CN111471939A - High Ni stainless steel suitable for proton exchange membrane fuel cell bipolar plate - Google Patents

High Ni stainless steel suitable for proton exchange membrane fuel cell bipolar plate Download PDF

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Publication number
CN111471939A
CN111471939A CN202010272916.8A CN202010272916A CN111471939A CN 111471939 A CN111471939 A CN 111471939A CN 202010272916 A CN202010272916 A CN 202010272916A CN 111471939 A CN111471939 A CN 111471939A
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China
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stainless steel
fuel cell
bipolar plate
exchange membrane
proton exchange
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CN202010272916.8A
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Chinese (zh)
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黄一川
王清
吴爱民
林国强
董闯
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Dalian University of Technology
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Dalian University of Technology
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
    • C23C22/50—Treatment of iron or alloys based thereon
    • 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
    • H01M8/02—Details
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/0204—Non-porous and characterised by the material
    • H01M8/0206—Metals or alloys
    • H01M8/0208—Alloys
    • H01M8/021—Alloys based on iron
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • 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

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Electrochemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Fuel Cell (AREA)

Abstract

The invention discloses a high-Ni stainless steel suitable for a bipolar plate of a proton exchange membrane fuel cell, belonging to the technical field of new materials, and the high-Ni stainless steel determines that the ideal components of a stainless steel material suitable for a bipolar plate substrate of the fuel cell comprise 19-21% of Ni, 16.5-18.5% of Cr, less than 0.5% of the total amount of inevitable impurities and the balance of Fe. according to the performance indexes of 0.5 mol/L H2SO4In +2ppm environment, the self-corrosion potential is as high as-224.98 mV, and the self-corrosion current density IcorrDown to 1.68. mu.A/cm20.064MPa with carbon paperContact resistance of 0.99. omega. cm2. It is possible to realize excellent corrosion resistance and electrical conductivity and excellent low contact resistance with the gas diffusion layer, and to impart excellent quality and durability to the fuel cell.

Description

High Ni stainless steel suitable for proton exchange membrane fuel cell bipolar plate
Technical Field
The invention belongs to the technical field of new materials, relates to components of a novel Fe-Cr-Ni austenitic stainless steel, and relates to a fuel cell bipolar plate material application technology in the technical field of new energy.
Background
Metallic materials are often used for electrical applications, one of which is proton exchange membrane fuel cell bipolar plates. A Proton Exchange Membrane Fuel Cell (PEMFC) is a clean and pollution-free power generation device that directly converts chemical energy in a fuel and an oxidant into electric energy using hydrogen as the fuel and oxygen/air as the oxidant, and thus it is expected to introduce and popularize the fuel cell in terms of energy saving and environmental protection measures. The bipolar plate is used as one of the key components of the proton exchange membrane fuel cell, the weight of the bipolar plate accounts for 70-80% of the total weight of the electric pile, and the production cost accounts for more than 46% of the total cost of the fuel cell. The quality of the fuel cell stack determines the output power of the fuel cell stack and the service life length.
The bipolar plate substrate material has the function of providing a circulating flow field for fuel gas or oxidizing gas and discharging water produced at the cathode side to ensure effective discharge from the cell to the outside of the system. In addition, it must support the cells to keep the stack structurally stable, separate the anode compartment from the cathode compartment of the adjacent cell, collect the conduction current, and contact the gas diffusion layers (anode, cathode) to form an electrical path that serves as an electrical "connector" between two adjacent cells. Therefore, the fuel cell bipolar plate must have electrochemical stability in an acidic fuel cell environment, must have good mechanical properties, must have as low contact resistance as possible with graphite, and must have high corrosion resistance.
The metal alloy, especially the bipolar plate made of stainless steel material, is considered to have the advantages of excellent processing performance, and the thickness (100-300 μm) of the separator can be reduced, thereby reducing the weight of the separator, greatly improving the specific power of the stack, and being the most competitive substrate material. The stainless steel has the advantages of easy processing and forming, high thermal conductivity, low price and the like, so that the stainless steel becomes a base material of a bipolar plate of a proton exchange membrane fuel cell which is commonly used. Stainless steel has a high resistivity and, in addition, the additional resistivity of the oxide products on the surface in service reduces the conductivity of the stainless steel in contact with the gas diffusion layer, and therefore surface modification is often used to overcome this problem. However, the surface modification method has a complex process, and the surface treatment layer is also easily damaged due to physical factors, so that the method has higher requirements on the comprehensive performance of the matrix material, and the method becomes more important for obtaining better service performance by optimizing the components of the matrix material.
A literature search of the prior art shows that (Davies et al) published on Journal of Power sources (237-, resulting in a change in its electrical conductivity, with the general tendency that the interfacial resistivity of stainless steel alloys decreases with increasing nickel content.
Therefore, it is a problem to be solved to find a high Ni stainless steel composition having excellent conductivity suitable for the working environment of the fuel cell bipolar plate using an effective alloy design method.
Disclosure of Invention
The invention aims to provide a novel austenitic stainless steel suitable for a base material of a bipolar plate of a proton exchange membrane fuel cell, and the alloy can replace the existing stainless steel such as 316L and the like, so that the bipolar plate has composite properties such as corrosion resistance, electric conduction and the like, and meets the requirement of long-term service in the proton exchange membrane fuel cell as the base material.
The high-Ni stainless steel suitable for the bipolar plate of the proton exchange membrane fuel cell comprises elements Fe, Cr and Ni, wherein the high-Ni stainless steel comprises 19-21 mass percent of Ni, 16.5-18.5 mass percent of Cr, less than 0.5 mass percent of inevitable impurities and the balance of Fe.
The invention determines an ideal component of stainless steel suitable for a fuel cell bipolar plate matrix by a design method of cluster and connecting atoms, selects the Cr content similar to that of a 316L reference alloy according to the effects of austenite stabilization and corrosion resistance improvement of Ni under a component frame given by a model, implements preparation and performance tests of alloys with different Ni contents, finds that the corrosion resistance and the conductivity of an alloy passive film are synchronously improved along with the Ni content, the Ni content is optimal when the Ni content is 20%, when the Ni content is lower than the optimal value, the corrosion resistance and the conductivity are only slightly better than those of 316L stainless steel, the Ni content exceeds 20%, the corrosion resistance and the conductivity are not obvious, and therefore, the components of the stainless steel with optimized components have the following characteristics that the mass percentage composition of the stainless steel is 19-21% of Ni, 16.5-18.5% of Cr, the balance of Fe and inevitable impurities, the total amount of the impurities is less than 0.5%, compared with the traditional austenitic stainless steel grade, the formula components have the following uniqueness that 1) do not contain metallurgical residual elements such as C, Si, Mn and the like, 2) belong to high-purity alloys, 3) the components of the stainless steel, the components of the stainless steel and the components of the stainless steel reach the proper content of Cr, the common stainless steel, the content of the existing stainless steel, the invention is developed and the invention, the invention is consistent with the existing stainless steel.
Compared with the 316L stainless steel used for manufacturing the bipolar plate at present, the invention has the advantages and the characteristics that the 316L stainless steel contains less impurity elements and is in the service environment of the bipolar plate (0.5 mol/L H)2SO4+2ppm HF) has more excellent properties. After nitric acid passivation treatment, self-decayingEtching potential EcorrUp to-224.98 mV, self-corrosion current density IcorrDown to 1.68. mu.A/cm2Is superior to the corrosion resistance (E) of 316L stainless steelcorrAnd IcorrRespectively is-264.47 mV and 7.51 muA/cm2) And the ICR of the contact resistance with the carbon paper at 0.064MPa is as low as 0.99 omega cm2ICR (1.1. omega. cm) of less than 316L stainless steel2)。
The invention has the effects and benefits that ① develops a new austenitic stainless steel suitable for a fuel cell bipolar plate base material, the components of high Ni and proper Cr content are accurately determined, the mass percentage (wt.%) of the alloy components is 19-21% of Ni, 16-18% of Cr, less than 0.5% of impurities and the balance of Fe, no elements such as C, N, Si are contained in the alloy, the smelting process is simple, pure material smelting is adopted, the ② alloy has good corrosion resistance and low contact resistance, and can replace stainless steel such as 316L and the like to serve as a novel bipolar plate base material with better performance.
Drawings
FIG. 1 is a schematic representation of the polarization curve of 316L stainless steel and example 1 passivated in a simulated fuel cell bipolar plate operating environment with current density on the abscissa and in A/cm2The graph shows that in the simulated fuel cell operating environment, the self-corrosion potential of example 1 is-224.98 mV, which is higher than the self-corrosion potential (-264.47mV) of 316L stainless steel, indicating a lower tendency to thermodynamic corrosion, the self-corrosion current density of 539316 316 stainless steel is 7.51 muA/cm2The self-etching current density of example 1 was 1.68. mu.A/cm2And is lower than that.
FIG. 2 is a graphical representation of the contact resistance at 0.064MPa for 316L stainless steel and example 1 after passivation, on the abscissa the Ni equivalent in wt.%, and on the ordinate the contact resistance ICR in Ω cm2. As can be seen, the ICR of example 1 was 0.99. omega. cm2ICR (1.1. omega. cm) of 316L stainless steel2) And lower.
Detailed Description
The following describes the embodiments of the present invention in detail with reference to the technical solutions.
The novel stainless steel material suitable for the base material of the bipolar plate of the proton exchange membrane fuel cell has accurate high Ni and proper Cr content, and comprises, by mass, 19-21% of Ni, 16.5-18.5% of Cr, and the balance of Fe and inevitable impurities. The surface of the film is a passivation film of more than 1-10 nm of element oxide.
Example 1: fe62.71Ni19.77Cr17.52(wt.%) alloy
The method comprises the following steps: alloy preparation
A high-Ni stainless steel suitable for the bipolar plate of proton exchange membrane fuel cell is prepared from high-purity component (Fe)62.71Ni19.77Cr17.52(wt.%). Placing 26g of the mixture into a water-cooled copper crucible of an arc melting furnace, melting under the protection of argon atmosphere by adopting a non-consumable arc melting method, and repeatedly melting for at least 5 times to obtain an alloy ingot with uniform components; and melting the uniformly melted alloy ingot, and sucking the melt into a cylindrical copper mold cavity by using a copper mold suction casting process to obtain a bar with the diameter of 10 mm.
Step two: making a heat treatment system
The heat treatment system comprises the temperature and the time length of solution treatment, and the heat treatment system is set to be 1423K for solution treatment for 2h and then is quickly taken out for water cooling. Based on this, the alloy is heat-treated.
Step three: alloy structure in solid solution state
The OM and XRD are utilized to detect the alloy structure and structure after the water cooling of the solution treatment, and the result shows that the alloy structure of the invention is single-phase austenite.
Step four: passivation treatment
The sample is first degreased by shaking with acetone for 12min and then soaked in 10 wt.% of H2SO4Activating with acid for 5min, and soaking in passivation solution (20 wt.% HNO)3Solution) for 60 min.
Step five: corrosion resistance and contact resistance test
Testing of potentiodynamic polarization curves, self-corrosion potential E, by means of an electrochemical workstationcorr-224.98mV, self-corrosion current density Icorr＝1.68μA/cm2. The contact resistance with the carbon paper is tested by voltammetry, and the contact resistance ICR under 0.064MPa is 0.99 omega cm2。

Claims (1)

1. The high-Ni stainless steel suitable for the bipolar plate of the proton exchange membrane fuel cell is characterized in that the components of the high-Ni stainless steel suitable for the bipolar plate of the proton exchange membrane fuel cell comprise 19-21% of Ni, 16.5-18.5% of Cr, less than 0.5% of unavoidable impurities and the balance of Fe by mass percent.
CN202010272916.8A 2020-04-09 2020-04-09 High Ni stainless steel suitable for proton exchange membrane fuel cell bipolar plate Pending CN111471939A (en)

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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2337223A (en) * 1998-05-15 1999-11-17 Bondface Technology Inc Bonding of metal workpieces
CN1864294A (en) * 2003-10-14 2006-11-15 纽韦拉燃料电池欧洲有限责任公司 Electrochemical generator
CN101694879A (en) * 2009-10-22 2010-04-14 大连海事大学 Mo-nitride-containing surface modification fuel cell stainless steel bipolar plate and manufacturing method thereof
CN101710621A (en) * 2009-12-11 2010-05-19 江苏新源动力有限公司 Proton exchange membrane fuel cell stainless steel bipolar plate and method for preparing same
CN102324528A (en) * 2011-09-21 2012-01-18 大连海事大学 Surface-modified fuel cell stainless steel bipolar plate with Nb nitride and manufacturing method thereof
CN102623720A (en) * 2012-04-01 2012-08-01 大连海事大学 Fuel cell metal bipolar plate containing tungsten-modified layer and manufacture method thereof
KR20140082506A (en) * 2012-12-24 2014-07-02 주식회사 포스코 Method for manufacturing pemfc bipolar plate
CN106684394A (en) * 2015-11-06 2017-05-17 中国科学院大连化学物理研究所 Surface modification method of proton-exchange membrane fuel cells' stainless steel bipolar plates
CN107146899A (en) * 2016-03-01 2017-09-08 中国科学院大连化学物理研究所 Proton exchange membrane fuel cell stainless steel bipolar plate face coat structure and preparation
JP2018507510A (en) * 2015-01-21 2018-03-15 イーシー パワー，エルエルシー Self-heating fuel cell system

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2337223A (en) * 1998-05-15 1999-11-17 Bondface Technology Inc Bonding of metal workpieces
CN1864294A (en) * 2003-10-14 2006-11-15 纽韦拉燃料电池欧洲有限责任公司 Electrochemical generator
CN101694879A (en) * 2009-10-22 2010-04-14 大连海事大学 Mo-nitride-containing surface modification fuel cell stainless steel bipolar plate and manufacturing method thereof
CN101710621A (en) * 2009-12-11 2010-05-19 江苏新源动力有限公司 Proton exchange membrane fuel cell stainless steel bipolar plate and method for preparing same
CN102324528A (en) * 2011-09-21 2012-01-18 大连海事大学 Surface-modified fuel cell stainless steel bipolar plate with Nb nitride and manufacturing method thereof
CN102623720A (en) * 2012-04-01 2012-08-01 大连海事大学 Fuel cell metal bipolar plate containing tungsten-modified layer and manufacture method thereof
KR20140082506A (en) * 2012-12-24 2014-07-02 주식회사 포스코 Method for manufacturing pemfc bipolar plate
JP2018507510A (en) * 2015-01-21 2018-03-15 イーシー パワー，エルエルシー Self-heating fuel cell system
CN106684394A (en) * 2015-11-06 2017-05-17 中国科学院大连化学物理研究所 Surface modification method of proton-exchange membrane fuel cells' stainless steel bipolar plates
CN107146899A (en) * 2016-03-01 2017-09-08 中国科学院大连化学物理研究所 Proton exchange membrane fuel cell stainless steel bipolar plate face coat structure and preparation

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