Manav Rachna University

Zinc-air batteries (ZABs) are becoming a promising technology for high-capacity battery applications such as powering portable electronics, electric cars, and renewable energy systems. ZABs have a lower environmental impact compared to other batteries, are safer compared to LIBs, and are cost-effective since zinc is abundant. However, there were challenges in the initial research on ZABs due to poor chemical reactions on the zinc anode and slow oxygen reaction rates. Despite many benefits, there were challenges in zinc-air batteries. However, there have been significant developments in the fabrication of anodes, development of new electrolytes, and bifunctional oxygen catalysts to improve zinc-air battery performance. Despite these developments, there are challenges in zinc-air batteries, including shorter lifetimes, lower power density, and corrosion of the air electrode. This review article provides an in-depth overview of the fundamental principles, various challenges faced in adopting these principles, and offers suggestions for better battery performance. The article also covers recent developments, applications, and possibilities for electrically rechargeable ZABs, giving an idea of how this promising battery is evolving. This study provides a critical assessment of the progress made in Zn-air batteries The current challenges hindering the development of rechargeable Zn-air batteries are addressed, emphasizing the need for innovative solutions. Various strategies for designing and optimizing Zn-air battery components, including anodes, electrolytes, and oxygen catalysts. Potential research directions are proposed to overcome existing challenges and design practical Zn-air batteries for commercial applications.

The growing global demand for sustainable energy and the environmental limitations of fossil-fuel-based power generation have intensified interest in next-generation photovoltaic technologies. Among emerging approaches, oxide-based solar cells—particularly dye-sensitized solar cells (DSSCs) and perovskite–oxide hybrid systems—have gained considerable attention due to their low fabrication cost, material versatility, and compatibility with flexible or building-integrated photovoltaic applications. Recent studies demonstrate that nanocarbon materials and room temperature ionic liquids (RTILs) can significantly enhance the performance of these devices by improving charge transport, catalytic activity, and interfacial stability. For example, graphene- or ionic liquid-modified electrolytes have been reported to increase ionic conductivity by up to 93

Ternary transition metal oxides (TTMOs) have recently gained attention as promising electrode materials due to their rich redox chemistry, high theoretical capacitance, and synergistic effects among constituent metals. In particular, nanocomposites incorporating ZnO:MnO:VO (ZMV) phases offer enhanced electrochemical performance, structural stability, and ion transport properties. In this study, we report the successful synthesis of ZMV nanocomposites via a controlled hydrothermal route followed by thermal treatment. X-ray diffraction (XRD) analysis revealed that the synthesized material predominantly features the face-centered cubic (FCC) phase of MnO, along with the Wurtzite phase of ZnO and Orthorhombic VO, confirming the multiphase composite structure. Cyclic voltammetry (CV) analysis demonstrated a specific capacitance of 232.11 Fg⁻1. Fabricated devices possess good energy density of 20.6 WhKg−1, excellent power density 800 WKg−1, and superior cyclic stability of 97.2

Recent advances in energy storage devices have earned recognition for the rapid development of sustainable chemistry in the synthesis of metal oxides using plants and their components as reducing agents. In this study, Mentha piperita leaf extract was used as a reducing agent to synthesize zinc oxide (ZnO) for use in supercapacitors along with starch as stabilizing agent. Three powder samples, ZnO (Zn), ZnO reduced with Mentha piperita leaf extract (ZnM), and ZnO reduced with Mentha piperita leaf extract stabilized with starch (ZnMS) were synthesized and systematically characterized. Among the samples, ZnO reduced with Mentha. piperita leaf extract stabilized with starch (ZnMS) exhibited a larger crystallite size according to XRD analysis, and showed a rod-shaped morphology as observed in SEM and FESEM analyses. The presence of oxygen vacancies were confirmed by EDAX, a higher specific surface area from BET analysis, and a reduced optical band gap of 2.99 eV from optical studies. The electrochemical studies for the as prepared materials were made with three-electrode configuration. The electrode made using the powder sample ZnO reduced with Mentha piperita leaf extract stabilized with starch (ZnMS) coated on a graphite sheet exhibited a specific capacitance of 56 F/g at 1 A/g and retained 99

This study presents an optimization of process parameters and output responses of Rotational Arc Gas Metal Arc Welding (RA-GMAW) welded joints of dissimilar aluminium alloys AA6061 and AA7075 using ER4043 filler. Twenty welds were fabricated using a central composite design (CCD) via response surface methodology. The novelty of this study lies in an integrated experimental-statistical framework that employs a CCD and multi-response optimization to quantify how input parameters govern the output responses of the welded joints. The primary input parameters were welding current ranges of 60 to 90 A, arc rotational speed (ARS) ranges of 800 to 1000 rpm, and gas flow rate (GFR) ranges of 14 to 16 l/min, while the responses included ultimate tensile strength, % strain, Vickers microhardness, and compressive residual stress. The experimental results revealed a tensile strength range of 184.63-269.85 MPa, strain values of 7.24%-11.19%, hardness of 85.63-102.41 HV, and compressive residual stress of 2.3-69.7 MPa. Increasing the ARS and adding more heat to the work yielded maximum tensile strengths of about 270 MPa and hardness above 100 HV, while higher currents coarsened grains. The statistical significance of the quadratic regression models was verified by ANOVA, which yielded coefficients of determination (R2) of 0.9835, 0.9465, 0.9653, and 0.9646 for tensile strength, % strain, hardness, and residual stress, respectively. The optimized values of current, ARS, and GFR were 74.1 A, 809 rpm, and 4.49 l/min, and the optimized values of compressive residual stress, hardness, % strain, and tensile strength were 25.31 MPa, 95.10 HV, 10.01%, and 224.04 MPa, respectively. The maximum joint efficiency compared to AA7075 was 56.66%, and compared to AA6061 was 91.26%, demonstrating effective load transfer while highlighting greater strength degradation in the AA7075.