Charge storage mechanism and degradation of P2-type sodium transition metal oxides in aqueous electrolytes

2018 ◽  
Vol 6 (44) ◽  
pp. 22266-22276 ◽  
Author(s):  
Shelby Boyd ◽  
Rohan Dhall ◽  
James M. LeBeau ◽  
Veronica Augustyn
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Structural Changes ◽  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Storage Mechanism ◽  
Charge Storage Mechanism

P2-type sodium transition metal oxides undergo water-driven structural changes that strongly affect electrochemical charge storage in aqueous electrolytes.

scholarly journals The Role of Al3+-Based Aqueous Electrolytes in the Charge Storage Mechanism of MnOx Cathodes

2020 ◽  
Author(s):  
Véronique Balland ◽  
Mickaël Mateos ◽  
Kenneth D. Harris ◽  
Benoit Limoges
Keyword(s):  
Manganese Oxide ◽  
Critical Analysis ◽  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Storage Mechanism ◽  
Main Charge ◽  
Charge Storage Mechanism ◽  
The Subject

<p>Rechargeable aqueous aluminium batteries are the subject of growing interest, but the charge storage mechanisms at manganese oxide-based cathodes remain poorly understood with as many mechanisms as studies. Here, we use an original <i>in situ</i> spectroelectrochemical methodology to unambiguously demonstrate that the reversible proton-coupled MnO<sub>2</sub>-to-Mn<sup>2+</sup> conversion is the main charge storage mechanism occurring at MnO<sub>2</sub> cathodes over a range of slightly acidic Al<sup>3+</sup>-based aqueous electrolytes. In Zn/MnO<sub>2</sub> assemblies, this mechanism is associated with high gravimetric capacity and discharge potentials, up to 560 mAh·g<sup>-1</sup> and 1.76 V respectively, attractive efficiencies (<i>CE</i> > 98.5 % and <i>EE</i> > 80%) and excellent cyclability (> 750 cycles at 10 A·g<sup>-1</sup>). Finally, we conducted a critical analysis of the data previously published on MnO<sub>x</sub> cathodes in Al<sup>3+</sup>-based aqueous electrolytes to conclude on a universal charge storage mechanism, <i>i.e.</i>, the reversible electrodissolution/electrodeposition of MnO<sub>2</sub>.<i></i></p>

The Charge Storage Mechanism of MnCO 3 in Aqueous Electrolytes

2020 ◽  
Vol 5 (17) ◽  
pp. 5316-5322
Author(s):  
Vishnu Vardhan Palem ◽  
Mustapha Balarabe Idris ◽  
Thiruvenkatam Subramaniam ◽  
Devaraj Sappani
Keyword(s):  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Storage Mechanism ◽  
Charge Storage Mechanism

Pseudocapacitive Contributions to Charge Storage in Highly Ordered Mesoporous Group V Transition Metal Oxides with Iso-Oriented Layered Nanocrystalline Domains

2010 ◽  
Vol 132 (20) ◽  
pp. 6982-6990 ◽  
Author(s):  
Kirstin Brezesinski ◽  
John Wang ◽  
Jan Haetge ◽  
Christian Reitz ◽  
Sven O. Steinmueller ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Charge Storage ◽  
Group V ◽  
Ordered Mesoporous

Phase changes during heat treatment of electrodeposited WO3, MoO3 and V2O5

1992 ◽  
Vol 50 (1) ◽  
pp. 372-373
Author(s):  
G. Veilleux ◽  
A. Guerfi ◽  
R. G. Saint-Jacques ◽  
Lê H. Dao
Keyword(s):  
Heat Treatment ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Structural Changes ◽  
Specific Treatment ◽  
Ambient Air ◽  
Phase Changes ◽  
Scanning Calorimetry ◽  
Fuel Cell Electrodes

Many transition metal oxides have been studied in the last two decades. By an appropriate chemical or electrical means, ions can be inserted into the structure of these oxides with minimal structural changes. This process known as coloration can easily be reversed. This reversible mechanism is of particular interest in applications such as battery and fuel cell electrodes, chemical sensors, electrochromic displays and catalysts.In this study, films of three transition metal oxides (WO3, MoO3, V2O5) were prepared by electrodeposition. The morphology and the structure of these films were analyzed by transmission electron microscopy (TEM) in their as-deposited states and after heat treatment in ambient air up to 500°C. Previous measurements made by differential scanning calorimetry (DSC) showed exothermic peaks corresponding to phase changes. The temperature values determined at those peaks were then chosen as specific treatment temperatures.

A proton-hopping charge storage mechanism of ionic one-dimensional coordination polymers for high-performance supercapacitors

2017 ◽  
Vol 53 (86) ◽  
pp. 11786-11789 ◽  
Author(s):  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
Surasak Kaenket ◽  
Thana Maihom ◽  
Jumras Limtrakul ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Coordination Polymers ◽  
High Performance ◽  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Proton Conducting ◽  
One Dimensional ◽  
Storage Mechanism ◽  
Charge Storage Mechanism

A proton-conducting coordination polymer of Zn2+ phosphate and protonated imidazole has been used as a novel supercapacitor material in aqueous electrolytes.

scholarly journals The Role of Al3+-Based Aqueous Electrolytes in the Charge Storage Mechanism of MnOx Cathodes

2020 ◽  
Author(s):  
Véronique Balland ◽  
Mickaël Mateos ◽  
Kenneth D. Harris ◽  
Benoit Limoges
Keyword(s):  
Manganese Oxide ◽  
Critical Analysis ◽  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Storage Mechanism ◽  
Main Charge ◽  
Charge Storage Mechanism ◽  
The Subject

<p>Rechargeable aqueous aluminium batteries are the subject of growing interest, but the charge storage mechanisms at manganese oxide-based cathodes remain poorly understood with as many mechanisms as studies. Here, we use an original <i>in situ</i> spectroelectrochemical methodology to unambiguously demonstrate that the reversible proton-coupled MnO<sub>2</sub>-to-Mn<sup>2+</sup> conversion is the main charge storage mechanism occurring at MnO<sub>2</sub> cathodes over a range of slightly acidic Al<sup>3+</sup>-based aqueous electrolytes. In Zn/MnO<sub>2</sub> assemblies, this mechanism is associated with high gravimetric capacity and discharge potentials, up to 560 mAh·g<sup>-1</sup> and 1.76 V respectively, attractive efficiencies (<i>CE</i> > 98.5 % and <i>EE</i> > 80%) and excellent cyclability (> 750 cycles at 10 A·g<sup>-1</sup>). Finally, we conducted a critical analysis of the data previously published on MnO<sub>x</sub> cathodes in Al<sup>3+</sup>-based aqueous electrolytes to conclude on a universal charge storage mechanism, <i>i.e.</i>, the reversible electrodissolution/electrodeposition of MnO<sub>2</sub>.<i></i></p>

scholarly journals Structure Changes in Transition Metal Oxides Induced During Electron Microscopy

2001 ◽  
Vol 7 (S2) ◽  
pp. 1096-1097
Author(s):  
D.S. Su ◽  
E. Zeitler ◽  
R. Schlögl
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Structural Changes ◽  
Molybdenum Trioxide ◽  
Layer Structure ◽  
High Vacuum ◽  
Catalytic Materials

Many catalytic materials, especially the maximum valence transition metal oxides, are particularly susceptible to electron beam irradiation and thus undergo structural changes. Hence knowledge about the behaviour of catalytic materials under the electron beam is of importance for all TEM investigations of such materials. On the other hand, this effect can be utilised for an in-situ study of the reductive property, phase transition and/or phase stability of various transition metal oxides in an inert, simple ambient high-vacuum. The knowledge so obtained is needed for understanding the reduction mechanism of catalysts in more complicated chemical environments. in the present work, we study the electron beam induced change in MoO3 and TiO2 (anatase) by means of electron energy-loss spectroscopy (EELS), electron diffraction and high-resolution electron microscopy (HREM).Molybdenum trioxide, MoO3, important as catalyst in the selective oxidation of hydrocarbons, forms an orthorhombic crystal layer structure. Fig. 1 shows oxygen AT-edges recorded at various irradiation periods in a Philips 200 FEG electron microscope.

Relationship between rate performance and electronic/structural changes during oxygen redox of lithium-rich 4d/3d transition metal oxides

2020 ◽  
Vol 357 ◽  
pp. 115459
Author(s):  
Aruto Watanabe ◽  
Kentaro Yamamoto ◽  
Yuki Orikasa ◽  
Masatsugu Oishi ◽  
Koji Nakanishi ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Structural Changes ◽  
Rate Performance
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