Research Projects

Special attention is required on the sustainable energy resources and electric vehicles to overcome the energy deficiency and air pollution, which can be solved by developing energy storage technologies. The energy generated from the renewable energy sources needs to be stored for efficient use as and when required. The energy can be stored using various devices, such as dielectric, electrochemical capacitors, and batteries. However, electrochemical capacitors and batteries have various disadvantages, such as slow charging/discharging speed, low operation voltage, and low power density as compared to dielectric capacitors. The dielectric capacitors have low cost, high operating voltage, high power density, high temperature stability and fast charge-discharge time (100’s ns), making them a suitable candidate for energy storage utilized for advanced pulsed power technology. Among the available dielectric categories, relaxor ferroelectric (RFE) materials are the best-suited candidate for energy storage systems due to their large dielectric permittivity and high saturation polarization, low remnant polarization, excellent temperature stability, diffuse phase transition, and slim P-E loop behavior. Among the studied relaxor-based ferroelectric materials, Bi-based layer-structured perovskite material having the chemical composition of BaBi₄Ti₄O₁₅ (BBT) has excellent potential for energy storage due to its large energy density and efficiency, high thermal stability over a wide frequency range, anisotropy in electromechanical coupling, low leakage current, high operating voltage, and high fatigue endurance. In the past, the energy storage performance of the BaBi₄Ti₄O₁₅ has been tuned by various methods, which have limitations such as solubility, uncontrolled defect formation, selectivity, etc. These problems can be overcome by creating the defects in a controlled manner using the ion beam techniques by controlling the energy and fluence of the incoming ion. The advantage of ion beams is that they can create defects beyond the thermodynamic limit. The produced defects will reduce the domain wall or domain pinning energy, remnant polarization, delay in low field saturation, enhance the breakdown field, and fatigue endurance, resulting in an increased energy density. The objective of this study is to develop the BaBi₄Ti₄O₁₅-based dielectric ceramic capacitor for energy storage with high energy density (> 200 J/cm³), high breakdown field (> 5 MV/cm), large fatigue endurance (> 10¹⁰ cycles), high efficiency (> 90 %) and wide temperature stability (up to 200°C). Thin film samples will be prepared using the pulse laser deposition and RF-sputtering technique on (a) platinized silicon wafers, and (b) F-mica substrates. The energy storage properties of BBT ceramics will be enhanced using the ion bombardment techniques. We believe that the performed study potentially enhances the energy density and efficiency of dielectric capacitors for energy storage.