Special Chemistry Seminar

Rechargeable Li-ion batteries have revolutionized portable energy storage but the limitations imposed by intercalation chemistry, the cost associated with precursors of active materials, and the critical nature of vital elements drive the need for new battery chemistries. Our lab aims to develop energy dense chemistries that obviate the need for the critical and costly elements like Co and Ni in the cathode and Li as a working ion. The search for these so called "beyond Li-ion" technologies include systems based on alternative charge storage mechanisms with high theoretical capacity and energy density. To replace Co and Ni, we target Fe-based materials whose energy density can be increased to compete with conventional NMC materials by leveraging multielectron redox. Multielectron redox is enabled by electrochemical access to anionic p bands, which affects not only the electronic structure but also the physical structure. We will discuss a fundamental understanding of this anion redox mechanism, providing both an electronic and physical picture of the process, and how it can be tuned. We will also discuss our efforts to replace Li with more abundant working ions like Mg2+, Ca2+, and Zn2+. Much of this chemistry is limited by a lack of understanding of divalent ionics, which impacts every aspect of the electrochemical cell. We will discuss our efforts to develop materials that can conduct these charge dense ions and the structure-property relationships that govern their mobility. The work discussed here encompasses research themes of redox active materials, solid-state ionics, and metal-liquid interfaces which have impacts beyond batteries to other areas related to sustainability including (but not limited to!) organic electrosynthesis and electrocatalytic production of fuels.