Vibrational Spectroscopic Studies of the Local Environment in 4-Volt Cathode Materials

1997 ◽  
Vol 496 ◽  
Author(s):  
C. Julien ◽  
M. Massot ◽  
C. Perez-Vicente ◽  
E. Haro-Poniatowski ◽  
G. A. Nazri ◽  
...  
Keyword(s):  
Transition Metal Oxides ◽  
Cathode Materials ◽  
Local Environment ◽  
Spectroscopic Studies ◽  
Layered Compounds ◽  
Structural Modifications ◽  
Low Temperature Preparation ◽  
Preparation Route ◽  
High Specific Energy ◽  
End Members

ABSTRACTWe report the vibrational spectra of numerous 4-volt cathode materials, the transition metal oxides which are potential materials for advanced Li-ion batteries. They provide high specific energy density, high voltage, and remarkable reversibility for lithium intercalation-deintercalation process. Studied were carried out by Raman and FTIR spectroscopies. Oxides such as LiMn2O4, LiNiVO4, LiCoVO4 spinels, LiMeO2 (Me=Co, Ni, Cr) layered compounds and their mixed compounds have been investigated. The local environment of cations against oxygen neighboring atoms has been determined by considering tetrahedral and octahedral units building the lattice. Structural modifications induced by the intercalation-deintercalation process, by the cation substitution, or by the low-temperature preparation route are also examined. The results are compared with those of end members.

General Overview of Vibrational Spectroscopy of Layered Transition-Metal Oxides

1998 ◽  
Vol 548 ◽  
Author(s):  
C. Julien ◽  
G.A. Nazri
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Local Environment ◽  
Layered Compounds ◽  
Structural Modifications ◽  
Low Temperature Preparation ◽  
Preparation Route ◽  
High Specific Energy ◽  
Layered Transition Metal

ABSTRACTWe report the vibrational spectra of various layered transition-metal oxides, which are potential cathode materials for advanced Li-ion batteries. They provide high specific energy density, high voltage, and remarkable reversibility for lithium intercalation-deintercalation process. Studies were carried out by Raman and FTIR spectroscopies. Oxides such as LiMO2 (M=Co, Ni, Cr) layered compounds and their mixed compounds have been investigated. The local environment of cations against oxygen neighboring atoms has been determined by considering polyhedral units building the lattice. Structural modifications induced by intercalation-deintercalation process, by cation substitution, or by low-temperature preparation route are examined.

scholarly journals Tuning local chemistry of P2 layered-oxide cathode for high energy and long cycles of sodium-ion battery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chenchen Wang ◽  
Luojia Liu ◽  
Shuo Zhao ◽  
Yanchen Liu ◽  
Yubo Yang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Cathode Materials ◽  
Specific Capacity ◽  
High Energy ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Two Phase

AbstractLayered transition-metal oxides have attracted intensive interest for cathode materials of sodium-ion batteries. However, they are hindered by the limited capacity and inferior phase transition due to the gliding of transition-metal layers upon Na+ extraction and insertion in the cathode materials. Here, we report that the large-sized K+ is riveted in the prismatic Na+ sites of P2-Na0.612K0.056MnO2 to enable more thermodynamically favorable Na+ vacancies. The Mn-O bonds are reinforced to reduce phase transition during charge and discharge. 0.901 Na+ per formula are reversibly extracted and inserted, in which only the two-phase transition of P2 ↔ P’2 occurs at low voltages. It exhibits the highest specific capacity of 240.5 mAh g−1 and energy density of 654 Wh kg−1 based on the redox of Mn3+/Mn4+, and a capacity retention of 98.2% after 100 cycles. This investigation will shed lights on the tuneable chemical environments of transition-metal oxides for advanced cathode materials and promote the development of sodium-ion batteries.

Submarine groundwater discharge and alkaline earth element dynamics in a deltaic coastal setting

2016 ◽  
Vol 48 (5) ◽  
pp. 1169-1176 ◽  
Author(s):  
Daniel J. Coleman ◽  
Alexander S. Kolker ◽  
Karen H. Johannesson
Keyword(s):  
Mississippi River ◽  
Submarine Groundwater Discharge ◽  
Alkaline Earth ◽  
Groundwater Discharge ◽  
Local Environment ◽  
Estuarine Water ◽  
Fine Grained ◽  
Alkaline Earth Element ◽  
Submarine Groundwater ◽  
End Members

Submarine groundwater discharge is a process that is often considered negligible in deltaic systems given their low gradient and fine-grained sediment. However, hydrologic budgets and radon surveys indicate that it may be a significant component of the Mississippi River Delta system. To more concretely indicate groundwater's contribution to the local environment, we conducted an analysis of estuarine water chemistry. We focused on the mid-weight alkaline earth metals, which differ significantly in the system's three end-members: river, ocean, and groundwater. We found an anomaly of barium in the estuaries, which could not be completely explained by desorption. Through the construction of a three-end-member mixing model, groundwater was estimated to comprise 14–28% of Terrebonne and Barataria Bay estuarine water, which corresponds to a combined discharge of 160–480 m3/s. This groundwater discharge helps explain the hydrologic budget of the system, and could influence the chemistry of these large deltaic estuaries.

Using Eu 3+ as an atomic probe to investigate the local environment in LaPO 4 –GdPO 4 monazite end-members

2016 ◽  
Vol 483 ◽  
pp. 139-145 ◽  
Author(s):  
Nina Huittinen ◽  
Yulia Arinicheva ◽  
Moritz Schmidt ◽  
Stefan Neumeier ◽  
Thorsten Stumpf
Keyword(s):  
Local Environment ◽  
End Members ◽  
Atomic Probe

scholarly journals Illuminating the Effect of the Local Environment on the Performance of Organic Sunscreens: Insights From Laser Spectroscopy of Isolated Molecules and Complexes

2022 ◽  
Vol 9 ◽  
Author(s):  
Natalie G. K. Wong ◽  
Caroline E. H. Dessent
Keyword(s):  
Laser Spectroscopy ◽  
Electronic Structures ◽  
Rational Design ◽  
Radiative Decay ◽  
Molecular Level ◽  
Alkali Metal Cation ◽  
Local Environment ◽  
Spectroscopic Studies ◽  
Cation Binding ◽  
Laser Spectroscopic

Sunscreens are essential for protecting the skin from UV radiation, but significant questions remain about the fundamental molecular-level processes by which they operate. In this mini review, we provide an overview of recent advanced laser spectroscopic studies that have probed how the local, chemical environment of an organic sunscreen affects its performance. We highlight experiments where UV laser spectroscopy has been performed on isolated gas-phase sunscreen molecules and complexes. These experiments reveal how pH, alkali metal cation binding, and solvation perturb the geometric and hence electronic structures of sunscreen molecules, and hence their non-radiative decay pathways. A better understanding of how these interactions impact on the performance of individual sunscreens will inform the rational design of future sunscreens and their optimum formulations.

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