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Synthesis of a family of lithium iron double aryloxide precursors for production of LiFeO2 nanomaterials

Polyhedron

Boyle, Timothy J.; Neville, Michael L.; Apblett, Christopher A.; Pratt, Sarah H.

Lithium iron double aryloxides ([Li2Fe(OAr)4]) were synthesized, characterized, and investigated for use as precursors to LiFeO 2 nanomaterials. From the reaction of iron mesityl, two equivalents of lithium bis(trimethylsilyl) amide, and a series of monosubstituted [HOC 6H4(R)-2 where R = CH3 (oMP), CH(CH 3)2 (oPP), C(CH3)3 (oBP)] or disubstituted [HOC6H3(R)2-2,6 where R = CH 3 (DMP), CH(CH3)2 (DIP), C(CH3) 3 (DBP), C6H5 (DPhP)] aryl alcohols (H-OAr) in tetrahydrofuran (THF) or pyridine (py) were isolated. The mixed-cation Li-Fe precursors that were successfully isolated from this reaction were crystallographically identified as the double aryloxides [Fe((μ-OAr) 2Li(solv)2)2] (OAr = oPP: solv = THF (1), py (2); DMP/THF (3)) and the unusual salt [Li(THF)4][Fe(DBP) 3] (4). For the other OAr/solvent systems investigated, previously published Li or Fe alkoxide compounds or oils were isolated. Compounds 1-4 were further characterized using a variety of analytical methods but the paramagnetic nature of the Fe prevented NMR analyses. The mixed-cation precursors were used for production of nanomaterials following a solvothermal route using dioxane (in place of THF) or pyridine as the solvent. The final materials generated were characterized as the substituted lithium iron oxide structure (LiFeO 2; PDF 01-073-6306). Attempts to cycle the Li in these materials failed to demonstrate appreciable mobile capacity at reasonable potentials; however, a capacity of 87 mAh/g that quickly faded during cycling was observed at very low potentials (start: ∼0.6 V; end: 0.5 V versus Li). © 2013 Elsevier Ltd. All rights reserved.

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TYPE Journal Article YEAR 2013
OSTIScopus

An automated electrochemical probe for evaluation of thin films

Journal of the Electrochemical Society

Small, Leo; Cook, Adam W.; Apblett, Christopher A.; Ihlefeld, Jon I.; Brennecka, Geoffrey L.; Duquette, David

An electrochemical probe station (EPS) for automated electrochemical testing of electronic-grade thin films is presented. Similar in design to a scanning droplet cell, this modular system features a flexible probe tip capable of contacting both metallic and oxide surfaces. Using the highly sensitive Pt-H 2SO 4 system, it is demonstrated that the EPS obtains results equivalent to those of a traditional electrochemical cell. Further, electrical testing of thin film PbZr 0.52Ti 0.48O 3 shows that this system may be used to ascertain fundamental electrical properties of dielectric films. © 2012 The Electrochemical Society.

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TYPE Journal Article YEAR 2012
ScopusOSTI

Fast lithium-ion conducting thin-film electrolytes integrated directly on flexible substrates for high-power solid-state batteries

Advanced Materials

Ihlefeld, Jon I.; Clem, Paul G.; Doyle, Barney L.; Kotula, Paul G.; Fenton, Kyle R.; Apblett, Christopher A.

By utilizing an equilibrium processing strategy that enables co-firing of oxides and base metals, a means to integrate the lithium-stable fast lithium-ion conductor lanthanum lithium tantalate directly with a thin copper foil current collector appropriate for a solid-state battery is presented. This resulting thin-film electrolyte possesses a room temperature lithium-ion conductivity of 1.5 × 10 -5 S cm -1, which has the potential to increase the power of a solid-state battery over current state of the art. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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TYPE Journal Article YEAR 2011
DOIOSTIScopus
Results 51–75 of 90
Results 51–75 of 90