BEGIN:VCALENDAR VERSION:2.0 X-WR-CALNAME:EventsCalendar PRODID:-//hacksw/handcal//NONSGML v1.0//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/New_York LAST-MODIFIED:20240422T053451Z TZURL:https://www.tzurl.org/zoneinfo-outlook/America/New_York X-LIC-LOCATION:America/New_York BEGIN:DAYLIGHT TZNAME:EDT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 DTSTART:19700308T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU END:DAYLIGHT BEGIN:STANDARD TZNAME:EST TZOFFSETFROM:-0400 TZOFFSETTO:-0500 DTSTART:19701101T020000 RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT CATEGORIES:College of Arts and Sciences,Lectures and Seminars,Thesis/Disser tations DESCRIPTION:Title:  “Covalent Modification and Characterization of a No naqueous Redox Flow Battery Active Material” Advisor:  Dr. Patrick Capp illino, Chemistry & Biochemistry Dept. Committee Members:  Dr. Sivappa Ra sapalli, Chemistry & Biochemistry Dept.; Dr. Maricris L. Mayes, Chemistry & Biochemistry Dept. ٰ: With the rise in global energy demand, e nvironmental concerns, and technological innovation in renewable energy. R enewable energy sources such as solar, wind, and hydroelectric power have become increasingly prevalent in supporting the electrical grid, both in t he United States and globally. Unfortunately, the major drawback of renewa ble sources is their inability to maintain a constant electrical output. T his intermittency has been one of the main reasons for not having a more h eavily invested renewable power grid. The long-term solution is to increas e the electrical storage grid. This would allow for storing energy produce d during peak times and discharging it when electricity is needed. This ha s paved the way for the development of low-cost and high-efficiency energy storage technology. Among the vast array of potential storage methods, a promising technology is Redox flow batteries. This is because of their hig h adaptability and versatility in the power grid. The development of redox flow batteries using a nonaqueous system has the potential to achieve ene rgy densities similar to those of lithium-ion batteries while maintaining key advantages, such as scalability.   In prior work from the Cappillino lab, vanadium bis-hydroxyiminodiacetate (VBH) has emerged as a promising a ctive material candidate. VBH demonstrated excellent electrochemical stabi lity and highly reversible one-electron redox chemistry. Additionally, VBH exhibits long-term cycle stability. The current drawbacks of this materia l stem from the high viscosity of concentrated solutions, modest voltage, and solubility that, while high, remains insufficient for high-energy-dens ity energy storage applications. This thesis focuses on systematic modific ation of VBH. Herein is outlined the process developed to synthesize these asymmetric, modified compounds. A modular synthetic route was developed i n which substituted bromoacetic acids were incorporated into the HIDA liga nd precursor, enabling systematic alkyl substitution of the resulting vana dium complex. The other component used in the HIDA synthesis is N-hydroxyl glycine, or (NHG), which is the component of HIDA that contains the other carboxylic group and the amine group. The resulting complexes were charact erized by NMR spectroscopy, FTIR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS), while their electrochemical behavior, such as reduction potential, was evaluated using cyclic voltammetry. Three modifi cations were successfully developed, including the addition of methyl-, et hyl-, and butyl- alkyl groups to the precursor material and, consequently, to the final vanadium compound. Furthermore, results indicate a shift in reduction potential upon substitution that could lead to a higher RFB capa city. The overall work establishes a versatile synthetic framework of syst ematic ligand modification of VBH, providing a foundation for future optim ization of nonaqueous redox flow battery active materials.\nEvent page: ht tps://www.umassd.edu/events/cms/20260813-ms-thesis-defense-by-benjamin-dae rmann.php X-ALT-DESC;FMTTYPE=text/html:

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Title:  “Covalent Modificat ion and Characterization of a Nonaqueous Redox Flow Battery Active Materia l”

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Advisor:  Dr. Patrick Cappillino\, Chemistry & Biochemistry Dept.

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Committee Members:  Dr. Sivappa Rasapalli\, Chemistry & Bio chemistry Dept.\; Dr. Maricris L. Mayes\, Chemistry & Biochemistry Dept.< /p>\n

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With the rise in global energy demand\, enviro nmental concerns\, and technological innovation in renewable energy. Renew able energy sources such as solar\, wind\, and hydroelectric power have be come increasingly prevalent in supporting the electrical grid\, both in th e United States and globally. Unfortunately\, the major drawback of renewa ble sources is their inability to maintain a constant electrical output. T his intermittency has been one of the main reasons for not having a more h eavily invested renewable power grid. The long-term solution is to increas e the electrical storage grid. This would allow for storing energy produce d during peak times and discharging it when electricity is needed. This ha s paved the way for the development of low-cost and high-efficiency energy storage technology. Among the vast array of potential storage methods\, a promising technology is Redox flow batteries. This is because of their hi gh adaptability and versatility in the power grid. The development of redo x flow batteries using a nonaqueous system has the potential to achieve en ergy densities similar to those of lithium-ion batteries while maintaining key advantages\, such as scalability.  

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In prior work from the C appillino lab\, vanadium bis-hydroxyiminodiacetate (VBH) has emerged as a promising active material candidate. VBH demonstrated excellent electroche mical stability and highly reversible one-electron redox chemistry. Additi onally\, VBH exhibits long-term cycle stability. The current drawbacks of this material stem from the high viscosity of concentrated solutions\, mod est voltage\, and solubility that\, while high\, remains insufficient for high-energy-density energy storage applications. This thesis focuses on sy stematic modification of VBH. Herein is outlined the process developed to synthesize these asymmetric\, modified compounds. A modular synthetic rout e was developed in which substituted bromoacetic acids were incorporated i nto the HIDA ligand precursor\, enabling systematic alkyl substitution of the resulting vanadium complex. The other component used in the HIDA synth esis is N-hydroxylglycine\, or (NHG)\, which is the component of HIDA that contains the other carboxylic group and the amine group. The resulting co mplexes were characterized by NMR spectroscopy\, FTIR spectroscopy\, and e lectrospray ionization mass spectrometry (ESI-MS)\, while their electroche mical behavior\, such as reduction potential\, was evaluated using cyclic voltammetry. Three modifications were successfully developed\, including t he addition of methyl-\, ethyl-\, and butyl- alkyl groups to the precursor material and\, consequently\, to the final vanadium compound. Furthermore \, results indicate a shift in reduction potential upon substitution that could lead to a higher RFB capacity. The overall work establishes a versat ile synthetic framework of systematic ligand modification of VBH\, providi ng a foundation for future optimization of nonaqueous redox flow battery a ctive materials.

Event page: https://www.umass d.edu/events/cms/20260813-ms-thesis-defense-by-benjamin-daermann.php

DTSTAMP:20260806T115202 DTSTART;TZID=America/New_York:20260813T100000 DTEND;TZID=America/New_York:20260813T120000 LOCATION:SENG 115 SUMMARY;LANGUAGE=en-us:MS Thesis Defense by Benjamin Daermann, “Covalent Modification and Characterization of a Nonaqueous Redox Flow Battery Activ e Material” UID:9f383314c26e8850bca6b47bf888e913@www.umassd.edu END:VEVENT END:VCALENDAR