Anne Stevens Assistant Professor Ekaterina Pomerantseva received a five-year National Science Foundation Faculty Early Career Development grant (NSF-CAREER) for her research “Controlling Two-Dimensional Heterointerface in Layered Oxides for Electrodes with Advanced Electrochemical Properties.” This is Pomerantseva’s fourth NSF award since 2016. With this latest source of funding, she aims to mitigate an issue of low electronic conductivity of oxide materials while maintaining their high electrochemical activity and create an entirely new class of ceramic two-dimensional electrodes, in which layers of oxide will be stacked with layers of electronically conductive materials in a controllable sequence. The performance of the electrodes will be evaluated in lithium-, sodium-, and potassium-ion batteries to show the potential of synthesized materials to be used in energy storage devices operating due to reversible cycling of ions with different size and mass. Practically, using sodium and potassium ions will enable cheaper and larger-scale batteries, since sodium and potassium are much more abundant than lithium on Earth.
“When writing this proposal, I was inspired by outstanding research published by my mentors and colleagues. With so many talented scientists in the field of energy storage, I feel privileged to be selected to shed more light on the ways to solve one of the biggest issues of oxide electrodes – their poor electronic conductivity”, said Pomerantseva.
Pomerantseva’s research seeks to advance the next generation of batteries so they can sustain a single charge longer, be able to tolerate high current densities, and have a longer overall life. She will explore new insights into the process of intercalation, a chemical reaction involving the interaction of two “players,” a host material and a “guest” ion, in which the ions move through the crystal structure of the host material.
The intercalation reaction lies at the heart of the operation of multiple devices, such as lithium-ion batteries. And because the reaction is reversible – the ions that were inserted can be withdrawn — the process can occur again and again. This enables the use of batteries throughout their lifetime as opposed to simply through a single charge. “My passion is to make new materials that potentially can facilitate intercalation,” said Pomerantseva. “So when you think about crystal structures of the materials, the structures that favor intercalation properties the most are so-called layered structures. We have layers of the host materials that are separated by these two-dimensional channels. This is the channel that is available for ion intercalation”. The “heterostructure” indicates the presence of a layer of material alternating with layers of another material in a sequence. Pomerantseva will vary the layers and the sequence in which they appear in order to discern what maximizes the intercalation reaction. She believes that while positively charged ions will be inserted and move between the layers, the conducting material layer will enable transport of electrons, leading to advanced performance in intercalation batteries.
“It seems favorable to have these layers being expanded, because we can put more ions in and the capacity will be higher,” she said. Capacity corresponds to the time the battery works off of one charge. So a higher capacity means, for instance, that a smart phone might need to be charged only every week, or longer, opposed to the today’s need to charge a smart phone every 1-2 days. The same will apply to electric cars, which will show much higher mileage between the battery charges.
“This is what’s most interesting in this research,” Pomerantseva added. “These materials have never been synthesized before. I would be excited to be the first one to make such materials and my goal is to establish a new area of research – investigation of two-dimensional heterostructured oxide materials. While my work is focused on energy applications, these new materials can be useful for a broad range of devices and systems.”