Our research program is concerned with developing advanced energy storage and conversion technologies with an emphasis on understanding the fundamental electrochemistry that controls device performance.
Flow batteries are an emerging large-scale energy storage technology that may enable intermittent power sources, including renewables, to make up a greater portion of our future power supply infrastructure. High round-trip efficiency, the absence of electrode transformations, and decoupled power-energy scaling all make RFBs attractive for energy storage. Flow batteries share similarities with fuel cells and secondary batteries, and we are addressing these hybrid devices with varied approaches. In addition to efforts to improve the performance of existing flow battery technologies, we are developing innovative battery chemistries for next-generation devices.
Studying polymer-based electrolytes is the core capability of the team. We study
these materials from the most fundamental levels to their application in devices.
Polymer electrolytes are used in a plethora of devices, including fuel cells, flow
batteries and other ‘open’ batteries (e.g. metal-air batteries), electrosynthesis cells ,
sensors and so on. We study materials developed by others (3M, Sandia National
Lab) and we make our own materials. Material types we study include cation- and
anion-conductors and range from solid polymer membranes in which only water is
needed to enhance conduction, electrolytes that are essentially gels filled with ion-
conducting fluid, nanocomposites and solid organic conductors. We also apply a
broad range of methods for studying these materials, ranging from thermodynamic
methods to spectroscopic methods and transport measurements as well as physical
tests. We often invent or extend methods to provide the precise information needed
to understand the specific behavior we want to probe. We have also used
computational methods for studying these materials.
Solid Acid Fuel Cells
Solid acid fuel cells (SAFCs) based on the superprotonic electrolyte CsH2PO4 (CDP) are a relatively new technology with the potential for generating electrical power from renewable fuels at a low cost. By virtue of an intermediate operating temperature (235 C - 265 C), SAFCs are distinct from other fuel cell technologies. Due in part to this novelty little is known about catalysis of the oxygen reduction reaction (ORR) in the SAFC system. Understanding the ORR under such hot and dry conditions is necessary for advancing not only SAFC technology, but also polymer electrolyte (PEMFC) systems, which maintain operation at low humidity and elevated temperatures as a major goal.
The applicability of catalytic energy conversion devices such as fuel cells and photochemical cells is limited by a reliance on precious metal catalysts. To address this we are developing a set of non-precious oxygen reduction electrocatalysts based on a biomimetic approach. In contrast with pyrolysis-based synthesis, our catalysts rely on the attachment of nitrogenated ligand-transition metal complexes to carbon surfaces, permitting a more mechanistic approach to engineering active sites for oxygen reduction.