AbstractsChemistry

Solvation and exfoliation mechanics of layered transition metal dichalcogenides (TMDs) were studied. Lithium vanadium disulfide (LiVS2) is an alkali-metal intercalate of vanadium disulfide, consisting of 2-dimensional anionic VS2 sheets with interlayer Li cations. X-ray diffraction and potentiometric analysis shows Li(1-x)VS2 undergoes reversible phase changes during oxidative delithiation. An affinity for solvation of the VS2 layers was observed for 0 < x < 0.4 by a range of solvents, while LiVS2 and fully oxidized VS2 show little propensity for direct solvation over short time scales. Understanding the relationship between oxidation state and solvation of TMDs may lead to novel electrolyte formulations that inhibit degradation of electrochemical storage devices over multiple charge cycles. Directed tuning of the interlayer cation density in TMDs such as VS2 may also provide a new means of soft chemical exfoliation and generation of pristine two-dimensional crystalline materials. Advisors/Committee Members: Martin, Benjamin (advisor), Beall, Gary (committee member), Hudnall, Todd (committee member).