ABSTRACT
The focus of the study in this article is analyzing the electrochemical properties of molybdenum disulfide on miscible poly(methyl methacrylate)-poly(lactic acid) blends for supercapacitors. The interaction between molybdenum disulfide and miscible poly(methyl methacrylate)-poly(lactic acid) blends, affinity toward water, surface morphology, and mechanical properties are inspected by Fourier transform infrared spectroscopy, water contact angle, scanning electron microscopy, and universal testing machine, respectively. Among the developed membranes, 0.75 wt% of molybdenum disulfide on poly(methyl methacrylate)-poly(lactic acid) shows better electrochemical performances. It exhibits a maximum specific capacitance of 255.5 F g-1 at a current density of 1.00 mA g-1, maximum energy density of 22.7 Wh kg-1, and maximum power density of 360 W kg-1. A cycle study reveals 92% capacitance retention after 2500 cycles. The designed supercapacitor device shows a maximum specific capacitance of 1240 µF g-1 at a current density of 0.5 µA g-1, maximum energy density of 43 µWh kg-1, and maximum power density of 700 µW kg-1. Flexible membranes of molybdenum disulfide are expected to be a potent combination for supercapacitor applications.
ABSTRACT
The electrochemical act of valve-regulated lead acid batteries can be enhanced by conductive materials like metal oxides. This work aims to examine the preparation and influence of zirconia on poly(vinyl alcohol) based gel valve-regulated lead acid battery. Characterizations like Fourier transform infrared spectroscopy, ionic conductivity, water retention study, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge techniques were done. The optimized gel system exhibited a discharge capacity of 198.45 µAh cm-2 at the current density of 0.6 mA cm-2. The battery cell with an optimized gel matrix displayed a maximum discharge capacity of 22.5 µAh at a current of 20 µA. After 500 continuous cycles, the battery attained a discharge capacity retention of 91 %. The presence of zirconia will increase the electrochemical performance of gel valve-regulated lead acid batteries.
ABSTRACT
In this study, the impact of graphene-doped poly(vinyl alcohol) hydrogels on gel-valve-regulated lead acid batteries was examined. The gel formulations were made by adding various amounts of graphene into the gel system comprising poly(vinyl alcohol) and sulfuric acid. Gel formulations were subjected to an ionic conductivity study and Fourier transform infrared spectroscopy (FTIR) to understand ionic mobility and material interaction, respectively. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) were utilized to find the optimized amount of graphene in gel formulations. Galvanostatic charge-discharge (GCD) techniques were employed on a battery comprising an optimized gel electrolyte. The battery exhibited a discharge capacity of 12.82 mAh at a current density of 15 mA cm-2. After 500 prolonged cycles, the battery displayed a discharge capacity of 87% at 25 mA cm-2 current density, indicating that graphene-doped hydrogels can be a promising gel electrolyte for lead acid batteries.
ABSTRACT
In the past few years, significant research efforts have been directed toward improving the electrochemical capabilities of supercapacitors by advancing electrode materials. The present work signifies the development of poly(lactic acid)/alloysite nano-clay as an electrode material for supercapacitors. Physico-chemical characterizations were analyzed by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, and a universal testing machine. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge techniques were employed to evaluate electrochemical characteristics. The optimized poly(lactic acid)/halloysite nano-clay film revealed the highest specific capacitance of 205.5 F g-1 at 0.05 A g-1 current density and showed 14.6 Wh kg-1 energy density at 72 W kg-1 power density. Capacitance retention of 98.48% was achieved after 1000 cycles. The microsupercapacitor device presented a specific capacitance of 197.7 mF g-1 at a current density of 0.45 mA g-1 with 10.8 mWh kg-1 energy density at 549 mW kg-1 power density.
ABSTRACT
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.
