scholarly journals Effects of Carbon Fiber Compression Ratio and Electrolyte Flow Rate on the Electrochemical Performance of Vanadium Redox Batteries

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhongxu Tai ◽  
Kenzo Hanawa ◽  
Dongying Ju ◽  
Wenping Luo ◽  
Rui Lyu ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Flow Rate ◽  
Compression Ratio ◽  
Coulombic Efficiency ◽  
Internal Resistance ◽  
Electrolyte Flow ◽  
Discharge Performance ◽  
Internal Reaction ◽  
Current Densities ◽  
Carbon Fiber Electrode

All-vanadium flow batteries (VRFBs) are used in the field of energy storage due to their long service life and high safety. In order to further improve the charge-discharge performance of VRFB, this study mainly used the comparative evaluation of VRFB’s carbon fiber electrode compression ratio and electrolyte flow rate. The battery is charged and discharged under different current densities, different compression ratios, and different flow rates. The results show that increasing the compression ratio at different current densities can reduce the internal resistance of the battery, but an excessive compression ratio will accelerate the transfer of vanadium ions, increase the deviation of the electrolyte, and reduce the Coulombic efficiency of the battery. The performance of the battery tends to be balanced when the compression ratio is 30%. At the same time, in the case of the same compression ratio, increasing the flow rate of the electrolyte can reduce the internal reaction resistance of the battery. When the flow reaches a certain value, the influence on the internal resistance will be smaller.

An Investigation of Electrolytic Jet Polishing at High Current Densities

1963 ◽  
Vol 85 (4) ◽  
pp. 395-401 ◽  
Author(s):  
Reno R. Cole ◽  
Yoram Hopenfeld
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Mathematical Analysis ◽  
High Current ◽  
Electrolyte Flow ◽  
Current Densities ◽  
Relationship Of ◽  
The Relationship ◽  
Modified Theory ◽  
Fundamental Mass

A method of polishing metals by means of an electrolytic jet at extremely high current densities (to 1750 amps per sq in.) is described. Data are presented on the relation of polishing effect on various metals to current density and electrolyte flow rate for several electrolytes. An experimental method is described whereby the relationship of the above factors can be determined. It was found that all metals investigated could be polished at high enough current densities. Previous theories of electrolytic polishing are discussed and shown to not fully account for the process investigated. A modified theory to account for polishing at the high current densities observed is presented and is supported by mathematical analysis based on fundamental mass transfer considerations.

Synergistic effect of LiF coating and carbon fiber electrode on enhanced electrochemical performance of Li2MnSiO4

2021 ◽  
Vol 373 ◽  
pp. 137911
Author(s):  
S. Krishna Kumar ◽  
Sourav Ghosh ◽  
Madhushri Bhar ◽  
Ajay K. Kavala ◽  
Sivaraman Patchaiyappan ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Synergistic Effect ◽  
Electrochemical Performance ◽  
Carbon Fiber Electrode ◽  
Enhanced Electrochemical Performance ◽  
Fiber Electrode

The influence of zinc electrode substrate, electrolyte flow rate and current density on zinc-nickel flow cell performance

2021 ◽  
Vol 373 ◽  
pp. 137890
Author(s):  
David P. Trudgeon ◽  
Adeline Loh ◽  
Habib Ullah ◽  
Xiaohong Li ◽  
Vladimir Yufit ◽  
...  
Keyword(s):  
Flow Rate ◽  
Current Density ◽  
Flow Cell ◽  
Cell Performance ◽  
Zinc Electrode ◽  
Electrolyte Flow ◽  
Zinc Nickel

Electrochemical sensor for nitric oxide using layered films composed of a polycationic dendrimer and nickel(II) phthalocyaninetetrasulfonate deposited on a carbon fiber electrode

2014 ◽  
Vol 182 (5-6) ◽  
pp. 1079-1087 ◽  
Author(s):  
Juliana Cancino ◽  
Sabine Borgmann ◽  
Sergio A. S. Machado ◽  
Valtencir Zucolotto ◽  
Wolfgang Schuhmann ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Fiber ◽  
Electrochemical Sensor ◽  
Carbon Fiber Electrode ◽  
Fiber Electrode

Fabrication and Characterization of Anode-Supported SDC Film Electrolyte and its Single Cell

2010 ◽  
Vol 177 ◽  
pp. 407-410
Author(s):  
Xi Bao Li ◽  
Jian Wang ◽  
Xiao Hua Yu ◽  
Hong Xing Gu ◽  
Gang Qin Shao
Keyword(s):  
Single Cell ◽  
Power Density ◽  
Flow Rate ◽  
Current Density ◽  
Tape Casting ◽  
Threshold Value ◽  
Interface Layer ◽  
Open Circuit ◽  
Discharge Performance ◽  
Film Electrolyte

NiO-YSZ (NiO-yttria stabilized zirconia, 3:2, wt.%) and samaria doped ceria (SDC) tapes were prepared by aqueous tape casting. NiO-YSZ anode-supported SDC film electrolyte half-cell was fabricated by laminating and co-sintering at 1400°C for 2 h. The single cell was prepared after LSCF-SDC (lanthanum strontium cobalt ferrite-SDC, 1:1, wt.%) cathode was coated on the electrolyte surface and sintered at 1300 °C for 2 h. The discharge performance of the single cell was tested from 500 °C to 800 °C at different H2 flow rate. Results showed that the relationship between current (I) of and H2 flow rate (ν) was I = 8 × 106 ν. Before reaching the threshold value of H2 flow rate, the current density of single cell increased with the increasing of H2 flow rate. However, the current density did not change with increasing of H2 flow rate over the threshold value. The open circuit voltage (OCV) of single cell at 500°C, 600°C, 700°C, 800°C was 0.978, 0.921, 0.861, 0.803 V, respectively. The maximum power density reached 93.03 mW/cm2 at 800°C. The resistance of interface layer between Ni-YSZ anode and SDC electrolyte was the key impact on the power density.

Principle and structure of a multi-chamber piezoelectric pump with large flow rate integrated into printed circuit board

2022 ◽  
pp. 1045389X2110721
Author(s):  
Yun-Hao Peng ◽  
Dai-Hua Wang ◽  
Lian-Kai Tang
Keyword(s):  
Flow Rate ◽  
Compression Ratio ◽  
Layer Structure ◽  
Experimental Results ◽  
Processing Technology ◽  
Rate Model ◽  
Piezoelectric Pump ◽  
Central Deflection ◽  
Maximum Value ◽  
Large Flow

Parametric simulation of multi-chamber piezoelectric pump proposed by authors shows that its flow rate is positively correlated with chamber compression ratio when height of chamber wall is not less than central deflection of circular piezoelectric unimorph actuator (CPUA). Therefore, in this paper, principle and structure of multi-chamber piezoelectric pump with novel CPUAs with three-layer structure are proposed and realized, so as to improve its chamber compression ratio, and then improve its flow rate. Its processing technology compatible with PCB processing technology is studied and its flow rate model is established. Central deflection of CPUA with three-layer structure and the flow rate characteristics are tested. Experimental results show that when the central deflection of CPUA with three-layer structure reaches the maximum value of 106.8 μm, the chamber compression ratio and flow rate of multi-chamber piezoelectric pump reach the maximum value of 50% and 3.11 mL/min, respectively. The maximum flow rate is increased by 622% compared to unimproved pump. By comparing experimental results with numerical and finite element simulation results, the realized multi-chamber piezoelectric pump has large flow rate and the established flow rate model can predict its flow rate.

scholarly journals CoMnO2-Decorated Polyimide-Based Carbon Fiber Electrodes for Wire-Type Asymmetric Supercapacitor Applications

2020 ◽  
Author(s):  
Young-Hun Cho ◽  
Jae-Gyoung Seong ◽  
Jae-Hyun Noh ◽  
Da-Young Kim ◽  
Yong-Sik Chung ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Rate Capability ◽  
Ammonium Persulfate ◽  
Chemical Oxidation ◽  
Sem Analysis ◽  
Metal Nanostructures ◽  
Carbon Fiber Electrode ◽  
Coated Carbon ◽  
Fiber Electrode

In this work, we report the carbon fiber-based wire-type asymmetric supercapacitors (ASCs). The highly conductive carbon fibers were prepared by the carbonized and graphitized process using the polyimide (PI) as a carbon fiber precursor. To assemble the ASC device, the CoMnO2-coated and Fe2O3-coated carbon fibers were used as the cathode and the anode materials, respectively. FE-SEM analysis confirmed that the CoMnO2-coated carbon fiber electrode exhibited the porous hierarchical interconnected nanosheet structures, depending on the added amounts of ammonium persulfate (APS) as an oxidizing agent, and Fe2O3-coated carbon fiber electrode showed a uniform distribution of porous Fe2O3 nanorods over the surface of carbon fibers. The nanostructured CoMnO2 were directly deposited onto carbon fibers by a chemical oxidation route without high temperature treatments. In particular, the electrochemical properties of the CoMnO2-coated carbon fiber with the concentration of 6 mmol APS presented the enhanced electrochemical activity, probably due to its porous morphologies and good conductivity. Further, to reduce the interfacial contact resistance as well as improve the adhesion between transition metal nanostructures and carbon fibers, the carbon fibers were pre-coated with the Ni layer as a seed layer using an electrochemical deposition method. The fabricated ASC device delivered a specific capacitance of 221 F g-1 at 0.7 A g-1 and good rate capability of 34.8% at 4.9 A g-1. Moreover, the wire-type device displayed the superior energy density of 60.16 Wh kg-1 at a power density of 490 W kg-1 and excellent capacitance retention of 95% up to 3,000 charge/discharge cycles.

A Study of the Determination of Cu(II) by Anodic Stripping Voltammetry on a Novel Nylon/Carbon Fiber Electrode

2004 ◽  
Vol 16 (7) ◽  
pp. 524-531 ◽  
Author(s):  
A. Mylonakis ◽  
A. Economou ◽  
P. R. Fielden ◽  
N. J. Goddard ◽  
A. Voulgaropoulos
Keyword(s):  
Carbon Fiber ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Anodic Stripping ◽  
Carbon Fiber Electrode ◽  
Fiber Electrode
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