Our research unearths new knowledge that can aid and address challenges associated with climate change. This includes developing new technologies that can displace fossil fuel-dependent systems and engineering materials to perform better or last longer. Our goal is to advance materials and technologies that accelerate decarbonization efforts.
Operando science
We use advanced characterization tools to study material performance in dynamic conditions.
Materials for Climate
We develop novel materials for separations, including direct air capture and desalination.
Materials for Batteries
We develop batteries for electric vehicles, space applications, and grid energy storage.
We look at technologies that use renewable electrons to do something useful (energy conversion and storage). Broadly, we are interested in applications related to energy storage (batteries) and separations (direct air capture, desalination).
Energy dense batteries are paramount for decarbonization of transportation and grid applications. Replacing traditional graphite anode materials with lithium metal may provide a pathway for increasing the energy density of a Lithium ion battery. However, lithium metal batteries suffer from a range of degradation mechanisms which limits its cycle life and rate performance.
Recently, there has been renewed interest in using a solid electrolyte with lithium metal anodes. A solid electrolyte can act as a barrier for unwanted physical and chemical decomposition that leads to unstable electrodeposition (e.g. dendrite and filament growth). However, numerous experimental investigations have revealed that the mechanical properties of the separator (e.g. solid electrolyte), alone, does not suppress electrically shorting. Instead, the formation and growth of dendrites or filaments is tied to unique chemo-mechanical properties that exists at solid-solid interfaces.
Our work explores the role chemo-mechanics have on the two predominant failure modes in inorganic solid electrolytes: (1) filament formation, and (2) isolated plating. We have specifically examined how material heterogeneity influences reversible operation of lithium metal (e.g. electrode kinetics).
Water plays a critical role in range of chemical, physiochemical, geological, and energy applications. Understanding water at the molecular scale is critical for unraveling processes and mechanisms related to separations, energy storage, and remediation challenges. In this project, we used benchtop and synchrotron techniques to examine CO2 adsorption and desorption in a novel family of moisture-driven CO2 sorbents.
Traditional thermal swing sorption technologies for direct air capture require a large amount of energy during the regeneration process (>179 kJ/mol). An alternative approach to thermal- and pressure-swing sorbents is moisture-driven sorbents. These sorbent materials bind CO2 from the air when the surrounding is dry, and desorbs CO2 when hydrated. This mechanism has been observed in some materials (ion exchange resin, inorganic material, etc.) but is not completely understood.
This work explores how water in confinement can be utilized to tailor CO2 capture and regeneration in advanced sorbent materials. We have found that the sorbent structure, rather than the density of active separation sites, governs the reversible operation of this class of materials.
Rovers utilized in space applications can experience avionic failures in the cryogenic temperatures during lunar nights and Martian winters. Failure is largely attributed to battery failure during these extreme environmental swings.
The current state-of-the-art systems utilize radioisotope heater units (RHUs) and electrical heaters to maintain temperatures above certain thresholds. RHUs are costly and present safety and regulatory challenges for widespread deployment. Freeze tolerant batteries are thus desirable for these missions.
Little is known regarding how batteries transform during freeze-thaw environments due in large part due to the lack of time- and space-resolved experimental techniques capable of observing these material systems. In this project, we explore how freeze-thaw dynamics influence active material utilization. In particular we are excited to develop novel techniques that allow us to probe how battery operate and breakdown in cryogenic environments.
To do this, we fundamentally explore ways to understand materials and material systems at length-scales and time-scales that are close to how they actually operate. We use advanced interrogation probes (x-rays, electrons, and neutrons) to look at a material system (E.g. battery) and understand how it changes during operation. With these observations we try to explore ways that we can engineer materials so they work more efficiently and with longer lifetimes.
