UCLA

With climate change upon us, the development of energy storage technologies to increase the integration of renewable energy systems is critical. Thus, a variety of energy storage systems are required to meet the wide array of demands from grid-level storage to high-power, fast-charging electric vehicles. This dissertation presents the introduction of novel Li- and Na-ion chemistries and materials systems for energy storage (Chapter 3 and 5) and demonstrates further development of full-cell chemistries for industrial applications (Chapter 4). In Chapter 3, we present a method for high-power electrode development from high ionic conductivity solid-state electrolytes in a model Na-ion system: Na-β alumina (NBA). The substitution of a redox active ion, Fe, for Al within the NBA structure enabled development of a high-power Na-ion battery electrode with 75% capacity retention at a 20C-rate. This work demonstrates a new avenue for materials research development in high-power materials design and improved interface compatibility of electrodes with solid state electrolytes. In Chapter 4, we present high-power Li-ion devices, which can deliver charge in a matter of minutes instead of hours, that could transform the electric vehicle market as well as consumer electronics and ‘internet-of-things’ (IOT) devices. The Nb2O5-based devices demonstrate the advantage of pseudocapacitive materials, those with capacitor-like kinetics, in full-cell battery systems. Energy storage devices with the demonstrated power-density capabilities are necessary to realize the clean energy goals of the upcoming decades and mark a significant step from lab-scale to practical applications. Finally, in Chapter 5, a combination of high-power and high-energy is demonstrated in amorphous sulfides: a-WSx and a-TaSy. This is the first demonstration to date of high-power, amorphous materials for energy storage with evidence of multielectron, anionic redox. The development of amorphous sulfide materials highlights the advantage of amorphous over crystalline structures for multielectron, anionic redox reversibility as well as the importance of local atomic ordering compared with long-range order for fast charging capabilities. Taken together, the work presented here delivers pathways for future materials development and design in Na- and Li-ion battery systems from fundamental materials properties for high energy and high power to full-cell, prototype devices.