A5090021390- Advanced Battery Materials and Technologies
- Advancements in Battery Materials
- Advanced NMR Techniques and Applications
- Fuel Cells and Related Materials
- Conducting polymers and applications
- Solid-state spectroscopy and crystallography
- NMR spectroscopy and applications
- Hydrogen Storage and Materials
- Glass properties and applications
- Chalcogenide Semiconductor Thin Films
- Transition Metal Oxide Nanomaterials
- Advanced Battery Technologies Research
- Advanced Condensed Matter Physics
- Membrane-based Ion Separation Techniques
- CO2 Sequestration and Geologic Interactions
- Ionic liquids properties and applications
- Material Dynamics and Properties
- Electron and X-Ray Spectroscopy Techniques
- Supercapacitor Materials and Fabrication
- High-pressure geophysics and materials
- Magnetic Properties and Synthesis of Ferrites
- Quantum Dots Synthesis And Properties
- Diamond and Carbon-based Materials Research
- Advanced MRI Techniques and Applications
- Muon and positron interactions and applications
Hunter College
2007-2023
City University of New York
2002-2021
The Graduate Center, CUNY
2011
City College of New York
2004-2005
Chimie ParisTech
2001
Sorbonne Université
2001
United States Naval Academy
1996-2000
Schlumberger (United States)
1994
Brown University
1989-1990
We demonstrate that, when distributed as nanoscale coatings on the walls of carbon nanofoam substrates, manganese oxides exhibit voltammetric signatures in LiOH-containing alkaline electrolytes that are characteristic either electrochemical capacitors or batteries, depending potential range investigated. Pseudocapacitance is observed for positive ranges, and ex-situ X-ray absorption spectroscopy confirms native layered birnessite MnOx structure retained Mn oxidation state toggled between...
A circular economy in the built environment <italic>via</italic> carbon mineralization of alkaline industrial wastes and silicate minerals <italic>via P</italic><sub>CO2</sub> swing or pH swing, employing acid base generated from electrolysis using renewable energy.
Measurements of the self-diffusion coefficient water in NAFION-117 as a function pressure have been carried out. The natural field gradient 7.3 T superconducting magnet was used for diffusion measurement. measurements were out at 288 K and variable up to 0.25 GPa. high-pressure data obtained four different contents between 6.6 22 wt %. calculated activation volume decreased from 13.2 2.7 cm3/mol content increased These results agree with previously published volumes extracted electric...
Conformal nanoscale coatings of Na+-birnessite manganese oxide (MnOx) produced via redox reaction between aqueous permanganate (NaMnO4·H2O) and the carbon surfaces fiber-paper-supported nanofoams are converted to LiMn2O4 spinel through topotactic exchange Na+ for Li+ in as-deposited lamellar birnessite, followed by mild thermal treatments complete transformation LiMn2O4. The evolution birnessite-to-spinel conversion is verified with X-ray diffraction, solid-state nuclear magnetic resonance,...
Three types of fluorinated carbon, all in their original form and upon sequential chemical lithiations via n-butyllithium, were investigated by (13)C (19)F solid-state NMR methods. The three starting CF(x) materials [where x = 1 (nominally)] fiber based, graphite petroleum coke based. aim the current study was to identify, at atomic/molecular structural level, factors that might account for differences electrochemical performance among different kinds CF(x). Differences noted covalent F...
1H and 31P NMR spectra, line widths, spin–lattice relaxation times (T1), self-diffusion coefficients (D) were determined for two distinct poly(benzimidazole) (PBI) proton exchange membranes (PEM), para-PBI dihydroxy-PBI (2OH-PBI), both incorporating varying concentrations of phosphoric acid. The study was performed over the temperature range 20–180 °C, acid 30, 50, 70 wt %. Of samples, less mobility indicated 2OH-PBI compared with at all concentrations. It also observed that increasing...
Protic ionic liquids (PILs) show great potential as electrolyte components for energy storage devices. A comprehensive understanding of their transport properties must be achieved to optimize the design safer and efficient electrolytes. This study focuses on a series PILs based DBUH+ cation (protonated 1,8-diazabicyclo-[5,4,0]-undec-7-ene superbase) three anions derived from strong acids: TFO− (triflate), IM14− (perfluorobutyl-trifluoromethylsulfonylimide) TFSI− (bis...
Polycrystalline LixV6O13 samples, 0.5⩽x⩽6, were prepared by chemical intercalation in n-butyl lithium and investigated spectroscopically x-ray absorption, electron paramagnetic resonance (EPR), Li7 solid state nuclear magnetic (NMR). Both the EPR results vanadium K-edge absorption fine structure spectra show that average oxidation of decreases with addition Li, provide evidence deficient oxygen impurity phases. The local symmetry atoms first increasing x from 0⩽x⩽1 then increases as...
Alanates have recently attracted attention as new anodic materials for lithium ion batteries. The electrochemical activity of sodium alanate has been already reported and the conversion mechanism explained. Through a complex reaction, this compound is able to develop almost all theoretical capacity, achieving more than 1700 mAh/g upon first discharge with an efficiency 70%. Nevertheless undergoes capacity fade in few cycles. This mainly due severe structural reorganization following that...
The chemical stability of phosphate glasses can be improved through the incorporation nitrogen into structure. In nitrided amorphous thin films (LiPON), exceptional and enhanced conductivity make them particularly attractive for microbattery applications. Reported here are solid-state nuclear magnetic resonance (NMR) studies LiPON fabricated by an ion beam-assisted deposition (IBAD) process. Variable temperature measurements yield activation energy about 0.2 eV, which is smaller than values...
Sodium alanate has proven to be a feasible candidate for electrochemical applications. Within lithium cell, NaAlH4 closely approaches its theoretical capacity of 1985 mAhg−1 upon the first discharge. Despite high specific capacity, suffers from poor cycle efficiency, mostly due severe volume expansion following conversion reaction and resulting in damage electrode mechanical integrity with loss electrical contact. Synthesis an appropriate composite alanate/carbon by energy ball milling...