[go: up one dir, main page]

WO2009006594A1 - Procédé et appareil de mesure de concentration de réactif d'interface dans un dispositif électrochimique - Google Patents

Procédé et appareil de mesure de concentration de réactif d'interface dans un dispositif électrochimique Download PDF

Info

Publication number
WO2009006594A1
WO2009006594A1 PCT/US2008/069203 US2008069203W WO2009006594A1 WO 2009006594 A1 WO2009006594 A1 WO 2009006594A1 US 2008069203 W US2008069203 W US 2008069203W WO 2009006594 A1 WO2009006594 A1 WO 2009006594A1
Authority
WO
WIPO (PCT)
Prior art keywords
fuel
fuel cell
methanol
concentration
current density
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2008/069203
Other languages
English (en)
Inventor
Hongtan Liu
Jiahua Han
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Miami
Original Assignee
University of Miami
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Miami filed Critical University of Miami
Publication of WO2009006594A1 publication Critical patent/WO2009006594A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
    • H01M8/04537—Electric variables
    • H01M8/04574—Current
    • H01M8/04589—Current of fuel cell stacks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
    • H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
    • H01M8/04104—Regulation of differential pressures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
    • H01M8/04186—Arrangements for control of reactant parameters, e.g. pressure or concentration of liquid-charged or electrolyte-charged reactants
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
    • H01M8/04197—Preventing means for fuel crossover
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04305—Modeling, demonstration models of fuel cells, e.g. for training purposes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
    • H01M8/0438—Pressure; Ambient pressure; Flow
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1009—Fuel cells with solid electrolytes with one of the reactants being liquid, solid or liquid-charged
    • H01M8/1011—Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M2008/1095—Fuel cells with polymeric electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
    • H01M2008/1293—Fuel cells with solid oxide electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/14—Fuel cells with fused electrolytes
    • H01M2008/147—Fuel cells with molten carbonates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
    • H01M8/0444—Concentration; Density
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/08—Fuel cells with aqueous electrolytes
    • H01M8/086—Phosphoric acid fuel cells [PAFC]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • Direct methanol fuel cell is a promising energy conversion device for the future.
  • DMFC Direct methanol fuel cell
  • methanol crossover from the anode to the cathode is a serious problem that severely reduces the cell voltage, current density, fuel utilization and hence the cell performance. Since methanol can be dissolved into water to any degree and the commonly used solid polymer electrolyte, Nafion®, readily absorbs water as well as methanol, methanol crossover is thus unavoidable with the current DMFC technology.
  • Methanol crossover in a DMFC includes three parts, the diffusion part, the electro-osmosis part and the penetration part caused by the pressure difference between the anode side and cathode side of the electrolyte membrane. All of these three parts are directly related to the methanol concentration at the interface between the anode catalyst layer and the electrolyte membrane. The methanol concentration at this interface is also a direct criterion for the total catalytic performance of the anode catalyst layer. The ratio among the carbon(graphite), catalyst and electrolyte, the manufacture techniques which determine the structure of catalyst layer, all these effectors effect the methanol concentration at this interface and so is the cell performance.
  • One embodiment of the invention is directed to a method for measuring an interface fuel concentration (interface reactant concentration) and a fuel drag coefficient in an electro-chemical device - such as a fuel cell
  • the method involves a first step of measuring a first transient fuel crossover rate and a first post change current density of the fuel cell as the fuel cell transitions from one current density (I]) to a second different current density (I2).
  • the second step involves measuring a second transient fuel crossover rate and a second post change current density of the fuel cell as the fuel cell transitions from one current density (I 1 ) to a third different current density (I 3 ),
  • an interface fuel concentration and a fuel drag coefficient is determined based on the previously collected measurements (first and the second transient fuel crossover rate and the first and the second post change current density).
  • I 1 , 1 2 and I 3 are each of a different value but they can be of any relation to each other.
  • the transient fuel crossover rate may be a peak when current is increased or may be a valley (a dip, a local depression) when the current is decreased.
  • the fuel crossover rate can suddenly increase to a peak ( Figure 3) before settling to a new lower value.
  • the fuel crossover rate can suddenly decrease to a valley, before settling to a new higher value ( Figure 3).
  • the first transient fuel crossover rate or the second transient fuel crossover rate can be determined by measuring a peak value of transient fuel crossover as the fuel crossover rate is decreased, or by measuring a trough value of transient fuel crossover as the fuel crossover rate is increased.
  • the transient fuel crossover rate can be measured by measuring CO 2 concentration at the cathode side of the fuel cell
  • I i5 I 2 and I 3 are positive values denoting the regular flow of current from a fuel cell. Further, I 1 , I 2 and I 3 may be each less than I max , the maximal current through the fuel " cell. As other examples, the relationship between I 1 , 1 2 and I 3 may be I 2 ⁇ Ii ⁇ I 3 ; or I] ⁇ I 2 ⁇ I 3 ; or I 3 ⁇ I
  • I], I 2 and I3 are at least 10% apart. That is, for example, if I[ is 100, 1 2 and I 3 should be greater than or equal 110 or less than or equal to 90. Furthermore, if I 2 is 110, I 3 should be greater than or equal to 121, or less than or equal to 90 (so I 3 is at least 10% apart from both I 2 and I] .). Tn another preferred embodiment, I 5 , I 2 and I 3 are at least 20%, 30%, 40% 50% 75% or 100% apart. As another example Ij, I 2 and I 3 at 100% apart could have values of 50, 100, and 200.
  • the electrochemical device may be a fuel cell.
  • the fuel cell may comprise an anode catalyst layer, a cathode catalyst layer, and at least one layer of electrolyte.
  • the electrolyte can be a liquid electrolyte, an electrolyte membrane, or a solid electrolyte.
  • the interface fuel concentration to be measured may be a concentration of fuel (reactant) between the anode catalyst layer and the electrolyte.
  • the fuel cell can comprise an anode diffusion layer, a cathode diffusion layer or both.
  • the fuel cells that are susceptible to the measurement methods of the invention may be a liquid fuel cell.
  • the fuel cell can be a polymer electrolyte membrane fuel cell, a phosphoric acid fuel cell, a direct methanol fuel cell, an alkaline fuel cell, a solid oxide fuel cell or a molten carbonate fuel cell.
  • the fuel cell may use an organic fuel - such as, for example, methanol for a direct methanol fuel cell DMFC. If a DMFC is measured, the interface fuel concentration is an interface methanol concentration, and the drag coefficient is a methanol drag coefficient.
  • the fuel cell being measure has the same pressure on an anode side and on a cathode side.
  • the apparatus may comprise (a) means for measuring a transient fuel crossover rate in the fuel cell; (b) means for measuring a current density of the fuel cell; and (c) means for changing a current density ' of the fuel cell in a stepwise fashion between I;, and I3, and between I 2 and I 3 .
  • Part (a) can be a CO 2 detector on the cathode side of the fuel cell to determine CO2 percentage and a flow meter to determine total gas per unit time.
  • Part (b) can be an amp meter, a voltmeter or any electronic device that can measure electric current.
  • Part (c) can be a load bank, a voltage controller, or a power supply. It Is preferred that part (c) be capable of switching the current density quickly - that is, the current density should change as close to a step function as possible.
  • the apparatus may further comprise a processor, such as a computer or dedicated detector, adapted to receive the signals from the means for measuring a transient fuel crossover rate and the means for measuring a current density. Based on these inputs, the processor should calculate the interface fuel concentration or the fuel drag coefficient.
  • the apparatus can monitor the interface reactant concentration (e.g., interface methanol concentration). For example, if the interface reactant concentration is at an undesirable level, operating parameters may be adjusted to bring the concentration back to an acceptable level. Adjustments may involve using auxiliary power from a generator or battery, stopping the fuel cell, increasing or reducing the load - for example, by adding or removing fuel cells - or other types of adjustments and changing the fuel concentration.
  • the interface reactant concentration e.g., interface methanol concentration
  • a direct methanol fuel cell may be used for any of the embodiments and aspects of this disclosure.
  • Any fuel feedstock may be used such as for example, methanol at concentrations of 0.5 M to 5M. However ranges of methanol above and below these values are also applicable.
  • the fuel is one of the reactants.
  • Figure 1 depicts a schematic of experimental system.
  • Figure 2 depicts a schematic of peaks for transient methanol crossover measurement
  • Figure 3 depicts methanol crossover peaks at transient states: methanol concentration 0.5M; methanol flow rate, 3 mlmin ""1 ; air flow rate, 800 seem.
  • Figure 4 depicts methanol crossover peaks at transient states: methanol concentration IM; methanol flow rate, 3 mlmixT 1 ; air flow rate, 800 seem.
  • Figure 5 depicts methanol crossover peaks at transient states: methanol concentration 2M; methanol flow rate, 3 ml mkf ! ; air flow rate, 800 seem.
  • Figure 6 depicts methanol crossover peaks at transient states: methanol concentration 3M; methanol flow rate, 3 mlmin "1 ; air flow rate, 1600 seem.
  • Figure 7 depicts methanol crossover peaks at transient states: methanol concentration 0.5M; methanol flow rate, 3 mlmin "1 ; air flow rate, 1600 seem.
  • Figure S depicts methanol drag coefficient versus methanol concentration at the interface between the anode catalyst layer and electrolyte polymer membrane (linear model).
  • Figure 9 depicts methanol drag coefficient versus methanol concentration at the interface between the anode catalyst layer and electrolyte polymer membrane (Weibull Model)
  • Figure 10 depicts the effects of the cell voltage and methanol feeding concentration on the total amount of methanol crossover and the amount of methanol crossover caused by the diffusion and electro-osmosis drag: no cathode humidification; methanol concentration 0.5-5M; methanol flow rate, 3 mlmin "1 , air stoichiometric is greater than 40.
  • Figure 11 depicts the effects of methanol feeding concentration on the total methanol crossover and the amount of methanol crossover caused by the diffusion and osmosis drag: methanol concentration 0.5-5M; methanol flow rate, 3 mlmin ""1 , air stoichiometric is greater than 40, Cell voltage is at V max .
  • Figure 12 depicts the effects of methanol feeding concentration on the total methanol crossover and the amount of methanol crossover caused by the diffusion and osmosis drag: methanol concentration 0.5-5M; methanol flow rate, 3 mimirf 1 , air stoichiometric is greater than 40, Cell voltage is at 0.394V.
  • Figure 13 depicts the effects of methanol feeding concentration on the total methanol crossover and the amount of methanol crossover caused by the diffusion and osmosis drag: methanol concentration 0.5-5M; methanol flow rate, 3 rnlmiiT 1 , air stoichiometric is greater than 40, Cell voltage is at 0.096V.
  • the experimental system is schematically shown in Figure 1.
  • the fuel cell test station was manufactured by Fuel Cell Technology, Inc.
  • a major component of the test station is the HP ® 6050A system DC electronic load controller, which is capable of controlling the electrical, load on the fuel cell as well as measuring its voltage versus current responses.
  • This experimental system also provides control over anode and cathode flow rates, cell operating temperature, operating pressure, and humidification temperature for the cathode.
  • the cathode mass flow rate is controlled and measured by a MKS ® mass flow controller, and the anode flow rate is controlled and measured by a peristaltic pump by Gilson, Inc.
  • the experimental fuel cell consists of two 316 stainless steel end plates, two graphite collector plates with machined serpentine flow fields, two carbon cloth diffusion layers, two catalyst layers and an electrolyte polymer membrane.
  • the cell was kept at a constant temperature through the thermal management system during each experiment.
  • the membrane used was National® 117; the gas diffusion layers on the anode side is carbon cloth and ETEK ELAT® on the cathode side;
  • the catalyst was Pt-Ru on the anode side with a loading of 4 mg cm ""2 ; and the catalyst was Pt-black on the cathode side with a loading of 4 mg cm "2 .
  • the total active area of the cell was 5 cm 2 .
  • the carbon dioxide sensor used in this test was GMP221 Carbon dioxide probe from Vaisala Oyj, Finland. When methanol reaches the cathode side, most reacts with oxygen and turns into CO 2 , and only a very small amount becomes the intermediate products CH x 0 y and
  • the concentration of water vapor at the cathode exit is a constant for each experiment since the temperature is held constant and the cathode exhaust is saturated.
  • the method of using a carbon dioxide sensor to detect the amount of methanol cross-over is of sufficient accuracy for the measurements of this disclosure. In addition, it is very convenient and is capable of real time monitoring of methanol crossover as the measurements and experiments are conducted.
  • a fuel cell is understood to behave regularly - that is, when voltage is increased when current is decreased, voltage in decreased when current is increased, the maximum voltage (Vmax) occurs when the current is at the minimum and the minimum voltage (V m i n ) occurs when the current is at its maximum.
  • Vmax maximum voltage
  • V m i n minimum voltage
  • the amounts of methanol crossover flux derived by all of these three affecters depend directly on the methanol concentration at the interface between the anode catalyst layer and the Nafion ® electrolyte polymer membrane.
  • the fuel concentration i.e., reactant concentration in a fuel cell, methanol concentration in a DMTC
  • the amount of fuel crossover can be calculated using the methods of the invention.
  • the rate of the methanol concentration changing at this interface is much slower than the rate of cell current change when a cell voltage changes abruptly.
  • transient state 1 represents the state when the cell voltage changes from Vmax to 0.394V
  • transient state 2 represents the state when the cell voltage changes from 0.394V Io 0.096V
  • transient state 3 represents the state when the cell voltage changes from 0.096V to 0.394V
  • transient state 4 represents the state when the cell voltage changes from 0.394V to V maj£ ; where V max is the maximum cell closed circuit voltage where the cell current density is 0.002A/cm2.
  • DMFC and methanol concentrations have been used as an example. However, it should be understood that the general principal, the methods, the apparatus and the fuel cells of the invention is applicable to all fuel cells types.
  • Figure 3 shows that there are four peaks in methanol crossover corresponding to the four transition states when cell voltage is changed abruptly.
  • the first peak is related to the cell voltage changes from V max to 0.394V;
  • the second peak is related to the cell voltage changes from 0.394V to 0.096V;
  • the third peak is related to the cell voltage changes from 0.096V back to 0.394V;
  • the fourth peak is related to the cell voltage changes from 0.394V back to V max .
  • Example 3 Derivation of the Formula and Explanation of the Method in General
  • the first equation is to show the methanol crossover flux j includes two parts, the diffusion part and the electronic drag part. Note that "n" is removed in the second term. This is due to fact that n is always equal to 1.
  • this equation contains two unknowns, Ci and ⁇ m .
  • X is the measured valued using a CO 2 sensor at the cathode exit and the rest are all constants.
  • a current as small as 0.002 A/cm 2 in the cell current changes the interface methanol concentration drastically than an open circuit.
  • Methanol crossover decreases at lower voltage when the methanol feeding concentration is low; on the contrary, it increases when methanol feeding concentration is high.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Fuel Cell (AREA)

Abstract

L'invention concerne un procédé de mesure pour déterminer la concentration de combustible d'interface et/ou le coefficient de traînée d'une pile à combustible à I1 sur la base de la mesure du taux de croisement de combustible transitoire et de la densité de courant après changement lorsque le courant de la pile à combustible est brusquement modifié (1) de I1 à I2 et (2) de I1 à I3, I1, I2 et I3 ayant chacun une valeur différente. La densité de courant après changement est (a) la densité de courant à I2 après la transition de I1 à I2 ou (2) la densité de courant à I3 après la transition de I1 à I3. Lorsque la pile à combustible est une pile à combustible directe de méthanol (DMFC), la concentration de combustible d'interface est le méthanol d'interface et le coefficient de traînée est le coefficient de traînée de méthanol.
PCT/US2008/069203 2007-07-03 2008-07-03 Procédé et appareil de mesure de concentration de réactif d'interface dans un dispositif électrochimique Ceased WO2009006594A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92955507P 2007-07-03 2007-07-03
US60/929,555 2007-07-03

Publications (1)

Publication Number Publication Date
WO2009006594A1 true WO2009006594A1 (fr) 2009-01-08

Family

ID=40226546

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2008/069203 Ceased WO2009006594A1 (fr) 2007-07-03 2008-07-03 Procédé et appareil de mesure de concentration de réactif d'interface dans un dispositif électrochimique

Country Status (1)

Country Link
WO (1) WO2009006594A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102759671A (zh) * 2011-04-26 2012-10-31 通用汽车环球科技运作有限责任公司 质子交换膜燃料电池膜健康随其寿命的原位量化算法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6444343B1 (en) * 1996-11-18 2002-09-03 University Of Southern California Polymer electrolyte membranes for use in fuel cells
US6596422B2 (en) * 1999-12-17 2003-07-22 The Regents Of The University Of California Air breathing direct methanol fuel cell
US20040028977A1 (en) * 2000-05-30 2004-02-12 Peter Pickup Fuel cell incorporating a modified ion exchange membrane
US6991865B2 (en) * 2000-11-22 2006-01-31 Mti Microfuel Cells Inc. Apparatus and methods for sensor-less optimization of methanol concentration in a direct methanol fuel cell system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6444343B1 (en) * 1996-11-18 2002-09-03 University Of Southern California Polymer electrolyte membranes for use in fuel cells
US6596422B2 (en) * 1999-12-17 2003-07-22 The Regents Of The University Of California Air breathing direct methanol fuel cell
US20040028977A1 (en) * 2000-05-30 2004-02-12 Peter Pickup Fuel cell incorporating a modified ion exchange membrane
US6991865B2 (en) * 2000-11-22 2006-01-31 Mti Microfuel Cells Inc. Apparatus and methods for sensor-less optimization of methanol concentration in a direct methanol fuel cell system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102759671A (zh) * 2011-04-26 2012-10-31 通用汽车环球科技运作有限责任公司 质子交换膜燃料电池膜健康随其寿命的原位量化算法

Similar Documents

Publication Publication Date Title
Zhang et al. PEM fuel cell relative humidity (RH) and its effect on performance at high temperatures
Houser et al. Architecture for improved mass transport and system performance in redox flow batteries
Xia et al. The application of orthogonal test method in the parameters optimization of PEMFC under steady working condition
Milewski et al. Modeling the performance of MCFC for various fuel and oxidant compositions
Han et al. Electrochemical performance modeling of a proton exchange membrane electrolyzer cell for hydrogen energy
Niya et al. Study of proton exchange membrane fuel cells using electrochemical impedance spectroscopy technique–A review
Shamardina et al. A simple model of a high temperature PEM fuel cell
Liu et al. Optimization of PEM fuel cell flow channel dimensions—Mathematic modeling analysis and experimental verification
Liu et al. In situ potential distribution measurement in an all-vanadium flow battery
Milewski et al. A reduced order model of molten carbonate fuel cell: A proposal
Reshetenko et al. Effects of local variations of the gas diffusion layer properties on PEMFC performance using a segmented cell system
Al Shakhshir et al. In-situ experimental characterization of the clamping pressure effects on low temperature polymer electrolyte membrane electrolysis
Rodat et al. EIS measurements in the diagnosis of the environment within a PEMFC stack
Ferng et al. Parametric investigation to enhance the performance of a PBI-based high-temperature PEMFC
Schaffer et al. Determination of methanol diffusion and electroosmotic drag coefficients in proton-exchange-membranes for DMFC
Steffy et al. Online monitoring of fuel starvation and water management in an operating polymer electrolyte membrane fuel cell by a novel diagnostic tool based on total harmonic distortion analysis
Najjari et al. The effects of the gravity on transient responses and cathode flooding in a proton exchange membrane fuel cell
Park et al. An experimental investigation of electro-osmotic drag coefficients in a polymer electrolyte membrane fuel cell
Wasterlain et al. Study of temperature, air dew point temperature and reactant flow effects on proton exchange membrane fuel cell performances using electrochemical spectroscopy and voltammetry techniques
Elden et al. The effects of temperature on transport phenomena in phosphoric acid doped polybenzimidazole polymer electrolyte membrane fuel cell
Darowicki et al. The influence of dynamic load changes on temporary impedance in hydrogen fuel cells, selection and validation of the electrical equivalent circuit
Li et al. Select sensitivity parameters for proton exchange membrane fuel cell model: An identification method from analytical Butler-Volmer equation
Sohn et al. Numerical analysis on water transport in alkaline anion exchange membrane fuel cells
Clement et al. Measurement of localized current distribution in a vanadium redox flow battery
Li et al. Membrane water-flow rate in electrolyzer cells with a solid polymer electrolyte (SPE)

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08826028

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08826028

Country of ref document: EP

Kind code of ref document: A1