2022 ANNUAL REPORT

49 Abstract Topic 5 Lithium-Sulfur Batteries Lithium-sulfur (Li|S) batteries with metallic lithium as the negative electrodes and elemental sulfur as the positive electrodes’ active mass are electrochemical systems with the potential for extremely high gravimetric energy density. Sulfur is abundant, cost-effective, and batteries is constrained by several problems, including shuttle side reactions that lead to inevitable loss of active materials. We showed that the formation of effective solid electrolyte interphase (SEI) on the surface of sulfur/microporous carbon composite electrodes during the initial discharge in fluoroethylene carbonate-based electrolyte solutions makes it possible the operation of S/carbon composite electrodes via the quasi-solid state (QSS) mechanism. The development of advanced Li|S batteries with practical parameters is in progress in our lab. Abstract Topic 6 All Solid State Batteries Solid-state batteries have received renewed attention in recent years due to the growing demand for high energy density rechargeable batteries. The highest energy density of Li and Na batteries can be reached if thin foils of the active metals can serve as the anodes. Solid state electrolytes may be much more compatible with Li and Na metal anodes than conventional liquid electrolyte solutions. This is a major driving force for developing solid state batteries. There are continuous efforts to increase the possible energy density of rechargeable Li and Na batteries, while maintaining high efficiency, and best safety features. Our group work with: - Active and non-active ceramic filers, different salt type, various ceramic filers shape such as: sphere, nanotubes, and nanowires. Salt-free systems. Surface treatment. - Symmetric cell with blocking and non-blocking electrodes, as well as full cells. -Impedance process analysis: monitoring the cells performance (i.e.: bulk conductivity and SEI formation) with time and compering cells performance in static (aging) conditions vs. dynamic (cycling) conditions. - Compering interface of inorganic electrolytes particles in polymer and inorganic electrolytes pellets with polymer membrane. - Spectroscopic analysis: NMR, XPS. Abstract Topic 7 Supercapacitors Supercapacitors are the devices defined by higher power densities than batteries and higher energy densities than conventional dielectric capacitors Activated carbons are abundantly used for supercapacitor applications from several decades. This is particularly due to its abundance in earth’s crust, highly conductive nature and being ecofriendly material. Further unique stability of carbons in various electrolyte solutions under wide range of potentials and temperature emboss their candidature for supercapacitors. These carbon matrixes can be fine-tuned for their porosity and surface areas in very much tailor-made fashion. The activation process can provide high surface areas ranging from several hundred to more than 2000 m2/g. These properties are critical for high specific capacity of ion adsoption and also determines high-rate of diffusion in and out of pores of electrodes during chargedischarge processes. Composite materials which are combinations of carbon core and other components like nanomaterials, oxides/ nitrides of metals are being experimented in order to enhance energy density of these capacitors without affecting power density and cycle life. For instance, carbon nanotubes and graphene which are extensively studied also as core active material, gives advantage of large surface area and high conductivity, however, it fails to produce high volumetric capacitance along with agglomeration, tedious fabrications and is very much cost exorbitant. By combination of such unique materials with conventional low-cost materials can serve in best possible way for maximum output in supercapacitors. In recent years our group is heavily involved in studying the systems in which sole materials suffer from a limitation that can be overcome by its hybrid format with other components like nanomaterials, oxides, nitrides, MXene, and organic moieties like quinones. Following Ragone plot is the gist about the scope of our work on supercapacitors. Abstract Topic 8 Lead-Acid Batteries Lead-acid batteries are invented by the French physicist Raymond Gaston Plante in 1859, these batteries are made up of a spirally wounded pair of lead electrodes. Later sticky paste technology was developed on lead sheets, lead-alloy grids and commercialized successfully in the global community. The major failures in lead-acid batteries are irreversible sulfation, positive active material shedding, oxidative grid corrosion, low utilization of active material, and low specific energy. In the scientific community, research has been devoted to improving the energy density with lightweight substrates and the inclusion of suitable electrolyte and electrode additives with reduced cost. Our group actively working on carbon nanotube (CNT)-based additives for advanced leadacid batteries for commercial applications. Physical integration of CNT-based additives into a positive and negative paste to

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