Title: One is the Loneliest Number: Multivalent and Multielectron Processes for Next-Generation Batteries

Kimberly A. See

Division of Chemistry and Chemical Engineering,

California Institute of Technology, Pasadena, CA 91125, USA

Rechargeable Li-ion batteries have revolutionized portable energy storage but the limitations imposed by intercalation chemistry, cost associated with precursors of active materials, and critical nature of crucial elements drive the need for new batteries. 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 that promise high theoretical capacity and energy density. We will discuss how charge storage mechanisms beyond intercalation can be leveraged to yield high energy densities with Fe-based materials. By understanding the fundamental charge storage mechanism in these materials using electrochemical, spectroscopic, and structural characterization tools, we can develop new materials with targeted properties. We will also discuss strategies to go beyond Li working ions looking toward more sustainable ions like Mg²⁺, Ca²⁺, and Zn²⁺. We will take a fundamental look at multivalent ion diffusion in the solid-state: a cornerstone process for the function of multivalent batteries.