Titanium fibrofelt composite material and PEM electrolytic tank comprising same

Abstract

The invention discloses a titanium fibrofelt composite material and a PEM electrolytic tank containing the titanium fibrofelt composite material, and relates to the technical field of PEM electrolytic tanks. The titanium powder mixture layer is arranged on the second surface of the titanium fibrofelt base material layer, and the particle size and mass ratio of large-particle titanium powder to small-particle titanium powder in the titanium powder mixture layer and the porosity and the average pore size of the titanium fibrofelt base material layer are controlled to be within a proper range, so that the titanium powder mixture layer has a pore structure with proper pore size and pore size distribution; and when the obtained titanium fiber felt composite material is used as an anode gas diffusion layer of a PEM electrolytic tank, the cooperative transmission effect of water and oxygen is good, the mass transfer loss in the operation process of the electrolytic tank is low, and the internal temperature of the electrolytic tank is easy to control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PEM electrolytic cell, and particularly relates to a titanium fiber felt composite material and a PEM electrolytic cell containing the same. BACKGROUND

[0002] Proton exchange membrane (PEM) electrolytic cell has become one of the core technologies for hydrogen energy preparation due to high energy conversion efficiency and fast response capability. The anode gas diffusion layer as a key component for realizing water gas transmission and electrochemical reaction directly affects the efficiency and stability of the PEM electrolytic cell. However, the traditional anode gas diffusion layer has poor water and oxygen co-transport effect, high mass transfer loss and high internal temperature rise of the electrolytic cell.

[0003] Therefore, it is necessary to develop a technology to solve the above technical problems existing in the anode gas diffusion layer. SUMMARY

[0004] The present application aims to overcome the deficiencies of the prior art and provide a titanium fiber felt composite material and a PEM electrolytic cell containing the same. The titanium fiber felt composite material is used as an anode gas diffusion layer, has good water and oxygen co-transport effect, low mass transfer loss during electrolytic cell operation and easy control of the internal temperature of the electrolytic cell.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a titanium fiber felt composite material, comprising:

[0006] a titanium fiber felt substrate layer having a first surface and a second surface arranged oppositely;

[0007] a titanium powder mixture layer located on the second surface of the titanium fiber felt substrate layer;

[0008] wherein the titanium powder mixture layer contains large particle titanium powder and small particle titanium powder, the mass ratio of the small particle titanium powder to the large particle titanium powder is 3:7-1:1, the particle size of the large particle titanium powder is in the range of 15-50 μm, and the particle size of the small particle titanium powder is below 5.5 μm;

[0009] The porosity of the titanium fiber felt substrate layer is 50%-70%, and the average pore size is 30-60 μm.

[0010] In a third aspect, the present application provides a PEM electrolytic cell comprising an anode gas diffusion layer, wherein the anode gas diffusion layer comprises the titanium fiber felt composite material.

[0011] Compared with the prior art, the application has the beneficial effects that: by setting a titanium powder mixture layer on the second surface of the titanium fiber felt substrate layer, and controlling the particle size and mass ratio of the large and small particle titanium powders in the titanium powder mixture layer and the porosity and average pore size of the titanium fiber felt substrate layer within a suitable range, the titanium powder mixture layer has a pore structure with a suitable pore size and pore size distribution, and when the obtained titanium fiber felt composite material is used as the anode gas diffusion layer of a PEM electrolytic cell, the synergistic transmission effect of water and oxygen is good, the mass transfer loss during the operation of the electrolytic cell is low, and the internal temperature of the electrolytic cell is easy to control. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 Figure 1 is a structural schematic diagram of the titanium fiber felt composite material of the application, wherein 11 is a titanium fiber felt substrate layer, 111 is a first surface, 112 is a second surface, 12 is a titanium powder mixture layer, 121 is large particle titanium powder, and 122 is small particle titanium powder. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0014] In the application, the open technical features include the closed technical scheme composed of the listed features, and also include the open technical scheme containing the listed features.

[0015] In the application, if no special description is provided, the numerical range is regarded as continuous and includes the minimum value and the maximum value of the range and each value between the minimum value and the maximum value. Further, when the range refers to an integer, each integer between the minimum value and the maximum value of the range is included. In addition, when multiple ranges are provided to describe a feature or a characteristic, the ranges can be combined. In other words, unless otherwise specified, all the ranges disclosed herein should be understood as including any and all sub-ranges falling within the range.

[0016] In the application, the specific dispersion and stirring treatment method is not particularly limited.

[0017] The reagents or instruments used in the application are not specified by the manufacturer, and are conventional products that can be obtained by purchase.

[0018] REFERENCE Figure 1 According to a first aspect of the application, a titanium fiber felt composite material is provided, comprising:

[0019] A titanium fiber felt substrate layer 11 has a first surface 111 and a second surface 112 arranged oppositely;

[0020] A titanium powder mixture layer 12 is arranged on the second surface 112 of the titanium fiber felt substrate layer 11.

[0021] The titanium powder mixture layer 12 contains large-particle titanium powder 121 and small-particle titanium powder 122, and the mass ratio of the small-particle titanium powder 122 to the large-particle titanium powder 121 is 3:7-1:1, the particle size of the large-particle titanium powder 121 is in the range of 15-50 μm, and the particle size of the small-particle titanium powder 122 is less than 5.5 μm.

[0022] The porosity of the titanium fiber felt substrate layer 11 is 50%-70%, and the average pore size is 30-60 μm.

[0023] The titanium fiber felt composite material has the titanium powder mixture layer 12 arranged on the second surface 112 of the titanium fiber felt substrate layer 11 with a specific porosity and average pore size, and the titanium powder mixture layer 12 has small pore sizes (<5 μm), medium pore sizes (5-20 μm), and large pore sizes (>20 μm) by using the large-particle titanium powder 121 and the small-particle titanium powder 122 with a specific ratio and a specific particle size range, the small pore sizes can promote the transmission of water by capillary action, the medium pore sizes can transmit both water and oxygen, and the large pore sizes can relieve the water blockage of the pores and facilitate the smooth transmission of oxygen. Under the action of the titanium powder mixture layer 12, when the titanium fiber felt composite material is used as the anode gas diffusion layer of the PEM electrolytic cell, the water and oxygen have a good synergistic transmission effect, the mass transfer loss is low during the operation of the electrolytic cell, and the internal temperature of the electrolytic cell is easy to control.

[0024] The mass ratio of the large-particle titanium powder 121 to the small-particle titanium powder 122 needs to be controlled in the range of 3:7-1:1, such as 3:7, 3.5:6.5, 4:6, 4.5:5.5, 1:1, or an interval range formed by any two of the above values, which can reduce the risk of the titanium powder mixture layer collapsing into the pores of the titanium fiber felt substrate layer 11 under stress and ensure that the titanium powder mixture layer can form pores with small, medium, and large pore sizes, thereby laying a foundation for the synergistic transmission of water and oxygen.

[0025] The particle size of the large-particle titanium powder 121 is in the range of 15-50 μm, and the particle size of the small-particle titanium powder 122 is in the range of 4-5 μm, so that the titanium powder mixture layer 12 can not only form pores with small, medium, and large pore sizes, but also have a more suitable pore size distribution, thereby laying a foundation for the synergistic transmission of water and oxygen. The particle size of the large-particle titanium powder 121 can be selected as 15-45 μm, 15-40 μm, 16-35 μm, or 20-30 μm, etc. The particle size of the small-particle titanium powder 122 can be selected as 5-4.1 μm or 4.8-4.5 μm, etc.

[0026] The porosity of the titanium fiber felt substrate layer 11 is 50% to 70%, and the average pore size is 30 to 60 μm, so that not only can the collapse of the titanium powder mixture layer 12 into the pores of the titanium fiber felt substrate layer 11 when the titanium powder mixture layer 12 is stressed be alleviated, but also the pore size and pore size distribution of the pore structure inside the titanium powder mixture layer 12 are more suitable, the synergistic transport effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, and the internal temperature of the electrolytic cell is easier to control. For example, the porosity of the titanium fiber felt substrate layer 11 is 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, or an interval range formed by any two of the above values. For example, the average pore size of the titanium fiber felt substrate layer 11 is 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, or an interval range formed by any two of the above values.

[0027] In some embodiments, the particle size of the large particle titanium powder 121 is 21.2 to 30 μm. When the particle size of the large particle titanium powder 121 is within this range, the pore structure size and its distribution inside the titanium powder mixture layer are more suitable, the synergistic transport effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, and the internal temperature of the electrolytic cell is easier to control.

[0028] In some embodiments, the particle size of the small particle titanium powder 122 is 3.8 to 5.3 μm. When the particle size of the small particle titanium powder 122 is within this range, the pore structure size and its distribution inside the titanium powder mixture layer are more suitable, the synergistic transport effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, and the internal temperature of the electrolytic cell is easier to control.

[0029] In some embodiments, the average particle size of the large particle titanium powder 121 - the average particle size of the small particle titanium powder 122 is ≥ 15 μm, for example, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 46 μm, or an interval range formed by any two of the above values, so that the pore structure size and its distribution inside the titanium fiber felt substrate 11 are more suitable, the synergistic transport effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, and the internal temperature of the electrolytic cell is easier to control. In a preferred embodiment, the average particle size of the large particle titanium powder 121 - the average particle size of the small particle titanium powder 122 is within the range of 20 μm ≤ a - b ≤ 25 μm, to further improve the transport effect of water and oxygen and reduce the mass transfer loss.

[0030] In some embodiments, the average particle size of the large particle titanium powder 121 is 15 to 50 μm, such as 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or an interval range formed by any two of the above values.

[0031] In some embodiments, the average particle size of the small particle titanium powder 122 is ≤ 5.5 μm, such as 5 μm, 4 μm, 3.5 μm, or a range formed by any two of the above values.

[0032] In some embodiments, the thickness of the titanium powder mixture layer 12 is 15-80 μm, such as 15 μm, 20 μm, 25 μm, 30 μm, 25 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, or a range formed by any two of the above values. In one embodiment, the thickness of the titanium powder mixture layer 12 is 25-40 μm. When the thickness of the titanium powder mixture layer is in the range of 15-80 μm, especially in the range of 25-40 μm, both the improvement of the mass transfer effect and the performance loss caused by the long mass transfer path can be controlled.

[0033] In some embodiments, the thickness of the titanium fiber felt substrate 12 is 200-600 μm, such as 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, or a range formed by any two of the above values. In one embodiment, the thickness of the titanium fiber felt substrate 12 is 220-400 μm. When the thickness of the titanium fiber felt substrate 12 is in the range of 200-600 μm, especially in the range of 220-400 μm, both the improvement of the application range and the saving of materials can be achieved, and the use effect can also be taken into account.

[0034] In some embodiments, the titanium powder mixture layer 12 further comprises a conductive polymer and a binder.

[0035] In one embodiment, the weight of the conductive polymer is 0%-10% based on the total weight of the large particle titanium powder 121 and the small particle titanium powder 122. Illustratively, the conductive polymer includes at least one of polyaniline, polypyrrole, polythiophene, and derivatives thereof, but is not limited thereto.

[0036] In one embodiment, the weight of the binder is 6%-12% based on the total weight of the large particle titanium powder 121 and the small particle titanium powder 122. Illustratively, the binder is polytetrafluoroethylene.

[0037] In some embodiments, the method for preparing the titanium fiber felt composite material comprises the following steps:

[0038] Mixing the large particle titanium powder, the small particle titanium powder, the conductive polymer dispersion, and the binder dispersion, and dispersing to obtain a titanium powder mixture dispersion;

[0039] Spraying or brushing the titanium powder mixture dispersion liquid on the second surface of the titanium fiber felt substrate, and drying to obtain a titanium fiber felt composite material;

[0040] The mass ratio of the large particle titanium powder to the small particle titanium powder is 3:7-1:1; the particle size of the large particle titanium powder is 15-50 μm; and the particle size of the small particle titanium powder is less than 5.5 μm.

[0041] The porosity of the titanium fiber felt substrate is 50%-70%, and the average pore size is 30-60 μm.

[0042] For example, the mass ratio of the large particle titanium powder to the small particle titanium powder is 3:7, 3.5:6.5, 4:6, 4.5:5.5, 1:1, or a range formed by any two of the above values; the particle size of the large particle titanium powder is 15-45 μm, 15-40 μm, 16-35 μm, or 20-30 μm; the particle size of the small particle titanium powder is 5-4.1 μm or 4.8-4.5 μm; the porosity of the titanium fiber felt substrate is 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, or a range formed by any two of the above values; and the average pore size of the titanium fiber felt substrate is 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, or a range formed by any two of the above values.

[0043] In one embodiment, the average particle size of the large particle titanium powder is greater than or equal to the average particle size of the small particle titanium powder, and the average particle size of the large particle titanium powder is, for example, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 46 μm, or a range formed by any two of the above values.

[0044] In one embodiment, the average particle size of the large particle titanium powder is 20-25 μm, for example, 20 μm, 2 μm, 25 μm, or a range formed by any two of the above values.

[0045] In one embodiment, the average particle size of the small particle titanium powder is 3.8-5.3 μm, for example, 5 μm, 4 μm, or a range formed by any two of the above values.

[0046] In one embodiment, the sum of the mass fractions of the large particle titanium powder and the small particle titanium powder in the titanium powder mixture dispersion liquid is 80%-95%.

[0047] In one embodiment, the weight of the conductive polymer in the titanium powder mixture dispersion liquid is 0%-10% based on the total weight of the large particle titanium powder and the small particle titanium powder, and the weight of the binder is 6%-12%.

[0048] In one embodiment, the conductive polymer includes at least one of polyaniline, polypyrrole, polythiophene, and derivatives thereof, but is not limited thereto.

[0049] In one embodiment, the binder is polytetrafluoroethylene.

[0050] The conductive polymer dispersion liquid can be obtained by dispersing a conductive polymer in a solvent, or can be purchased directly. The mass fraction of the conductive polymer in the conductive polymer dispersion liquid can be selected to be 10% to 20%.

[0051] The binder dispersion liquid can be obtained by dispersing a binder in a solvent, or can be purchased directly. The mass fraction of the conductive polymer in the conductive polymer dispersion liquid can be selected to be 10% to 20%.

[0052] In one embodiment, the thickness of the titanium fiber felt substrate is 200 to 600 μm.

[0053] In one embodiment, the thickness of the titanium powder mixture layer formed is 15 to 80 μm.

[0054] In one embodiment, the titanium fiber felt substrate is cleaned and dried before spraying.

[0055] According to a third aspect of the present application, a PEM electrolytic cell is also provided, which includes an anode gas diffusion layer, the anode gas diffusion layer including the titanium fiber felt composite material described above.

[0056] In some embodiments, the PEM electrolytic cell further includes an anode bipolar plate and a proton exchange membrane, the anode side of the proton exchange membrane being provided with a catalyst coating layer;

[0057] The titanium powder mixture layer 12 of the titanium fiber felt composite material is adjacent to the anode bipolar plate or to the catalyst coating layer on the anode side of the proton exchange membrane.

[0058] The present application is further described below with specific examples, in which the conductive polymer dispersion liquid is a polyaniline dispersion liquid, the mass fraction of polyaniline in the polyaniline dispersion liquid is 12%, and the solvent is water;

[0059] The polytetrafluoroethylene dispersion liquid used has a mass fraction of 10% polytetrafluoroethylene, and is manufactured by DuPont.

[0060] Example 1

[0061] The present embodiment provides a titanium fiber felt composite material, which includes:

[0062] a titanium fiber felt substrate layer having a first surface and a second surface arranged oppositely;

[0063] a titanium powder mixture layer on the second surface of the titanium fiber felt substrate layer;

[0064] wherein the titanium powder mixture comprises large particle titanium powder, small particle titanium powder, electrically conductive polymer, and binder. The method for producing the titanium fiber felt composite of this embodiment comprises the following steps:

[0065] mixing and dispersing the large particle titanium powder, the small particle titanium powder, the electrically conductive polymer dispersion, and the binder dispersion to obtain a titanium powder mixture dispersion, wherein the particle diameter and average particle diameter of the large particle titanium powder, the particle diameter and average particle diameter of the small particle titanium powder, the mass ratio of the small particle titanium powder to the large particle titanium powder, the ratio of the weight of the electrically conductive polymer to the total weight of the large particle titanium powder and the small particle titanium powder, and the ratio of the weight of the binder to the total weight of the large particle titanium powder and the small particle titanium powder are as shown in Table 1;

[0066] applying the obtained titanium powder mixture dispersion to the second surface of the titanium fiber felt substrate by spraying, and drying to obtain a titanium fiber felt composite, wherein the porosity, average pore diameter, and thickness of the titanium fiber felt substrate used, and the thickness of the titanium powder mixture layer formed are as shown in Table 1.

[0067] Examples 2 to 17 and Comparative Examples 1 and 2

[0068] These examples and comparative examples each provide a titanium fiber felt composite, and the difference in the method for producing them from Example 1 is that:

[0069] the particle diameter and average particle diameter of the large particle titanium powder, the particle diameter and average particle diameter of the small particle titanium powder, the mass ratio of the small particle titanium powder to the large particle titanium powder, the ratio of the weight of the electrically conductive polymer to the total weight of the large particle titanium powder and the small particle titanium powder, and the ratio of the weight of the binder to the total weight of the large particle titanium powder and the small particle titanium powder are as shown in Table 1 or Table 2;

[0070] the amount of the titanium powder mixture dispersion sprayed is adjusted to adjust the thickness of the titanium powder mixture layer, and the thickness of the titanium powder mixture layer, and the porosity, average pore diameter, and thickness of the titanium fiber felt substrate used are as shown in Table 1 or Table 2.

[0071] Table 1

[0072]

[0073]

[0074] Table 2

[0075]

[0076]

[0077] Comparative Example 3

[0078] The comparative example provides a titanium fiber felt composite material, the difference between the preparation method and example 1 is that the titanium fiber felt substrate is directly used as the titanium fiber felt composite material.

[0079] The titanium fiber felt composite materials obtained in the above examples and comparative examples are respectively assembled into 25cm 2 The PEM electrolysis cell is subjected to electrolysis cell steady-state polarization curve test, the anode catalyst is 1mg / cm 2 Ir black, the cathode catalyst is 0.3mgPt / cm 2 40wt%Pt / C, the proton exchange membrane is GORE 80μm thickness film, wherein the first surface of the titanium fiber felt composite material in examples 1-17 and comparative examples 1-3 is adjacent to the anode bipolar plate. The test temperature is 80℃, and the test results are shown in table 5.

[0080] Table 5

[0081]

[0082]

[0083] As can be seen from the above, using the titanium fiber felt composite material of each example as the anode gas diffusion layer, excellent water-gas co-transport effect can be obtained, the mass transfer loss is low, and the current density is above 1.90A / cm 2 @2.0V.

[0084] In comparative examples 1-2, the titanium powder in the titanium powder mixture layer is only large particles or small particles, which makes the pore size in the titanium fiber felt composite material overall small or large, which is not conducive to water-gas co-transport, the mass transfer loss is high, and the current density is low. In comparative example 3, the titanium fiber felt substrate is directly used as the anode gas diffusion layer, the water-gas co-transport effect is relatively poor, the mass transfer loss is high, and the current density is low.

[0085] As can be seen from the comparison of examples 1, 7-10, when the thickness of the titanium powder mixture layer is controlled in the range of 25-40μm, the water-gas transport effect is better, the mass transfer loss is lower, and the current density is higher.

[0086] As can be seen from the comparison of examples 1, 13-15, when the thickness of the titanium fiber felt substrate is in the range of 220-400μm, not only the mass transfer loss is low and the current density is high, but also the mechanical properties are good, and the comprehensive performance is better.

[0087] Finally, it should be noted that the above examples are only used to illustrate the technical solutions herein and do not limit the scope of protection. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions herein can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions herein.

Claims

1. A titanium fiber felt composite material, characterized in that: include: The titanium fiber felt substrate layer has a first surface and a second surface opposite to each other; a titanium powder mixture layer, located on the second surface of the titanium fiber felt substrate layer; The titanium powder mixture layer comprises large-particle titanium powder and small-particle titanium powder, the mass ratio of the small-particle titanium powder to the large-particle titanium powder is 3:7 to 1:1, the particle size of the large-particle titanium powder is in the range of 15 to 50 μm, and the particle size of the small-particle titanium powder is less than 5.5 μm; The porosity of the titanium fiber felt substrate layer is 50% to 70%, and the average pore diameter is 30 to 60 μm.

2. The titanium fiber felt composite material according to claim 1, characterized in that The particle size of the large-particle titanium powder is in the range of 21.2 to 30 μm.

3. The titanium fiber felt composite material according to claim 1, wherein The particle size of the small-particle titanium powder is in the range of 3.8 to 5.3 μm.

4. The titanium fiber felt composite material according to claim 1, wherein The average particle size of the large-particle titanium powder minus the average particle size of the small particles is ≥15 μm; preferably 20 μm≤ab≤25 μm.

5. The titanium fiber felt composite material according to claim 1, wherein The thickness of the titanium powder mixture layer is 15 to 80 μm, preferably 25 to 40 μm.

6. The titanium fiber felt composite material according to claim 1, characterized in that The thickness of the titanium fiber felt substrate layer is 200 to 600 μm, preferably 220 to 400 μm.

7. The titanium fiber felt composite material according to claim 1, wherein The titanium powder mixture layer further comprises a conductive polymer and a binder.

8. The titanium fiber felt composite material according to claim 7, characterized in that: At least one of the following conditions is met: S1. The weight of the conductive polymer is 0 to 10% based on the total weight of the large titanium powder and the small titanium powder; S2. The weight of the binder is 6% to 12% based on the total weight of the large titanium powder and the small titanium powder; S3. The conductive polymer comprises at least one of polyaniline, polypyrrole, polythiophene and derivatives thereof; S4. The adhesive is polytetrafluoroethylene.

9. A PEM electrolytic cell, characterized in that: The anode gas diffusion layer comprises an anode gas diffusion layer, wherein the anode gas diffusion layer comprises the titanium fiber felt composite material according to any one of claims 1 to 8.

10. The PEM electrolytic cell according to claim 9, wherein The PEM electrolytic cell also includes an anode bipolar plate and a proton exchange membrane, the anode side of the proton exchange membrane is provided with a catalyst coating; the titanium powder mixture layer of the titanium fiber felt composite material is adjacent to the anode bipolar plate or the catalyst coating on the anode side of the proton exchange membrane.

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