As we march forward with vehicle electrification and renewable energy use, cost and sustainability will be the single dominant factor. With a central theme of developing sustainable, clean energy technologies, our targeted, solution-driven research is centered on the development of new materials for batteries and fuel cells with a good balance between basic science and applied science, encompassing the following:
- Design of new materials based on basic chemistry and physics concepts
- Novel chemical synthesis and processing approaches
- Advanced structural, chemical, and surface characterization
- Chemical, physical, and electrochemical property measurements
- Fabrication and evaluation of prototype batteries and fuel cells
- Fundamental understanding of structure-composition-performance relationships
Lithium-ion Batteries: Lithium-ion batteries have aided the revolution in portable electronics. They are now on the verge of transforming the transportation sector and penetrating the utility industry to enable the use of renewable energies. Our research is focused on eliminating the expensive and scarcely available cobalt and increasing the energy density with cathodes having high nickel content.
Metal-sulfur Batteries: Sulfur is abundant, inexpensive, and environmentally benign with 10 times higher charge-storage capacity than the oxide cathodes used in lithium-ion batteries. Unfortunately, metal-sulfur batteries are met with numerous challenges. We are engaged in overcoming the challenges with novel electrode architectures, electrocatalysts, molecular engineering of polysulfides, and robust electrode-electrolyte interphases with necessary cell-assembly parameters in pouch cell configurations to make them commercially viable.
Lithium-metal Stabilization: Among the various metal-sulfur batteries, lithium-sulfur batteries have received much more progress than others, but the lithium-metal anode cycle life is still an impediment. Our research is directed towards stabilizing the lithium-metal anode through an in-situ generation of robust interphases both for cells with sulfur cathode and oxide cathodes.
Sodium-ion Batteries: Sodium is abundant and sodium-ion batteries offer a potential low-cost replacement for lithium-ion batteries. However, they are in their infancy. Our research is engaged in developing new cathode compositions with doping and surface modification to realize long cycle life.
Sodium-metal Stabilization: Ambient-temperature sodium-sulfur batteries represent a “Dream Technology” as both sodium and sulfur are earth-abundant and inexpensive. However, inefficient plating and stripping of sodium and polysulfide shuttling pose serious challenges. Our research is focused towards stabilizing both the sodium-metal anode and sulfur cathode through electrolyte innovation that alters the sodium-sulfur chemistry from dissolution-precipitation reaction into quasi-solid-state reaction.
Multivalent-ion Batteries: Multivalent-ions, such as Zn2+, Mg2+, and Al3+ offer the promise of storing more charge than Li+ and Na+. However, they are plagued by poor reaction kinetics caused by diffusional limitations and lack of electrolytes. Our research is focused on developing new electrode hosts and delineating multivalent-ion vs. proton insertion into the hosts.
All-solid-state Batteries: All-solid-state batteries with a solid electrolyte and solid electrodes are the holy grail of rechargeable batteries as they can offer higher energy density and better safety. However, they are challenged with poor interfacial charge transfer and a lack of suitable electrolytes that can be manufactured over a large area. Our research is aimed at developing optimized interphases with facile charge transfer and manufacturing large-area solid electrolytes with solution-based approaches.
Mediator-ion Solid Electrolyte Batteries: Chemical crossover of soluble species between the electrodes through the porous separator used in traditional batteries often leads to poor efficiency and inferior cycle life. Our group is engaged on the use of a solid-electrolyte separator that can eliminate chemical crossover and allow the use of a variety of solution-based redox active materials at the anode and cathode, including aqueous vs. nonaqueous or acidic vs. basic chemicals.
Solid Oxide Cells: Solid oxide cells based on an oxide-ion solid electrolyte offer high energy efficiency, fuel flexibility, and mechanical stability. They can generate energy by serving as a fuel cell with a fuel and air or produce hydrogen and oxygen from water by serving as an electrolysis cell. Our research involves the development of multifunctional electrode materials for the fuel and air electrodes that offer fast reaction kinetics and/or resistant to coking and sulfur poisoning from hydrocarbon fuels.