MRL Room 2053
Speaker
Alexis Grimaud, PhD
Assistant Professor, Department of Chemistry, Boston College.
Host
Prof. Raphaële Clément
At the heart of the Li-ion battery technology lies intercalation chemistry. To achieve reversible intercalation, delicate balance between materials and liquid electrolytes is necessary to avoid parasitic reactions, including electrolyte decomposition or materials dissolution or decomposition. This balance has thus far limited intercalation materials to oxides or sulfides. Using an electrolyte engineering approach, we have shown that Li can be reversibly intercalated in transition metal layered tri-halides MX3 (with X = Cl, Br or I), materials previously studied for their magnetic and electronic properties. This work has opened up a new family of intercalation phases with versatile design properties, including A2MCl4 phases (A = Li and Na and M being 3d transition metals) for which structural and electronic properties control their reactivity with Li and Na. We are now exploring the intercalation properties of mixed-anion compounds. Using a similar electrolyte engineering approach, we have demonstrated that full Li intercalation can be achieved in iron oxychloride FeOCl, a material previously known to undergo structural degradations in conventional electrolytes. Building upon this finding, the influence of anion mixing in redox and diffusion properties is investigated by comparing chalcogenides with chlorides, oxychlorides and emerging transition metal sulfochlorides.
Bio: Alexis Grimaud is an Assistant Professor of Chemistry at Boston College. Prior to this position, he was a CNRS Researcher in the Solid-State Chemistry and Energy Laboratory, at Collège de France, Paris, from 2014 to 2022. His research lies at the frontier between materials science for the design of redox active materials and physical chemistry of liquid electrolytes. He applies these principles to understand and develop efficient electrochemical energy storage and conversion devices with an emphasis on secondary (rechargeable) batteries, water electrolyzers and the electrosynthesis of commodity chemicals.