Supercapacitors are important energy storage devices because they bridge the gap between batteries and electrostatic capacitors. They can be used in stand-alone or battery-assist applications. In this project we develop nanomaterial design and synthesis strategies to improve electrode material performance for supercapacitor applications. We are specifically interested in the development of inorganic layered materials including oxides, chalcogenides, carbides, and phosphides to improve supercapacitor performance.

Microsupercapacitors (integrated electrochemical supercapacitors) for on-chip electrochemical energy storage are fast becoming a critical component of many self-powered and sensor systems. While thin film batteries and micro-batteries have been commercialized, they suffer from limited lifetime and low power density. On the other hand, microsupercapacitors may be a viable replacement for microbatteries due to their very high power density and long cycle life.

he limited resources of Li and its non-uniform geographic distribution makes it essential that alternate mobile ion batteries are developed. Sodium (Na) for example is more abundant and therefore less costly than Li. Thus, despite its lower energy density, Na ion batteries are promising alternative to Li ion batteries for stationary applications. Other mobile ions such as K, Mg, Zn, Al offer advantages over Li including stability, safety, cost, and are being investigated by our group.

Combining visible-range transparency and electrical conductivity, transparent conducting oxides (TCOs) and transparent semiconducting oxides (TSOs) hold great potential in a variety of applications, including touch screens, flat-panel displays, smart windows, electrochromics, and transparent, flexible, and wearable electronic and sensor devices. In addition, TSOs be used as pixel switching elements emerging transparent displays that operate in standard lighting environments, without backlight, which can reduce power consumption by as much as 90%.

Sensors are being developed in our group based on various sensing mechanisms for wearable and printed sensor applications. Since many of the attributes of materials used for energy storage devices such as large surface area, fast ion and electronic transport, some of the materials developed for energy storage actually work well as sensor materials. Potentiostatic, conductivity-based, capacitance-based, and transistor based sensing devices are being investigated. The applications we are targeting include wearable medical sensors, environmental sensors, and gas sensors. ​

‘Thermoelectrics’ deals with the science and technology of conversion of heat into electricity and vice versa using solid state devices involving no moving parts. We focus on developing thin film and superlattices, as well as thick film thermoelectric materials, with a view to identifying structure-property relations and applying them in the synthesis of better thermoelectric materials and devices. Our research targets thermoelectric material applications in micropower generation and chip cooling.