Performance Improvements by Embedded Thin Film Current Collectors for Microfluidic Fuel Cells With Porous Electrodes

2012 ◽  
Author(s):  
Jin Wook Lee ◽  
Erik Kjeang
Keyword(s):  
Thin Film ◽  
Fuel Cells ◽  
Contact Resistance ◽  
Soft Lithography ◽  
Electrochemical Impedance ◽  
Current Collector ◽  
Porous Electrodes ◽  
Carbon Paper ◽  
Current Collectors ◽  
Contact Points

In the present work, a chip embedded thin film current collector for vanadium fueled microfluidic fuel cells is proposed. Embedded current collectors are expected to increase the number of contact points with the porous electrodes and thereby reduce the overall contact resistance and ohmic losses of the cell. The micromachining based thin film process is compatible with the overall cell fabrication scheme, which is based on soft lithography, and does not require a substantial modification of the original cell design. The flow-through microfluidic fuel cell architecture with porous carbon paper electrodes is used as a proof-of-concept in this study. Our preliminary study shows that the peak power density of the cell with the current collector is increased by 79% at 300 μL min−1 compared to an otherwise identical cell without current collector, indicating that the contact resistance is significantly reduced. Electrochemical impedance spectroscopy analysis is carried out to estimate the overall cell ohmic resistance and confirms a 32% reduction using the current collectors.

scholarly journals Development of a Current Collector with a Graphene Thin Film for a Proton Exchange Membrane Fuel Cell Module

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 955
Author(s):  
Yean-Der Kuan ◽  
Ting-Ru Ke ◽  
Jyun-Long Lyu ◽  
Min-Feng Sung ◽  
Jing-Shan Do
Keyword(s):  
Thin Film ◽  
Proton Exchange Membrane ◽  
Current Collector ◽  
Rf Magnetron Sputtering ◽  
Proton Exchange ◽  
Current Collectors ◽  
Exchange Membrane ◽  
Cell Module ◽  
A Current ◽  
Conduction Layer

This paper constructs planar-type graphene thin film current collectors for proton exchange membrane fuel cells (PEMFCs). The present planar-type current collector adopts FR-4 as the substrate and coats a copper thin film using thermal evaporation for the electric-conduction layer. A graphene thin film is then coated onto the current collector to prevent corrosion due to electrochemical reactions. Three different coating techniques are conducted and compared: Spin coating, RF magnetron sputtering, and screen printing. The corrosion rates and surface resistances are tested and compared for the different coating techniques. Single cell PEMFCs with the developed current collectors are assembled and tested. A PEMFC module with two cells is also designed and constructed. The cell performances are measured to investigate the device feasibility.

High Power Density from Pt Thin Film Electrodes Based Microbial Fuel Cell

2008 ◽  
Vol 8 (8) ◽  
pp. 4132-4134 ◽  
Author(s):  
Tushar Sharma ◽  
A. Leela Mohana Reddy ◽  
T. S. Chandra ◽  
S. Ramaprabhu
Keyword(s):  
Thin Film ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Microbial Fuel Cells ◽  
Neutral Red ◽  
Carbon Paper ◽  
Platinum Electrodes ◽  
Electron Mediator ◽  
Coated Carbon

Microbial Fuel Cells (MFC) are robust devices capable of taping biological energy, converting sugars into potential sources of energy. Persistent efforts are directed towards increasing power output. However, they have not been researched to the extent of making them competitive with chemical fuel cells. The power generated in a dual-chamber MFC using neutral red (NR) as the electron mediator has been previously shown to be 152.4 mW/m2 at 412.5 mA/m2 of current density. In the present work we show that Pt thin film coated carbon paper as electrodes increase the performance of a microbial fuel cell compared to conventionally employed electrodes. The results obtained using E. coli based microbial fuel cell with methylene blue and neutral red as the electron mediator, potassium ferricyanide in the cathode compartment were systematically studied and the results obtained with Pt thin film coated over carbon paper as electrodes were compared with that of graphite electrodes. Platinum coated carbon electrodes were found to be better over the previously used for microbial fuel cells and at the same time are cheaper than the preferred pure platinum electrodes.

The Electrochemical Performance of δ-MnO2 Cathode Material for Aqueous Zinc-Ion Batteries: The Role of Current Collector

2021 ◽  
Vol 105 (1) ◽  
pp. 135-142
Author(s):  
Mikhail A. Kamenskii ◽  
Svetlana N. Eliseeva ◽  
Veniamin V. Kondratiev
Keyword(s):  
Electrochemical Performance ◽  
Current Collector ◽  
Zinc Ion ◽  
Carbon Paper ◽  
Galvanostatic Charge ◽  
Capacity Fading ◽  
Stainless Steel Mesh ◽  
Current Collectors ◽  
Corrosion Of Steel

Electrochemical properties of δ-MnO2-based cathode materials were studied in dependence on current collector used for electrode casting (stainless steel mesh, carbon paper and titanium foil) by galvanostatic charge/discharge measurements and cyclic voltammetry. It was shown that δ-MnO2-based electrodes cast on carbon paper demonstrate the most stable electrochemical performance in comparison with two other current collectors. This can be explained by corrosion of steel and passivation of titanium in mild aqueous electrolytes. Detailed study of carbon paper as current collector shows that pressing of electrodes leads to decreasing the porosity and fast capacity fading.

Carbon Based Electrodes for Upscaling Microfluidic Fuel Cells

2012 ◽  
Author(s):  
D. Fuerth ◽  
A. Bazylak
Keyword(s):  
Fuel Cells ◽  
Surface Area ◽  
Electrode Surface ◽  
Porous Electrode ◽  
Porous Electrodes ◽  
Carbon Paper ◽  
Platinum Black ◽  
Active Electrode ◽  
Flow Through ◽  
Carbon Based

In this work, we present an experimental microfluidic fuel cell with a novel up-scaled porous electrode architecture that provides higher overall power output compared to conventional microfluidic fuel cells and a methodology for electrode material evaluation to inform designs for improved performance. Our proof-of-concept architecture is an up-scaled version of a previously presented flow-through cell with more than nine times the active electrode surface area. We employed 0.04M formic acid and 0.01M potassium permanganate as fuel and oxidant, respectively, dissolved in a 1M sulfuric acid electrolyte. Platinum black was employed as the catalyst for both anode and cathode. Carbon based porous electrodes including felt, cloth, fibre, and foam were compared to traditional Toray carbon paper in order to characterize their respective performances. We also discussed current densities normalized by electrode volume, which is appropriate for comparison of flow-through architectures. The traditional method of current normalization by projected electrode surface area is also presented.

A Parametric Study on Microfluidic Vanadium Fuel Cells

2011 ◽  
Author(s):  
Jin wook Lee ◽  
Deepak Krishnamurthy ◽  
Peter Hsiao ◽  
Erik Kjeang
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Porous Carbon ◽  
Fluid Velocity ◽  
Microfluidic Channel ◽  
Porous Electrodes ◽  
Future Research ◽  
Carbon Paper ◽  
Cell Design ◽  
Channel Network

A parametric variation of microfluidic vanadium fuel cells is studied. The present membraneless and catalyst-free fuel cell consists of a microfluidic channel network with two porous carbon paper electrodes. An aqueous vanadium redox pair as reactants is supplied to the porous electrodes in a flow-through configuration. The dimensions of porous carbon electrodes and microchannels are varied from the baseline design to investigate their impacts on the fuel cell performance. In addition, a dependency on the number of electrical contacts is examined. Numerical simulations are performed in parallel with experimental activities to understand the coupled effects of mass transport, electrochemistry, electron conduction, and fluid velocity field. The simulation results are compared with the measured data from each cell design for verification. An optimal cell design is discussed based on the current study and future research opportunities were proposed.

Low contact resistance carbon thin film modified current collectors for lithium Ion batteries

2014 ◽  
Vol 572 ◽  
pp. 56-60 ◽  
Author(s):  
Shi-Kun Chen ◽  
Kuo-Feng Chiu ◽  
Shih-Hsuan Su ◽  
Shih-Hsien Liu ◽  
Kai Hsiang Hou ◽  
...  
Keyword(s):  
Thin Film ◽  
Contact Resistance ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Current Collectors ◽  
Carbon Thin Film

To Achieve the Best Performance Through Optimization of Gas Delivery and Current Collection in Solid Oxide Fuel Cells

2005 ◽  
Vol 3 (2) ◽  
pp. 188-194 ◽  
Author(s):  
P. W. Li ◽  
S. P. Chen ◽  
M. K. Chyu
Keyword(s):  
Fuel Cell ◽  
Contact Resistance ◽  
Solid Oxide Fuel Cell ◽  
Power Density ◽  
Current Collector ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Electrolyte Layer ◽  
Current Collectors ◽  
Current Collection

Aimed at improving the maximum available power density in a planar-type solid oxide fuel cell, an analytical model is proposed in this work to find the optimum size of a current collector that collects the current from a specific active area of the electrode-electrolyte layer. Distributed three-dimensional current collectors in gas delivery field are designated to allow a larger area of the electrode-electrolyte layer to be active for electrochemical reaction compared to conventional designs that gas channels are separated by current collectors. It has been found that the optimal operating temperature of a planar-type solid oxide fuel cell might be around 850°C, if the sizes of the distributed current collectors and their control areas are optimized. Decreasing the size of both the current collector and its control area is advantageous in achieving a higher power density. Studies also show that the optimal sizes of the current collector and the current collection area investigated at 850°C and zero concentration polarization are applicable to situations of different operating temperatures, and different concentration polarizations. The optimization results of the sizes of current collectors and their control areas are relatively sensitive to the contact resistance between the current collectors and the electrodes of the fuel cell. Results of great significance are provided in the analysis, which will help designers to account for the variation of contact resistance in optimization designing of a bipolar plate of fuel cells.

Up-Scaled Microfluidic Fuel Cells With Porous Flow-Through Electrodes

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
D. Fuerth ◽  
A. Bazylak
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Surface Area ◽  
Electrode Surface ◽  
Porous Electrode ◽  
Porous Electrodes ◽  
Carbon Paper ◽  
Platinum Black ◽  
Flow Through ◽  
Microfluidic Fuel Cell

In this work, an experimental microfluidic fuel cell is presented with a novel up-scaled porous electrode architecture that provides higher available surface area compared to conventional microfluidic fuel cells, providing the potential for higher overall power outputs. Our proof-of-concept architecture is an up-scaled flow-through fuel cell with more than nine times the active electrode surface area of the flow-through architecture first proposed by Kjeang et al. (2008, “A Microfluidic Fuel Cell With Flow-Through Porous Electrodes,” J. Am. Chem. Soc., 130, pp. 4000–4006). Formic acid and potassium permanganate were employed as the fuel and oxidant, respectively, both dissolved in a sulfuric acid electrolyte. Platinum black was employed as the catalyst for both anode and cathode, and the performances of carbon-based porous electrodes including cloth, fiber, and foam were compared to that of traditional Toray carbon paper (TGP-H-120). The effects of catalyst loading were investigated in a microfluidic fuel cell containing 80 pores per linear inch carbon foam electrodes. A discussion is also provided of current density normalization techniques via projected electrode surface area and electrode volume, the latter of which is a highly informative means for comparing flow-through architectures.

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