Defect chemical studies on oxygen release from the Li-rich cathode material Li1.2Mn0.6Ni0.2O2−δ

2019 ◽  
Vol 7 (9) ◽  
pp. 5009-5019 ◽  
Author(s):  
Takashi Nakamura ◽  
Hongze Gao ◽  
Kento Ohta ◽  
Yuta Kimura ◽  
Yusuke Tamenori ◽  
...  
Keyword(s):  
Cathode Material ◽  
Defect Chemistry ◽  
Oxygen Release ◽  
Chemical Studies

Oxygen release from a Li-rich cathode material was quantitatively evaluated and discussed based on defect chemistry and thermodynamics.

Improvement of the cyclic deterioration and structural evolution of Li[Li0.2Ni0.2Mn0.6]O2 cathode material by controlling initial charging voltages

RSC Advances ◽  
2016 ◽  
Vol 6 (28) ◽  
pp. 23677-23685 ◽  
Author(s):  
Wuwei Yan ◽  
Yongning Liu ◽  
Shaokun Chong ◽  
Yi-Fang Wu
Keyword(s):  
Phase Transformation ◽  
Cathode Material ◽  
Spinel Phase ◽  
Structural Evolution ◽  
Oxygen Release

The initial stepwise charging suppresses oxygen release and restrains the layered to spinel phase transformation.

scholarly journals Defect chemistry and lithium-ion migration in polymorphs of the cathode material Li2MnSiO4

2013 ◽  
Vol 1 (13) ◽  
pp. 4207 ◽  
Author(s):  
Craig A. J. Fisher ◽  
Navaratnarajah Kuganathan ◽  
M. Saiful Islam
Keyword(s):  
Cathode Material ◽  
Lithium Ion ◽  
Defect Chemistry ◽  
Ion Migration

scholarly journals Long-range oxygen ordering linked to topotactic oxygen release in Pr2NiO4+δ fuel cell cathode material

2020 ◽  
Vol 8 (28) ◽  
pp. 13987-13995 ◽  
Author(s):  
Rajesh Dutta ◽  
Avishek Maity ◽  
Anna Marsicano ◽  
Monica Ceretti ◽  
Dmitry Chernyshov ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Cathode Material ◽  
Single Crystal ◽  
Long Range ◽  
Room Temperature ◽  
Oxygen Release ◽  
Synchrotron Diffraction ◽  
Oxygen Ordering ◽  
Fuel Cell Cathode ◽  
Oxygen Membrane

Complex oxygen ordering evidenced for the oxygen membrane cathode material Pr2NiO4.25 at room temperature with translational periodicities attaining almost 100 Å by single-crystal synchrotron diffraction studies.

scholarly journals Defect Chemistry and Na-Ion Diffusion in Na3Fe2(PO4)3 Cathode Material

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1348 ◽  
Author(s):  
Navaratnarajah Kuganathan ◽  
Alexander Chroneos
Keyword(s):  
Activation Energy ◽  
Computational Modeling ◽  
Cathode Material ◽  
Iron Phosphate ◽  
Defect Chemistry ◽  
Intrinsic Defect ◽  
Ion Diffusion ◽  
Energy Process ◽  
Modeling Techniques ◽  
Diffusion Paths

In this work, we employ computational modeling techniques to study the defect chemistry, Na ion diffusion paths, and dopant properties in sodium iron phosphate [Na3Fe2(PO4)3] cathode material. The lowest intrinsic defect energy process (0.45 eV/defect) is calculated to be the Na Frenkel, which ensures the formation of Na vacancies required for the vacancy-assisted Na ion diffusion. A small percentage of Na-Fe anti-site defects would be expected in Na3Fe2(PO4)3 at high temperatures. Long-range diffusion of Na is found to be low and its activation energy is calculated to be 0.45 eV. Isovalent dopants Sc, La, Gd, and Y on the Fe site are exoergic, meaning that they can be substituted experimentally and should be examined further. The formation of Na vacancies and Na interstitials in this material can be facilitated by doping with Zr on the Fe site and Si on the P site, respectively.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Ultrastructural Localization of Acetylcholinesterase in the Arcuate Nucleus and Median Eminence of the Rat

1977 ◽  
Vol 35 ◽  
pp. 440-441
Author(s):  
K.A. Carson ◽  
C.B. Nemeroff ◽  
M.S. Rone ◽  
J.S. Kizer ◽  
J.S. Hanker
Keyword(s):  
Choline Acetyltransferase ◽  
Median Eminence ◽  
Arcuate Nucleus ◽  
Cholinergic Neurons ◽  
Ultrastructural Localization ◽  
Male Rats ◽  
Neonatal Rats ◽  
Good Marker ◽  
Chemical Studies ◽  
High Doses

Biochemical, physiological, pharmacological, and more recently enzyme histo- chemical data have indicated that cholinergic circuits exist in the hypothalamus. Ultrastructural correlates of these pathways such as acetylcholinesterase (AchE) positive neurons in the arcuate nucleus (ARC) and stained terminals in the median eminence (ME) have yet to be described. Initial studies in our laboratories utilizing chemical lesioning and microdissection techniques coupled with microchemical and light microscopic enzyme histo- chemical studies suggested the existence of cholinergic neurons in the ARC which project to the ME (1). Furthermore, in adult male rats with Halasz deafferentations (hypothalamic islands composed primarily of the isolated ARC and the ME) choline acetyltransferase (ChAc) activity, a good marker for cholinergic neurons, was not significantly reduced in the ME and was only somewhat reduced in the ARC (2). Treatment of neonatal rats with high doses of monosodium 1-glutamate (MSG) results in a lesion largely restricted to the neurons of the ARC.

Dislocations, Ordering and Antiferromagnetic Domains in MnO

1970 ◽  
Vol 28 ◽  
pp. 522-523
Author(s):  
D. J. Barber ◽  
R. G. Evans
Keyword(s):  
Electron Diffraction ◽  
Single Crystal ◽  
Optical Microscopy ◽  
Defect Chemistry ◽  
Magnetic Structures ◽  
Optically Transparent ◽  
Magnetic Features ◽  
Antiferromagnetic Domains

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.

Structural and Chemical Studies of Pathological Fibers in Human Neurofibrillary Degeneration

1985 ◽  
Vol 43 ◽  
pp. 726-729
Author(s):  
K.S. Kosik ◽  
L.K. Duffy ◽  
S. Bakalis ◽  
C. Abraham ◽  
D.J. Selkoe
Keyword(s):  
Monoclonal Antibodies ◽  
Alzheimer Disease ◽  
Human Brain ◽  
Neurofibrillary Tangles ◽  
Morphological Analysis ◽  
High Specificity ◽  
Cytoskeletal Proteins ◽  
Neuritic Plaque ◽  
Protein Chemistry ◽  
Chemical Studies

The major structural lesions of the human brain during aging and in Alzheimer disease (AD) are the neurofibrillary tangles (NFT) and the senile (neuritic) plaque. Although these fibrous alterations have been recognized by light microscopists for almost a century, detailed biochemical and morphological analysis of the lesions has been undertaken only recently. Because the intraneuronal deposits in the NFT and the plaque neurites and the extraneuronal amyloid cores of the plaques have a filamentous ultrastructure, the neuronal cytoskeleton has played a prominent role in most pathogenetic hypotheses.The approach of our laboratory toward elucidating the origin of plaques and tangles in AD has been two-fold: the use of analytical protein chemistry to purify and then characterize the pathological fibers comprising the tangles and plaques, and the use of certain monoclonal antibodies to neuronal cytoskeletal proteins that, despite high specificity, cross-react with NFT and thus implicate epitopes of these proteins as constituents of the tangles.

Diffraction analysis of the lithium battery cathode material Li1.2Mn0.4Ni0.3Co0.1O2

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 483-488
Author(s):  
P. S. Whitfield ◽  
I. J. Davidson ◽  
P. W. Stephens ◽  
L. M. D. Cranswick ◽  
I. P. Swainson
Keyword(s):  
Cathode Material ◽  
Diffraction Analysis ◽  
Lithium Battery
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