Molten Salt Synthesized MgNiO2 Micro/Nano-Particles for High Energy Density Supercapacitor and Electrocatalyst for Hydrogen Evolution Reaction in Alkaline Medium

2021 ◽  
Vol 21 (11) ◽  
pp. 5556-5568
Author(s):  
S. Maitra ◽  
R. Mitra ◽  
T. K. Nath
Keyword(s):  
Solid Solution ◽  
Energy Density ◽  
Molten Salt ◽  
Hydrogen Evolution ◽  
Alkaline Medium ◽  
Hydrogen Evolution Reaction ◽  
High Energy ◽  
Nano Particles ◽  
High Energy Density ◽  
Phonon Modes

In recent years, solid solutions have shown promising results as functional materials for different applications. These materials have tunable physiochemical properties and electronic properties, and are being intensively studied for next generation electrochemical charge storage as well as noble metal free low cost electrocatalyts. In the present work, Magnesium Nickel Oxide (MgNiO2) solid solution is prepared by molten salt synthesis. MgNiO2 particles having octahedron shaped morphology with size of 550 nm with an agglomerative behavior was observed through morphological studies. Raman studies revealed presence of three two-phonon modes as well as two one-phonon modes, which confirm the phase purity of MgNiO2 sample. MgNiO2 particles behaved as a promising supercapacitor candidate by exhibiting a large specific capacitance of 76 F/g. It also revealed electrochemical stability over an expansive potential range under the presence of 0.5 mol L-1Sodium Sulfate (Na2SO4) electrolyte, having a high energy density of nearly 51 Wh/kg with a power density of nearly 825 w/kg. Further, MgNiO2 particle showed improved electrocatalytic potential towards Hydrogen Evolution Reaction (HER) in 1 mol L-1 Potassium Hydroxide (KOH) alkaline medium, by demonstrating an overpotential of 0.636 V with a Tafel slope of 0.22205 v/dec. Based on these observed promising results, it can be conclusively inferred that MgNiO2 solid solution is a potential candidate for environmental friendly high voltage supercapacitor and HER electrocatalyst applications.

Optimized electron occupancy of solid-solution transition metals for suppressing the oxygen evolution of Li2MnO3

2021 ◽  
Vol 9 (14) ◽  
pp. 9337-9346
Author(s):  
Erhong Song ◽  
Yifan Hu ◽  
Ruguang Ma ◽  
Yining Li ◽  
Xiaolin Zhao ◽  
...  
Keyword(s):  
Solid Solution ◽  
Energy Density ◽  
Transition Metals ◽  
Oxygen Evolution ◽  
High Energy ◽  
High Energy Density ◽  
Li Ion Batteries ◽  
Li Ion ◽  
Increasing Demand ◽  
Layered Cathodes

Li-rich layered cathodes based on Li2MnO3 have exhibited extraordinary promise to satisfy the rapidly increasing demand for high-energy density Li-ion batteries.

Molten Salt Electrochemical Studies and High Energy Density Cell Development

1980 ◽  
pp. 211-222
Author(s):  
A. Bélanger ◽  
F. Morin ◽  
M. Gauthier ◽  
W. A. Adams ◽  
A. R. Dubois
Keyword(s):  
Energy Density ◽  
Molten Salt ◽  
High Energy ◽  
Cell Development ◽  
High Energy Density ◽  
Electrochemical Studies

Combustion of Boron Nano-Particles in Ethanol Spray Flame

2010 ◽  
Author(s):  
Srinibas Karmakar ◽  
Sumanta Acharya ◽  
Kerry M. Dooley
Keyword(s):  
Energy Density ◽  
Particle Surface ◽  
Combustion Process ◽  
High Energy ◽  
Nano Particles ◽  
High Energy Density ◽  
Particle Analysis ◽  
Fuel Additive ◽  
Hydrocarbon Combustion ◽  
Spray Flame

Biofuels such as ethanol have lower energy density than conventional petroleum-based fuels, and therefore enhancing its energy density via addition of high-energy density components is an attractive option. Boron is an attractive fuel additive because it has among the highest volumetric heating value among potentially suitable additives. The present study deals with an experimental investigation of boron combustion in an ethanol spray flame. A constant low particle loading density of boron nanoparticles (60nm SMD), around 1% (by weight) of the liquid fuel flow rate, has been used. Though it has high energetic potential, the combustion process of boron is retarded by the initial presence of the oxide coating the particle surface. In the present study, measurements have been made of the emission of intermediate sub-oxide like BO2 using spectroscopy and imaging with interference filters. The effect of boron on the hydrocarbon combustion has also been studied by examining the heat release and product mole fractions. In addition, particle characterization has been carried out to know the size, surface structure/composition of the injected boron nano powders using XRD, XPS and TEM. A preliminary investigation has also been performed on the burnt particle collected from the exhaust structure using XRD. The chemiluminescence and spectroscopic signatures indicate that boron combustion is facilitated and that hydrocarbon combustion is enhanced. The particle analysis shows differences in the imaged and spectroscopic characteristics of the unburnt and burnt nano-particles reflecting the particle-combustion processes.

Continuous 3D-nanopatterned Ni–Mo solid solution as a free-standing electrocatalyst for the hydrogen evolution reaction in alkaline medium

2021 ◽  
Vol 9 (12) ◽  
pp. 7767-7773
Author(s):  
Kisun Kim ◽  
Anand P. Tiwari ◽  
Gayea Hyun ◽  
Yeoheung Yoon ◽  
Heeyoung Kim ◽  
...  
Keyword(s):  
Solid Solution ◽  
Hydrogen Evolution ◽  
Alkaline Medium ◽  
Hydrogen Evolution Reaction ◽  
Free Standing

A free standing 3D-nanopatterned solid solution of Ni–Mo has been fabricated for excellent hydrogen evolution reaction (HER) activity.

scholarly journals Predicting the crystal structure of $$\hbox {N}_5\hbox {AsF}_6$$ high energy density material using ab initio evolutionary algorithms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
El Mostafa Benchafia ◽  
Xianqin Wang ◽  
Zafar Iqbal ◽  
Sufian Abedrabbo
Keyword(s):  
Crystal Structure ◽  
Energy Density ◽  
Ab Initio ◽  
High Energy ◽  
High Energy Density ◽  
Marginal Stability ◽  
Phonon Modes ◽  
High Energy Density Material ◽  
Polymeric Nitrogen ◽  
Prediction Approach

Abstract$$\hbox {N}_5\hbox {AsF}_6$$ N 5 AsF 6 is the first successfully synthesized salt that has a polymeric nitrogen moeity ($$\hbox {N}_5^+$$ N 5 + ). Although 12 other $$\hbox {N}_5^+$$ N 5 + salts followed, with $$\hbox {N}_5\hbox {SbF}_6$$ N 5 SbF 6 and $$\hbox {N}_5\hbox {Sb}_2\hbox {F}_{11}$$ N 5 Sb 2 F 11 being the most stable, the crystal structure of $$\hbox {N}_5\hbox {AsF}_6$$ N 5 AsF 6 remains unknown. Currently, it is impossible to experimentally determine the structures of $$\hbox {N}_5\hbox {AsF}_6$$ N 5 AsF 6 due to its marginal stability and explosive nature. Here, following an ab initio evolutionary prediction and using only the stoichiometry of $$\hbox {N}_5\hbox {AsF}_6$$ N 5 AsF 6 as a starting point, we were able to reveal the crystal structure of this high energy density material (HEDM). The $$\hbox {C}_{2V}$$ C 2 V symmetry of the $$\hbox {N}_5^+$$ N 5 + cation, as suggested from earlier investigations, is confirmed to be the symmetry adopted by this polymeric nitrogen within the crystal. This result gave full confidence in the validity of this crystal prediction approach. While stability of the $$\hbox {N}_5^+$$ N 5 + within the crystal is found to be driven by electronic considerations, the marginal stability of this HEDM is found to be related to a partial softening of its phonon modes.

Predicting High Energy Density Materials using Abinitio Evolutionary Algorithms: The Results for N5AsF6

2021 ◽  
Author(s):  
El Mostafa Benchafia ◽  
Xianqin Wang ◽  
Zafar Iqbal ◽  
Sufian Abedrabbo
Keyword(s):  
Crystal Structure ◽  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Marginal Stability ◽  
Phonon Modes ◽  
Starting Point ◽  
High Energy Density Material ◽  
Polymeric Nitrogen ◽  
Prediction Approach

Abstract N5AsF6 is the first successfully synthesized salt that has a polymeric nitrogen moeity (N5+). Although 12 other N5+ salts followed, with N5SbF6 and N5Sb2F11 being the most stable, the crystal structure of N5AsF6 remains unknown. Currently, it is impossible to experimentally determine the structures of N5AsF6 due to its marginal stability and explosive nature. Here, following an ab initio evolutionary prediction and using only the stoichiometry of N5AsF6 as a starting point, we were able to reveal the crystal structure of this high energy density material (HEDM). The C2V symmetry of the N5+ cation, as suggested from earlier investigations, is confirmed to be the symmetry adopted by this polymeric nitrogen within the crystal. This result gave full confidence in the validity of this crystal prediction approach. While stability of the N5+ within the crystal is found to be driven by electronic considerations, the marginal stability of this HEDM is found to be related to a partial softening of its phonon modes.

The interplay of Ag and ferromagnetic MgFe2O4 for optimized oxygen-promoted hydrogen evolution via formaldehyde reforming

2021 ◽  
Author(s):  
Jiemei Zhang ◽  
Nan Lu ◽  
Zhengxin Peng ◽  
Sha Li ◽  
Xiaoqing Yan
Keyword(s):  
Energy Density ◽  
Hydrogen Evolution ◽  
High Performance ◽  
High Energy ◽  
Energy Resources ◽  
High Energy Density

Hydrogen is one of the most promising replacement energy resources due to its environmental benignity and high energy density. However, the development of high performance catalyst for efficient and stable...

Sign in / Sign up

Export Citation Format

Share Document