Book Description

Wearable electronics and sensors are being extensively developed for several applications such as health monitors, watches, wristbands, eyeglasses, socks and smart clothing. Energy storage devices such as rechargeable batteries make wearable devices to become more independent from power outlets, or in other words, make device portability. Battery energy density determines how long a battery powered device will work before it needs a recharge. Longer the time before battery needs recharge, better it is for device applications. Therefore, the goal of battery researchers and engineers is to develop a battery that can provide high energy density and longer device operation. The state-of-the-art battery is the lithium-ion battery (LIB) technology outperforming any other battery for the aforementioned applications. Even LIB is limited in energy storage (energy density ~200 Wh/kg) and requires frequent battery charge. Some other major challenges associated with LIBs are high cost, low cycle life (restricted to 500 - 1000 cycles), safety, and negative environmental impacts. Further improvement in LIB is very limited as the technology is reaching the theoretical limit and therefore new battery technology with greater energy density and overall better performance must be developed in order to match the ever increasing power demand in fast growing electronics. Lithium sulfur battery (LSB) (energy density ~2600 Wh/kg) is one of the most promising batteries for next generation energy storage, enabling approximately 10 times more energy storage in LSB than LIB. Furthermore, sulfur is inexpensive, abundant and environmental friendly. Therefore, LSB is expected to be more economical, safe and environmentally sustainable compared to LIB. However, performance (cycle life, thermal stability and safety) of current LSB technology do not meet commercialization standards at current development stage and thus, open for further technological advancements. My thesis focuses on the development of novel materials that when successfully developed will improve the overall performance of LSB and can meet commercialization standards by combining thermal and dendrite-proof solid ion conducting ceramic based electrolyte (no liquid spillage) along with solid state and flexible S-cathode being developed in the Electrochemical Energy Systems Laboratory at the University of Dayton Research Institute (UDRI) of University of Dayton (UD).