Metal and Metal-Oxide-Based Polymeric Nanodielectrics for Energy Storage: Opportunities and Challenges

In recent times, with devices becoming smaller, cheaper, and faster, it has become a dire need to provide devices that can store an abundant amount of energyEnergy, which gets delivered also nearly instantaneously. Such devices are not only for finding applicationsApplications in complex military and medical needs but also for commercial day-to-day applicationsApplications too. Metal-oxide-based traditional capacitors do have high dielectricDielectrics constant, but they inherit low breakdown field strength resulting in low energy densityEnergy density and poor mechanical properties to be cast as high energy storageEnergy storage capacitors. Contrary to these, the polymeric materials, which are lightweight and easily amenable to be cast in various sizes and shapes and are cost-effective for mass production, possess relatively high breakdown strengthsBreakdown strength but very low values of dielectricDielectrics constant and poor high-temperature performance become unfit for be manufactured as high energy storageEnergy storage devices. Polymer nanodielectricsPolymer nanodielectrics are a new class of materials that combine the processability, breakdown field strength, and low-loss features of polymersPolymer with the high dielectricDielectrics constant of metal oxideMetal Oxide fillersFiller. This chapter examines this class of materials, first shedding light on their current level of development, including those created for both low-temperature and high-temperature applicationsApplications. A meticulous summary of underlying theories and concepts that construe the correlation between physical property and the energy storageEnergy storage capability of materials has been presented. The contrast in electric behaviors of metallic nanofillers and the host polymerPolymer tends to provide real challenges in achieving viable high energy storageEnergy storage materials. The last part of the review addresses mitigating such challenges and how and what future research should focus on.