scholarly journals Iron Disulfide Synthesis for Thermal Batteries Applications

2020 ◽  
pp. 50-53 ◽  
Author(s):  
Gabriel Evangelista Medeiros ◽  
Francisco José Moura ◽  
Rodrigo Fernandes Magalhães de Souza
Keyword(s):  
Current Density ◽  
High Current Density ◽  
High Dispersion ◽  
High Current ◽  
Power Sources ◽  
Iron Disulfide ◽  
Thermal Batteries ◽  
Single Discharge ◽  
Emergency Systems ◽  
Charge Discharge

The necessity for ever more efficient and compact power sources drives the development of more durable and more power-intensive sources. Electrochemical sources include primary batteries that support a single discharge cycle and secondary batteries that support a defined number of charge-discharge cycles. Such sources should be suitable for the intended application, such as emergency systems, military and aerospace apparatus, where they must have long shelf life, high current density and reliability. Thermal batteries work with LiCl-KCl eutectic electrolyte anodes and FeS2 cathodes. A pyrometallurgical synthesis route was studied for roasting reaction between Fe2O3 and vaporized sulfur to obtain FeS2. The results obtained showed a conversion close to 90% and a high dispersion of agglomerates sizes, which disaggregated generate particles suitable for cathode manufacturing.

scholarly journals Effect of Prelithiation Process for Hard Carbon Negative Electrode on the Rate and Cycling Behaviors of Lithium-Ion Batteries

Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 71 ◽  
Author(s):  
Yusuke Abe ◽  
Tomoaki Saito ◽  
Seiji Kumagai
Keyword(s):  
Lithium Ion Batteries ◽  
Current Density ◽  
High Current Density ◽  
Negative Electrode ◽  
Lithium Ion ◽  
High Current ◽  
Hard Carbon ◽  
Li Ion ◽  
Charge Discharge ◽  
Ion Insertion

Two prelithiation processes (shallow Li-ion insertion, and thrice-repeated deep Li-ion insertion and extraction) were applied to the hard carbon (HC) negative electrode (NE) used in lithium-ion batteries (LIBs). LIB full-cells were assembled using Li(Ni0.5Co0.2Mn0.3)O2 positive electrodes (PEs) and the prelithiated HC NEs. The assembled full-cells were charged and discharged under a low current density, increasing current densities in a stepwise manner, and then constant under a high current density. The prelithiation process of shallow Li-ion insertion resulted in the high Coulombic efficiency (CE) of the full-cell at the initial charge-discharge cycles as well as in a superior rate capability. The prelithiation process of thrice-repeated Li-ion insertion and extraction attained an even higher CE and a high charge-discharge specific capacity under a low current density. However, both prelithiation processes decreased the capacity retention during charge-discharge cycling under a high current density, ascertaining a trade-off relationship between the increased CE and the cycling performance. Further elimination of the irreversible capacity of the HC NE was responsible for the higher utilization of both the PE and NE, attaining higher initial performances, but allowing the larger capacity to fade throughout charge-discharge cycling.

Preparation of lignite-based activated carbon with high specific capacitance for electrochemical capacitors

2015 ◽  
Vol 08 (04) ◽  
pp. 1550031 ◽  
Author(s):  
Baolin Xing ◽  
Jianliang Cao ◽  
Yan Wang ◽  
Guiyun Yi ◽  
Chuanxiang Zhang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electron Microscope ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Materials ◽  
High Current Density ◽  
Electrochemical Capacitors ◽  
High Specific Capacitance ◽  
High Current ◽  
Charge Discharge

A lignite-based activated carbon (LAC) for electrochemical capacitors (ECs) was prepared from high moisture lignite by KOH activation, and the as-prepared sample was characterized by the N 2-sorption, scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performances of ECs with activated carbon as electrodes in 3 M KOH aqueous solution were evaluated by constant current charge-discharge and cyclic voltammetry. The LAC exhibits a well-developed surface area of 2581 m2/g, a relative wide pore size distribution of 0.5–10 nm. The ECs with LAC as electrode materials presents a high specific capacitance of 392 F/g at a low current density of 50 mA/g, and still remains 315 F/g even at a high current density of 5 A/g. The residual specific capacitance is as high as 92.9% after 2000 cycles. Compared with the commercial activated carbon (Maxsorb: Commercial product, Kansai, Japan), the LAC based electrode materials shows superior capacitive performance in terms of specific capacitance and charge–discharge performance at the high current density.

scholarly journals High-current density and high-asymmetry MIIM diode based on oxygen-non-stoichiometry controlled homointerface structure for optical rectenna

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Daisuke Matsuura ◽  
Makoto Shimizu ◽  
Hiroo Yugami
Keyword(s):  
Current Density ◽  
Electromagnetic Waves ◽  
High Current Density ◽  
Critical Element ◽  
High Current ◽  
Insulator Layer ◽  
Power Sources ◽  
Wide Range ◽  
Natural Oxide ◽  
High Asymmetry

AbstractOptical rectennas are expected to be applied as power sources for energy harvesting because they can convert a wide range of electromagnetic waves, from visible light to infrared. The critical element in these systems is a diode, which can respond to the changes in electrical polarity in the optical frequency. By considering trade-off relationship between current density and asymmetry of IV characteristic, we reveal the efficiency limitations of MIM diodes for the optical rectenna and suggest a novel tunnel diode using a double insulator with an oxygen-non-stoichiometry controlled homointerface structure (MOx/MOx−y). A double-insulator diode composed of Pt/TiO2/TiO1.4/Ti, in which a natural oxide layer of TiO1.4 is formed by annealing under atmosphere. The diode has as high-current-density of 4.6 × 106 A/m2, which is 400 times higher than the theoretical one obtained using Pt/TiO2/Ti MIM diodes. In addition, a high-asymmetry of 7.3 is realized simultaneously. These are expected to increase the optical rectenna efficiency by more than 1,000 times, compared to the state-of-the art system. Further, by optimizing the thickness of the double insulator layer, it is demonstrated that this diode can attain a current density of 108 A/m2 and asymmetry of 9.0, which are expected to increase the optical rectenna efficiency by 10,000.

Three-dimensional porous copper-decorated bismuth-based nanofoam for boosting electrochemical reduction of CO2 to formate

2021 ◽  
Author(s):  
Yingchun Zhang ◽  
Changsheng Cao ◽  
Xintao Wu ◽  
Qi-Long Zhu
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Three Dimensional ◽  
Co2 Reduction ◽  
Reduction Reaction ◽  
High Current ◽  
Porous Copper ◽  
Reduction Of Co2 ◽  
Co2 Reduction Reaction ◽  
Wide Potential

Bismuth (Bi)-based nanomaterials are considered as the promising electrocatalysts for electrocatalytic CO2 reduction reaction (CO2RR), but it is challenging to achieve high current density and selectivity in a wide potential...

Cu-Doped Alloy Layer Guiding Uniform Li Deposition on a Li–LLZO Interface under High Current Density

2021 ◽  
Author(s):  
Xia He ◽  
Fei Yan ◽  
Mingyuan Gao ◽  
Yunjing Shi ◽  
Guanglong Ge ◽  
...  
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Alloy Layer ◽  
High Current

Implementation of Trigger Unit for Generation of High-Current-Density Electron Beam

2021 ◽  
pp. 1-6
Author(s):  
Anand Abhishek ◽  
Niraj Kumar ◽  
Udit Narayan Pal ◽  
Bhim Singh ◽  
S. A. Akbar
Keyword(s):  
Electron Beam ◽  
Current Density ◽  
High Current Density ◽  
High Current
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