John Goodenough and the Many Lives of Transition-Metal Oxides

<p>Layered sodium transition metal oxides constitute an important class of materials with applications including electrochemical energy storage, high temperature superconductivity and electrocatalysis. However, electrodeposition of these compounds, an approach commonly used to grow other oxides, has been elusive due to their atmosphere instability and intrinsic incompatibility with aqueous electrolytes. Through use of a dry molten sodium hydroxide electrolyte, we demonstrate the high throughput electrodeposition of O3 (O’3) and P2 type layered sodium transition metal oxides across multiple transition metal chemistries, and apply these electrodeposits as high areal capacity cathodes in sodium-ion batteries. The electrodeposits are microns thick, polycrystalline, and structurally similar to materials synthesized classically at high temperature. This work enables fabrication of a wide group of previously inaccessible alkali and alkaline earth ion intercalated, higher valent transition group oxides in important thick film form factors.</p>

Download Full-text

Electrodeposition of Atmosphere-Sensitive Ternary Sodium Transition Metal Oxide Films for Sodium-Based Electrochemical Energy Storage

10.26434/chemrxiv.14394746.v1 ◽

2021 ◽

Author(s):

Arghya Patra ◽

Jerome Davis III ◽

Saran Pidaparthy ◽

Manohar H. Karigerasi ◽

Beniamin Zahiri ◽

...

Keyword(s):

High Temperature ◽

Energy Storage ◽

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

High Temperature Superconductivity ◽

Form Factors ◽

Electrochemical Energy Storage ◽

Wide Group ◽

Electrochemical Energy

<p>Layered sodium transition metal oxides constitute an important class of materials with applications including electrochemical energy storage, high temperature superconductivity and electrocatalysis. However, electrodeposition of these compounds, an approach commonly used to grow other oxides, has been elusive due to their atmosphere instability and intrinsic incompatibility with aqueous electrolytes. Through use of a dry molten sodium hydroxide electrolyte, we demonstrate the high throughput electrodeposition of O3 (O’3) and P2 type layered sodium transition metal oxides across multiple transition metal chemistries, and apply these electrodeposits as high areal capacity cathodes in sodium-ion batteries. The electrodeposits are microns thick, polycrystalline, and structurally similar to materials synthesized classically at high temperature. This work enables fabrication of a wide group of previously inaccessible alkali and alkaline earth ion intercalated, higher valent transition group oxides in important thick film form factors.</p>

Download Full-text

Structural sensitivity of the oxidation reactions catalyzed by dispersed transition metal oxides: role of defect structure

Studies in Surface Science and Catalysis - 3rd World Congress on Oxidation Catalaysis, Proceedings of the 3rd World Congress on Oxidation Catalysis ◽

10.1016/s0167-2991(97)81082-8 ◽

1997 ◽

pp. 1155-1164 ◽

Cited By ~ 6

Author(s):

V.A. Sadykov ◽

S.F. Tikhov ◽

S.V. Tsybulya ◽

G.N. Kryukova ◽

S.A. Veniaminov ◽

...

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Defect Structure ◽

Oxidation Reactions ◽

Structural Sensitivity

Download Full-text

Valence Mapping of Particulate 3D-Transition Metal Oxides Using Energyfiltered Transmission Electron Microscopy

Microscopy and Microanalysis ◽

10.1017/s1431927600033377 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 176-177

Author(s):

R.M. Stroud ◽

J.H. Scott

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Data Extraction ◽

Mixed Valence ◽

Charge Localization ◽

Transmission Electron ◽

Critical Issues

Particulate, mixed-valence transition metal oxides are frequently used for battery, catalytic and magnetic applications. For example, the Li ion exchange battery exploits charge transfer of mixed Mn+3, Mn+4 materials. Charge localization and phase separation, especially at particle surfaces, are critical issues for determining the materials’ useful properties, be it catalytic activity or saturation magnetization. The ability to image the charge localization and correlate this with crystallographic information would be extremely useful in the study of this class of materials. Using energy-filtered transmission electron microscopy (EFTEM), valence maps of Mn and Co with a ∼ 2 nm scale have been obtained for bulk samples. In principal this technique can de directly extended to the case of particulate samples, however there are some additional experimental challenges, such as thickness and edge effects, that must be addressed. We demonstrate here the feasibility of valence mapping of particulate samples, and discuss the factors that limit quantitative data extraction from the maps.

Download Full-text

Electret formation in transition metal oxides by electrochemical amorphization

NPG Asia Materials ◽

10.1038/s41427-019-0187-x ◽

2020 ◽

Vol 12 (1) ◽

Cited By ~ 16

Author(s):

Yong-Jin Kim ◽

Chan-Ho Yang

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Charge Density ◽

Electric Fields ◽

Transition Metal Oxides ◽

Degrees Of Freedom ◽

Permanent Magnets ◽

Underlying Mechanism ◽

Diffusion Reaction ◽

Wide Range

AbstractTransition metal oxides (TMOs) are an important class of materials that show a wide range of functionalities involving spin, charge, and lattice degrees of freedom. The strong correlation between electrons in d-orbitals and the multivalence nature give rise to a variety of exotic electronic states ranging from insulator to superconductor and cause intriguing phase competition phenomena. Despite a burst of research on the multifarious functionalities in TMOs, little attention has been paid to the formation and integration of an electret—a type of quasi-permanent electric field generator useful for nanoscale functional devices as an electric counterpart to permanent magnets. Here, we find that an electret can be created in LaMnO3 thin films by tip-induced electric fields, with a considerable surface height change, via solid-state electrochemical amorphization. The surface charge density of the formed electret area reaches ~400 nC cm−2 and persists without significant charge reduction for more than a year. The temporal evolution of the surface height, charge density, and electric potential are systematically examined by scanning probe microscopy. The underlying mechanism is theoretically analyzed based on a drift-diffusion-reaction model, suggesting that positively charged particles, which are likely protons produced by the dissociation of water, play crucial roles as trapped charges and a catalysis to trigger amorphization. Our finding opens a new horizon for multifunctional TMOs.

Download Full-text