DEVELOPMENT OF FLEXIBLE TRIBOELECTRIC NANOGENERATORS AND SOLID-STATE LITHIUM-ION POLYMER BATTERIES FOR ENERGY CONVERSION AND STORAGE PURPOSES

Conventional techniques to harvest and store energy are challenged by the ever-increasing demand for versatile forms of electrical energy caused by the rapid expansion of the Internet of Things (IoTs). As emergent solutions, flexible triboelectric nanogenerators (TENGs) and lithium-ion batteries (LIBs) have been invented and extensively studied in recent years. Different TENGs are fabricated to scavenge mechanical energy from most natural sources and human motions, making them portable solutions to energy generation on-demand. On the other hand, rechargeable LIBs play critical roles in the evolution of energy over 50 years, owing to its abilities to store massive amount of energy, lay the foundation for portable smart devices, and make possible a fossil fuel-free world. At the beginning of this dissertation, latest efforts that incorporating low-dimension carbon materials with TENG systems will be systematically reviewed. Carbon materials, including graphene and carbon nanotube, can bring many synergistic properties to TENGs, such as output enhancement and multifunctionality. They are poised to further the reach of TENG applications and make a positive impact on common issues related to TENG technology. The second section is to present a robust route to fabricate flexible TENGs with multifunctionality by nano-patterning thermoplastic polyurethane (TPU) thin films. Topographically optimized TENGs could promote higher power generation while preventing biofilm formation without using any chemical additives. Analysis of pattern amplitude and wavelength correlation to output power is uniquely provided for a deeper understanding of how patterned TENGs enable peak performance. The last part of this work presents the fabrication and characterization of lithium-ion batteries based on solid-state polymer electrolytes. Efforts made to substitute conventional liquid electrolyte and plastic separators make a great accomplishment on mechanical properties and safety aspects of LIBs. Fluoroethylene carbonate (FEC) has been proved as an effective electrolyte additive, which helps building LIB systems with ultra-high capacity and low self-discharge. Comprehensive electrochemical properties along with thermal properties of LIBs will be closely scrutinized in this work.