of novel polymer gel electrolytes using poly (vinyl alcohol) (PVA) and tetraethylorthosilicate (TEOS) for valve-regulated lead–acid batteries. FTIR technique is used to confirm the chemical reaction between PVA and TEOS. Electrochemical analyses such as cyclic voltammetry and electrochemical impedance spectroscopy were applied to optimize the concentration of PVA-TEOS polymer gel electrolyte. The optimum concentration of polymer gel electrolyte was determined as 20 wt% of TEOS in PVA (PE-1) with higher anodic peak and lower Rs and Rct values. The Galvanostatic charge–discharge tests were performed on the optimized gel system prototype battery. The highest capacity of 6.86 × 10−5 Ah at a current density of 0.2 mA cm−2 was achieved with an excellent capacity retention ratio of 85.7% over 500 cycles. The exceptional cycle performance and high capacity make PVA-TEOS gel electrolyte a promising candidate for practical battery application.

Tetraethylorthosilicate (TEOS)-crosslinked poly(vinyl alcohol) (PVA) solution was prepared and treated with benzaldehyde 2 sulphonic sodium salt acid (B2SA) for sulfonation. Different contents of graphene were incorporated into B2SA-grafted PVA–TEOS hybrid membrane to improve the membrane stability, mechanical strength, and overall pervaporation performance of the membranes. Membranes were fabricated using the casting technique. Developed membranes were then analyzed for their physicochemical changes by means of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), contact angle analysis (CA), and mechanical strength. The lower d-spacing value observed in WAXD was evidence for the decreased inter-chain distance between the polymer chains. DSC exhibited the enhanced thermal stability of the developed membranes compared to the plane PVA membrane with enhancement in Tg value (106 °C), which was well above the pervaporation experimental temperature. Incorporation of graphene induced higher mechanical strength to the fabricated membranes. Further, the membranes were tested for the pervaporation separation of bioethanol. All the membranes were stable throughout the pervaporation studies, with M-2 G showing the total permeation flux of 11.66 × 10−2 kg/(m2 h) at 30 °C.

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Nanobacterial cellulose (NBC) was produced and incorporated into biodegradable poly(vinyl alcohol) (PVA) in different weight ratios to obtain polymer nanocomposite membranes. The physicochemical properties of the membranes were studied using Fourier transform infrared (FTIR) spectroscopy, a universal testing machine (UTM), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD) techniques, and field emission scanning electron microscopy (FESEM). FTIR confirmed the consolidation of NBC into PVA by exhibiting significant changes in the peaks compared to NBC and PVA individually. The highest tensile strength of 53.33 MPa and 235.30% elongation at break of the membrane M-10 mass % NBC was obtained, illuminating that NBC provides stiffness and PVA imparts elasticity. WAXD revealed that the crystalline nature of the membrane increases up to 10 mass % and decreases beyond it. The effect of NBC on the poly(vinyl alcohol) membranes for food packaging was investigated systematically. Among all the membranes, M-10 mass % NBC was found to be the most suitable for packaging applications. Membranes had antimicrobial activity against food microbes and showed degradability behavior in the soil. The tests on membranes for packaging revealed that fruits were protected from spoilage caused by microorganisms. Hence, the prepared membranes could be used as an alternative to conventional plastics for packaging applications.