scholarly journals Uncovering the roles of oxygen vacancies in cation migration in lithium excess layered oxides

2014 ◽  
Vol 16 (28) ◽  
pp. 14665-14668 ◽  
Author(s):  
Danna Qian ◽  
Bo Xu ◽  
Miaofang Chi ◽  
Ying Shirley Meng
Keyword(s):  
Oxygen Vacancies ◽  
Layered Oxides ◽  
Cation Migration

Regulating Anion Redox and Cation Migration to Enhance the Structural Stability of Li-Rich Layered Oxides

2021 ◽  
Author(s):  
Tianshuo Wang ◽  
Chunxiao Zhang ◽  
Shuwei Li ◽  
Xi Shen ◽  
Liangjun Zhou ◽  
...  
Keyword(s):  
Structural Stability ◽  
Layered Oxides ◽  
Cation Migration

Induction of Bidimensionality in CU-TI Perovskttes

1994 ◽  
Vol 346 ◽  
Author(s):  
M.R. Palacín ◽  
A. Fuertes ◽  
N. Casañ-Pastor ◽  
P. Gómez-Romero
Keyword(s):  
Oxygen Vacancies ◽  
Three Dimensional ◽  
Cation Substitution ◽  
Layered Oxides ◽  
Octahedral Sites

ABSTRACTThe synteses and structure of the three-dimensional perovskite LajCuTiOg are described. In this oxide Cu and Ti atoms are disordered among octahedral sites. The introduction of oxygen vacancies by an adequate cation substitution leads to the induction of bidimensionality as well as an ordered arrangement of cations and oxygen vacancies as found in the layered oxides Ln2Ba2Cu2Ti2O11 (Ln=La,Nd,Eu).

Insight into physicochemical properties of Nd2CuO4±δ and the A-site cation deficient Nd1.9CuO4±δ layered oxides

2020 ◽  
Vol 13 (06) ◽  
pp. 2051034
Author(s):  
Bartłomiej Gȩdziorowski ◽  
Anna Niemczyk ◽  
Anna Olszewska ◽  
Kacper Cichy ◽  
Konrad Świerczek
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Physicochemical Properties ◽  
Oxygen Vacancies ◽  
Numerical Density ◽  
Interstitial Oxygen ◽  
Layered Oxides ◽  
Oxygen Defects ◽  
A Site ◽  
Insight Into

Nd2CuO[Formula: see text] is known to possess either oxygen vacancies or interstitial oxygen defects, depending on the synthesis route, as well as may exhibit the A-site deficiency. In this work, insight into physicochemical properties of Nd2CuO[Formula: see text] and Nd[Formula: see text]CuO[Formula: see text] layered oxides is given, focusing on the crystal structure, electrical conductivity, and oxygen permeation, as well as on numerical density functional theory (DFT) simulations concerning ionic defects formation and their possible movement in the crystal structure. The results indicate that in oxidizing conditions at low temperatures, interstitial oxygen defects are stable, but with the increase of temperature, the release of oxygen is observed, leading to formation of the oxygen vacancies. Both materials are stable at elevated temperatures in air and Ar. Larger oxygen nonstoichiometry and improved electrical conductivity at high temperatures for Nd[Formula: see text]CuO[Formula: see text] compound are accompanied by the recorded oxygen flux of ca. 0.2[Formula: see text]mL[Formula: see text]cm[Formula: see text][Formula: see text]min[Formula: see text] at 880∘C for 0.8[Formula: see text]mm thick ceramic membrane.

scholarly journals Coupling between oxygen redox and cation migration explains unusual electrochemistry in lithium-rich layered oxides

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
William E. Gent ◽  
Kipil Lim ◽  
Yufeng Liang ◽  
Qinghao Li ◽  
Taylor Barnes ◽  
...  
Keyword(s):  
Layered Oxides ◽  
Cation Migration

Structurally Regulating Cation Migration Suppresses Voltage Fade and Redox Asymmetry in Lithium-Rich Layered Oxides

2020 ◽  
Vol MA2020-02 (1) ◽  
pp. 105-105
Author(s):  
Donggun Eum ◽  
Byunghoon Kim ◽  
Sung Joo Kim ◽  
Hyeokjun Park ◽  
Kisuk Kang
Keyword(s):  
Layered Oxides ◽  
Cation Migration ◽  
Voltage Fade

Unveiling the benefits of potassium doping on the structural integrity of Li–Mn-rich layered oxides during prolonged cycling by dual-mode EPR spectroscopy

2019 ◽  
Vol 21 (43) ◽  
pp. 24017-24025 ◽  
Author(s):  
Jianyin Wang ◽  
Mengchu Yang ◽  
Chong Zhao ◽  
Bei Hu ◽  
Xiaobing Lou ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Epr Spectroscopy ◽  
Oxygen Vacancies ◽  
Structural Integrity ◽  
Transition Metal Ions ◽  
Layered Oxides ◽  
Dual Mode

The migration of transition-metal ions and oxygen vacancies in the Li1.2Mn0.6Ni0.2O2 cathode is mitigated after K+ bulk doping.

scholarly journals Persistent and partially mobile oxygen vacancies in Li-rich layered oxides

Nature Energy ◽  
2021 ◽  
Author(s):  
Peter M. Csernica ◽  
Samanbir S. Kalirai ◽  
William E. Gent ◽  
Kipil Lim ◽  
Young-Sang Yu ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Layered Oxides ◽  
Mobile Oxygen

Conditions for atomic imaging of mullite

1989 ◽  
Vol 47 ◽  
pp. 418-419
Author(s):  
T. A. Epicier ◽  
G. Thomas
Keyword(s):  
Oxygen Vacancies ◽  
High Resolution Electron Microscopy ◽  
Ceramic Materials ◽  
Work Conditions ◽  
Real Space ◽  
Potential Candidate ◽  
Silicate Mineral ◽  
Resolution Electron ◽  
The Subject ◽  
Aluminium Silicate

Mullite is an aluminium-silicate mineral of current interest since it is a potential candidate for high temperature applications in the ceramic materials field.In the present work, conditions under which the structure of mullite can be optimally imaged by means of High Resolution Electron Microscopy (HREM) have been investigated. Special reference is made to the Atomic Resolution Microscope at Berkeley which allows real space information up to ≈ 0.17 nm to be directly transferred; numerous multislice calculations (conducted with the CEMPAS programs) as well as extensive experimental through-focus series taken from a commercial “3:2” mullite at 800 kV clearly show that a resolution of at least 0.19 nm is required if one wants to get a straightforward confirmation of atomic models of mullite, which is known to undergo non-stoichiometry associated with the presence of oxygen vacancies.Indeed the composition of mullite ranges from approximatively 3Al2O3-2SiO2 (referred here as 3:2-mullite) to 2Al2O3-1SiO2, and its structure is still the subject of refinements (see, for example, refs. 4, 5, 6).

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