A5018181390- Advanced Battery Materials and Technologies
- Advancements in Battery Materials
- Advanced Battery Technologies Research
- Advanced battery technologies research
- Fuel Cells and Related Materials
- Supercapacitor Materials and Fabrication
- Electrocatalysts for Energy Conversion
- Conducting polymers and applications
- Extraction and Separation Processes
- Semiconductor materials and devices
- Analytical Chemistry and Sensors
- Gas Sensing Nanomaterials and Sensors
- Chemical Synthesis and Characterization
- Membrane-based Ion Separation Techniques
- Electrochemical Analysis and Applications
- Ammonia Synthesis and Nitrogen Reduction
- Thermal Expansion and Ionic Conductivity
- Solid-state spectroscopy and crystallography
- Molten salt chemistry and electrochemical processes
- Inorganic and Organometallic Chemistry
- Membrane Separation Technologies
- Energetic Materials and Combustion
- Analytical Chemistry and Chromatography
- Membrane Separation and Gas Transport
- BIM and Construction Integration
Oak Ridge National Laboratory
2015-2024
Sandia National Laboratories
1983-2014
Sandia National Laboratories California
1979-2014
Radiology Associates of Albuquerque
1985-2011
Rice University
1975-1979
We report on single-electrode electrochemical impedance spectroscopy studies of an all-vanadium redox battery using a dynamic hydrogen reference electrode. The negative electrode, comprising the V2+/V3+ couple, contributes approximately 80% total cell overpotential during discharge. spectra measured at electrode exhibit high-frequency, semicircular arcs which correspond to double layer capacitance in parallel with faradaic resistance. resistance decreases magnitude increasing polarization....
We present an in situ electrochemical technique for the quantitative measurement and resolution of ohmic, charge transfer diffusion overvoltages at negative electrode all-vanadium redox flow battery (VRFB) using impedance spectroscopy (EIS). The mathematics describing complex V+2/V+3 reaction is derived matches experimental data. voltage losses contributed by each process have been resolved quantified various rates thicknesses as a function current density during anodic cathodic...
In this work, we report methods to quantify and minimize the interfacial resistance for Li ion transport, Rinterface, between a model polymer electrolyte, poly(ethylene oxide) + LiCF3SO3 (PE), Li+-conducting ceramic LICGC from Ohara Corporation. By constructing PE–ceramic–PE trilayer cell, found Rinterface be very large, 1.2 kΩ·cm2 at 30 °C, accounting 66% of total cell resistance. When dimethyl carbonate, loose-binding solvent Li+, was introduced into trilayer, decreased essentially zero....
An innovative approach to improve the energy density of redox flow batteries (RFBs) through electrochemically mediated reactions is demonstrated. Soluble anion radical species (biphenyl and pyrene) mediate reversible sodium storage in a red phosphorus (P) anode located an external packed bed reactor absence binders or conductive additives. Because can be recycled several times cell stack during single charge/discharge cycle, RFB effectively decouples battery's from species' solubility...
Orthorhombic Li2NiO2, Li2CuO2, and solid solutions thereof have been studied as potential cathode materials for lithium-ion batteries due to their high theoretical capacity relatively low cost. While neither endmember shows good cycling stability, the intermediate composition, Li2Cu0.5Ni0.5O2, yields reasonably reversible capacities. A new synthetic approach detailed characterization of this phase parent Li2CuO2 are presented. The cycle life Li2Cu0.5Ni0.5O2 is shown depend critically on...
Through a study of the kinetics hexacyanoferrate redox reaction on passive iron, semiconductor model is proposed for electronic structure oxide film. During passivation, an electron donor incorporated into film by formation and migration interstitial iron ions. The high conductivity unusual Tafel behavior nonintegral orders couple are directly attributed to presence this level. differential capacitance electrode further substantiates structure. approximate concentration ions, , flatband...
Solvent-mediated routes have emerged as an effective, scalable, and low-temperature method to fabricate sulfide-based solid-state electrolytes. However, tuning the synthesis conditions optimize electrolyte's morphology, structure, electrochemical properties is still underexplored. Here, we report a new class of composite solid electrolytes (SEs) containing amorphous Li3PS4 synthesized in situ with poly(ethylene oxide) (PEO) binder using one-pot, solvent-mediated route. The solvent thermal...
A simple electrolyte consisting of NaPF6 salt in 1,2-dimethoxyethane (DME) can extend the voltage window electric double-layer capacitors (EDLCs) to >3.5 V. DME does not passivate carbon electrodes at very negative potentials (near Na/Na+), extending practical by about 1.0 V compared standard, non-aqueous electrolytes based on acetonitrile. The is demonstrated two- and three-electrode cells using a combination electrochemical impedance spectroscopy (EIS), charge-discharge cycling,...
Sodium-based batteries are promising for grid-storage applications because of significantly lower cost compared to lithium-based systems. The advancement solid-state and redox-flow sodium-ion requires exchange membranes with high conductivity, electrochemical stability, mechanical robustness. This study demonstrates that based on poly(ethylene oxide) (PEO) can meet these requirements. Membranes plasticized tetraethylene glycol dimethyl ether (TEGDME) achieve ionic conductivity. Plasticized...
Lithium thiophosphates represent a promising class of solid Li+ conductors for all-solid-state batteries. Scalable solvent-mediated synthesis routes several Li–P–S ternary compounds have been reported, but little is known regarding the reaction mechanism such pathways. This work demonstrates that lithium thiophosphate electrolytes from mixtures Li2S and P2S5 proceeds through highly soluble P2S62– intermediate. intermediate exhibits virtually same Raman spectra in solvents including...
Electrolytes can be contained by capillary forces within high surface area porous media. Ionic conduction these two‐phase composites depends upon the quantity, distribution, and geometric structure of electrolyte solid matrix. In this report, we examine how variables structures influence conductivity such composites. We define using both percolation models random structures. deal specifically with fumed silica molten eutectic which are used in thermal batteries. However, our treatment is...
The plasticization of a polymer electrolyte usually promotes its ionic conductivity but decreases storage modulus due to the increased chain flexibility. Herein, we show that such tradeoff between and mechanical robustness can be alleviated by selective ion-conductive block, as poly(ethylene oxide) (PEO) in polystyrene (PS)− PEO−PS block copolymer (SEO) using an ether type plasticizer, tetraethylene glycol dimethyl (TEGDME). At maximum plasticizer loading, room temperature increases up 3...
The electrochemical reduction of CrO/sub 4//sup 2 -/ proceeds through a Cr(V) intermediate, -3/. reaction this intermediate with the available cations and concentrations these determine overall mechanism ultimate product. In LiCl-KCl eutectic, CaCrO/sub 4/ (> about 0.1m) is reduced to stable Ca/sub 5/(CrO/sub 4/)/sub 3/Cl. CaCl/sub 2//sup KCl-NaCl ternary eutectic 2/CrO/sub 4/Cl. presence Li/sup +/, each compounds further LiCrO/sub 2/. No subsequent 3/Cl or 4/Cl occurs in 2/-KCl-NaCl eutectic.
Effects of salicylaldoxime (SAO) and 8‐hydroxyquinoline (HQ) on the anodic dissolution copper were studied by using a potentiokinetic polarization method phase‐selective a‐c polarography at rotating disk electrode various pH values. At 1.5, where cupric ions do not precipitate as chelates SAO HQ, was retarded slightly these additives. 2.8 5.0, precipitates quantitatively, markedly SAO, especially from electrode. The curves in solutions similar to those obtained passivation iron. A thin...
Impedance measurements are used to determine the electrochemically active surface area of Teflon-bonded, porous carbon current collectors which in Li/SO2 primary cells. An effective pore radius, length, and number also result from these measurements. Results compared BET In 0.1 M LiBr/acetonitrile electrolyte, only a small fraction is active.
Evaluation of the kinetic and thermodynamic characteristics charge transfer reactions requires a reference electrode. Ideally, this electrode should exhibit reproducible, stable, reversible equilibrium potential. In neutral SOCl/sub 2/ electrolyte, Li/LiCl has exhibited acceptable performance in many cases. However, because lithium electrodes must be fabricated handled an inert environment, alternate, less reactive is desirable. One candidate that widely used aqueous non-aqueous...