Capacitive matching of pore size and ion size in the negative and positive electrodes for supercapacitors

2011 ◽  
Vol 56 (25) ◽  
pp. 9248-9256 ◽  
Author(s):  
Gangwei Sun ◽  
Wenhua Song ◽  
Xiaojun Liu ◽  
Donghui Long ◽  
Wenming Qiao ◽  
...  
Keyword(s):  
Pore Size ◽  
Positive Electrodes ◽  
Ion Size ◽  
Electrodes For Supercapacitors

Controllable synthesis of hierarchical NiCo2S4@Ni3S2 core–shell nanotube arrays with excellent electrochemical performance for aqueous asymmetric supercapacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 97352-97362 ◽  
Author(s):  
Taobin He ◽  
Senlin Wang ◽  
Fengxia Lu ◽  
Mucan Zhang ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Hydrothermal Reaction ◽  
Nanotube Arrays ◽  
Core Shell ◽  
Controllable Synthesis ◽  
Ni Foam ◽  
Asymmetric Supercapacitors ◽  
Positive Electrodes ◽  
Excellent Electrochemical Performance ◽  
Electrodes For Supercapacitors

Unique NiCo2S4@Ni3S2 core–shell nanotube arrays with a hierarchical structure, as promising positive electrodes for supercapacitors, were designed and synthesized on the surface of Ni foam via a hydrothermal reaction and electrodeposition method.

scholarly journals Relation between the Ion Size and Pore Size for an Electric Double-Layer Capacitor

2008 ◽  
Vol 130 (9) ◽  
pp. 2730-2731 ◽  
Author(s):  
Celine Largeot ◽  
Cristelle Portet ◽  
John Chmiola ◽  
Pierre-Louis Taberna ◽  
Yury Gogotsi ◽  
...  
Keyword(s):  
Pore Size ◽  
Double Layer ◽  
Electric Double Layer ◽  
Electric Double Layer Capacitor ◽  
Double Layer Capacitor ◽  
Ion Size

α -Fe2 O3 /TiO2 Hybrids with Tunable Morphologies as Efficient Photocatalysts and Positive Electrodes for Supercapacitors

2018 ◽  
Vol 3 (11) ◽  
pp. 3284-3294 ◽  
Author(s):  
Mayukh Chakravarty ◽  
Anupam Das ◽  
Chitralee Sarma ◽  
Poulomi Roy
Keyword(s):  
Positive Electrodes ◽  
Electrodes For Supercapacitors

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

1990 ◽  
Vol 48 (4) ◽  
pp. 1094-1095
Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley
Keyword(s):  
Aqueous Solution ◽  
Affinity Chromatography ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Coverage ◽  
Vacuum Impregnation ◽  
Thin Sections ◽  
Selective Staining ◽  
Low Viscosity ◽  
Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

Anionic and Cationic Redox Processes in β-Li2IrO3 and Their Structural Implications on Electrochemical Cycling in Li-Ion Cell

2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Charge Compensation ◽  
Coupling Mechanism ◽  
Redox Processes ◽  
Positive Electrodes ◽  
X Ray ◽  
Electrochemical Cycling ◽  
Li Ion ◽  
Electrochemical Instability ◽  
High Degree

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>

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