Optimisation of dielectric size to increase energy density in triboelectric nanogenerators

Triboelectric nanogenerators (TENGs) have attracted great interest in recent years as innovative devices with the potential to convert mechanical energy into electrical energy. TENGs, which offer the opportunity to obtain energy by utilising natural resources such as human movement, wind or wave motion, are particularly promising for sustainable energy solutions. Although significant success has been achieved in small-scale applications, the development of large-scale TENGs and achieving higher power generation capacities is still a problem to be solved. Several factors that can affect the performance of large-scale TENGs, including the size and configuration of dielectric materials, are being investigated to overcome this challenge. The aim of this study is to optimise the dimensional parameters of dielectric materials such as thickness, surface area and multi-cell TENG configurations to increase the electrical power density harvested in large-scale TENGs. In the study, glass fibre was used as the positive dielectric and multipurpose white silicon was used as the negative dielectric due to its high tribo-potential, durability and easy accessibility. In the size optimisation stage, TENGs with dielectrics of different thickness and surface areas were fabricated and their energy harvesting capacities were examined in detail. The dielectric thicknesses and surface areas required to obtain the maximum power density were determined. Then, horizontal and vertical multi-cell TENG configurations are investigated for efficient integration of size-optimised dielectrics. In this context, horizontal and vertical multicell TENG structures are designed and their power generation performances are compared. Experimental results show that vertical multicell configurations can significantly improve energy efficiency with surface area and thickness optimisations. In particular, vertical multi-cell configurations reveal that a high and sustainable energy density can be achieved for electronic devices. This thesis study highlights the importance of size and configuration optimisation to increase the power generation capacities of TENGs and contributes to the development of more sustainable solutions in power generation by providing an important reference for future large-scale TENG designs. Keywords: Triboelectric nanogenerator, high power density, dielectric layer, size optimisation, multi-cell TENG.