Department of Chemistry Seminar - Mike Aubrey

Redox insertion reactions offer a powerful means to predictably access new solid-state structures and phenomena while retaining key structural elements of the parent framework. To date, this class of reactions has been almost exclusively limited to the insertion of monovalent cations—ions that often lack important chemical properties such as redox activity, magnetism, or covalent and metallic bonding character.

In the Aubrey Lab, we have explored a range of crystalline materials capable of reversibly inserting or intercalating divalent and trivalent metal cations and have developed new nonaqueous electrolytes that enable their electrochemical investigation at room temperature. Notably, we recently identified one of the first binary aluminum electrolytes capable of quasi-reversible aluminum metal deposition at room temperature, opening avenues for alternative aluminum electrochemistry that avoids the use of highly corrosive chloride or fluoride ions. In the solid state, we have also demonstrated nonaqueous conditions for the near-stoichiometric insertion of divalent metal cations into Prussian green, granting access to a new class of mixed-valence Prussian blue analogues: A^IIFe^III[Fe^II(CN)₆]. Finally, when materials undergo reductive insertion, the associated lattice expansion can generate mechanical strain, enabling emergent chemomechanical phenomena at solid–solid interfaces. By synthetically modifying the surface chemistry that governs interactions between solids, we can control bulk deformation mechanics within an electrochemical cell. Through this approach, we have developed synthetic analogues of biological muscle with tunable strengths in the range of 10–20 MPa and established an intuitive roadmap for designing new materials with enhanced strength and actuation kinetics.