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 is filled in the titanium fibrofelt base material on one side of the second surface of the titanium fibrofelt base material, and the particle size of the first titanium powder, the particle size of the second titanium powder, the mass ratio of the first titanium powder to the second titanium powder, and the porosity and the average pore size of the titanium fibrofelt base material are controlled to be within a proper range; the titanium fibrofelt composite material has the advantages that the titanium fibrofelt base material can be well filled with the titanium powder, and a pore structure with proper pore diameter and pore diameter distribution can be formed in the titanium fibrofelt base material, so that when the titanium fibrofelt 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 service life of the electrolytic tank is prolonged. 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] When the PEM electrolytic cell is running, at the anode, the reactant water reaches the catalytic layer reaction zone from the bipolar plate flow channel through the gas diffusion layer, and the product oxygen reaches the bipolar plate flow channel from the catalytic layer reaction zone through the gas diffusion layer. In the actual operation process of the electrolytic cell, the reactant water and the product oxygen are often blocked in the gas diffusion layer due to the opposite transmission directions of the reactant water and the product oxygen, the transmission of the water and the oxygen is blocked, the reactant water cannot reach the reaction zone in time, and thus the mass transfer loss of the electrolytic cell is increased. In the running process of the electrolytic cell, heat is generated in the proton exchange membrane and the catalytic layer, which may cause the temperature of the proton exchange membrane and the catalytic layer to rise. The product oxygen is discharged and carries away part of the heat, and the water that has not reacted and is transmitted out of the catalytic layer also carries away part of the heat. Therefore, if the transmission of the water and the oxygen is blocked, it will also have an adverse effect on the heat dissipation in the catalytic layer. Therefore, improving the cooperative transmission capacity of the water and the oxygen in the gas diffusion layer will be beneficial to the smooth transmission of the water and the oxygen, thereby reducing the mass transfer loss and being more conducive to controlling the internal temperature of the electrolytic cell.

[0003] At present, the anode gas diffusion layer mainly has two structures. One is a titanium fiber felt without a "microporous layer". The main disadvantage of this structure is that the internal pore size is large, and the cooperative transmission effect of the water and the oxygen is poor. The other is a double-layer structure composed of a "microporous layer" and a titanium fiber felt base layer. In the double-layer structure, the internal pore size of the "microporous layer" is small and the pore size distribution is concentrated, and the internal pore size of the titanium fiber felt base layer is large. The transmission of the water and the oxygen in the gas diffusion layer of the double-layer structure is poor, and the cooperative transmission effect of the water and the oxygen is poor. SUMMARY

[0004] The present application aims to overcome the shortcomings 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, the cooperative transmission effect of the water and the oxygen is good, the mass transfer loss of the electrolytic cell in the running process is low, and the internal temperature of the electrolytic cell is easy to control.

[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 base material having a first surface and a second surface arranged oppositely;

[0007] a titanium powder mixture filled in the titanium fiber felt base material on the side of the second surface;

[0008] The titanium fiber felt substrate has a porosity of 50% to 70% and an average pore size of 50 to 80 microns.

[0009] The titanium fiber felt substrate has a porosity of 50% to 70% and an average pore size of 50 to 80 microns.

[0010] In a second aspect, the 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 following beneficial effects: the titanium fiber felt composite material is prepared by filling the titanium powder mixture into the titanium fiber felt substrate on the second surface side of the titanium fiber felt substrate, and controlling the particle size of the first titanium powder, the particle size of the second titanium powder, the mass ratio of the first titanium powder to the second titanium powder, and the porosity and average pore size of the titanium fiber felt substrate within a suitable range, so that the titanium powder can be well filled in the titanium fiber felt substrate, and at the same time, a pore structure with a suitable pore size and pore size distribution can be formed in the titanium fiber felt substrate, and 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 of the electrolytic cell during operation is low, and the temperature in the electrolytic cell is easy to control. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The titanium fiber felt composite material is shown in the structural schematic view, wherein 1 is a titanium fiber felt substrate, 2 is a first surface, 3 is a second surface, 4 is a titanium powder mixture, 5 is a first titanium powder, and 6 is a second 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 of the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are some embodiments of the application, but not all the embodiments of the application. Based on the embodiments of 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 technical features described in an open form include a closed technical scheme composed of listed features, and also includes an open technical scheme containing the listed features.

[0015] In the present application, the numerical range is involved, such as the above numerical range is considered to be continuous, and includes the minimum value and the maximum value of the range, and every value between the minimum value and the maximum value. Further, when the range refers to an integer, every integer between the minimum value and the maximum value of the range is included. In addition, when a plurality of ranges are provided to describe a feature or a characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

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

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

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

[0019] A titanium fiber felt substrate 1 having a first surface 2 and a second surface 3 arranged opposite to each other;

[0020] A titanium powder mixture 4 filled in the inside of the titanium fiber felt substrate on the side of the second surface 3;

[0021] The titanium powder mixture 4 comprises a first titanium powder 5 and a second titanium powder 6, and the mass ratio of the second titanium powder 6 to the first titanium powder 5 is 1:1 to 2:1, the particle size of the first titanium powder 5 is in the range of 15 to 50 μm, and the particle size of the second titanium powder 6 is below 5.5 μm.

[0022] The porosity of the titanium fiber felt substrate 1 is 50% to 70%, and the average pore size is 50 to 80 μm.

[0023] The first titanium powder 5 and the second titanium powder 6 are each independently at least one of a primary particle or a primary particle agglomerate.

[0024] By filling the titanium powder mixture 4 in the inside of the titanium fiber felt substrate on the side of the second surface 3 with a specific porosity and average pore size, a pore size structure with small pore size (<5 μm), medium pore size (5 to 20 μm), and large pore size (>20 μm) and appropriate pore size distribution is formed by using the first titanium powder 5 and the second titanium powder 6 in the same fluid transport layer, wherein the small pore size can promote the transport of water by capillary action; the medium pore size can transport both water and oxygen; the large pore size can alleviate the water blockage of the pores, facilitate the smooth transport of oxygen, and help the titanium fiber felt composite material 1 to serve as the anode gas diffusion layer of the PEM electrolytic cell, thereby facilitating the simultaneous transport of water and oxygen, reducing the mass transfer loss during the operation of the electrolytic cell, improving the current density, and making it easy to control the internal temperature of the electrolytic cell.

[0025] The particle size of the first titanium powder 5, the particle size of the second titanium powder 6, the mass ratio of the first titanium powder 5 to the second titanium powder 6, and the porosity and average pore size of the titanium fiber felt substrate 1 are all closely related to the filling of the titanium powder mixture 4 inside the titanium fiber felt substrate 1 and the pore size and pore size distribution of the pore structure formed inside the titanium fiber felt substrate 1. The present application needs to control these parameters to be within the appropriate range, so that the titanium powder can be well filled inside the titanium fiber felt substrate 1, while the pore structure with appropriate pore size and pore size distribution can be formed inside the titanium fiber felt substrate 1, so that when the titanium fiber felt composite is used as the anode gas diffusion layer of the PEM electrolytic cell, the water and oxygen have good synergistic transmission effect, the mass transfer loss during the operation of the electrolytic cell is low, the current density is high, and the internal temperature of the electrolytic cell is easy to control.

[0026] The mass ratio of the first titanium powder 5 and the second titanium powder 6 needs to be controlled within the range of 1:1 to 2:1, such as 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1 or the interval range formed by any two of the above values; the particle size of the first titanium powder 5 needs to be within the range of 15-50 μm, such as 15-48 μm, 18-48 μm, 20-45 μm, 23-40 μm, 26-35 μm, 28-30 μm, 15-45 μm, 15-40 μm, 16-35 μm or 20-30 μm, etc.; the second titanium powder 6 needs to be below 5.5 μm, such as 5-4 μm, 4.8-4.5 μm or 4.5-4.2 μm, etc.; the porosity of the titanium fiber felt substrate 1 needs to be controlled within the range of 50%-70%, such as 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70% or the interval range formed by any two of the above values; the average pore size of the titanium fiber felt substrate 1 needs to be controlled within the range of 50-80 μm, such as 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm or the interval range formed by any two of the above values.

[0027] In some embodiments, the particle size of the first titanium powder 5 is within the range of 21.2-30 μm. When the particle size of the first titanium powder 5 is within this range, the pore structure size and its distribution inside the titanium fiber felt substrate 1 are more appropriate, and the synergistic transmission effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, the current density is high, and the internal temperature of the electrolytic cell is easier to control.

[0028] In some embodiments, the particle size of the second titanium powder 6 is within the range of 3.8-5.3 μm. When the particle size of the second titanium powder 6 is within this range, the pore structure size and its distribution inside the titanium fiber felt substrate 1 are more appropriate, and the synergistic transmission effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, the current density is high, and the internal temperature of the electrolytic cell is easier to control.

[0029] In some embodiments, the average particle size of the first titanium powder 5 is greater than or equal to 10 pm, for example, 10 pm, 15 pm, 20 pm, 25 pm, 30 pm, 35 pm, 40 pm, 45 pm, 48 pm, or a range formed by any two of the above values, so that the pore structure size and its distribution inside the titanium fiber felt substrate 1 are more suitable, and the synergistic transport effect of water and oxygen is better, the mass transfer loss during the operation of the electrolytic cell is lower, the current density is higher, and the temperature inside the electrolytic cell is easier to control.

[0030] In some embodiments, the average particle size of the first titanium powder 5 is 15-50 pm, such as 15 pm, 20 pm, 25 pm, 30 pm, 35 pm, 40 pm, 45 pm, 50 pm, or a range formed by any two of the above values.

[0031] In some embodiments, the average particle size of the second titanium powder 6 is 3.8-5.3 pm, such as 5 pm, 4.5 pm, 4 pm, or a range formed by any two of the above values.

[0032] The particle size of the first titanium powder 5 and the particle size of the second titanium powder 6 are obtained by sieving method, and the average particle size of the first titanium powder 5 and the average particle size of the second titanium powder 6 are measured by laser particle size method; the porosity of the titanium fiber felt substrate is obtained by, and the average pore size is obtained by.

[0033] In some embodiments, the total filling amount of the first titanium powder 5 and the second titanium powder 6 in the titanium fiber felt substrate 11 is 0.05-0.3 g / cm 2 , such as 0.05 g / cm 2 , 0.1 g / cm 2 , 0.15 g / cm 2 , 0.2 g / cm 2 , 0.25 g / cm 2 , 0.3 g / cm 2 , or a range formed by any two of the above values. In one embodiment, the total filling amount of the first titanium powder 5 and the second titanium powder 6 in the titanium fiber felt substrate 1 is 0.1-0.15 g / cm 2 .

[0034] When the total filling amount of the first titanium powder 5 and the second titanium powder 6 in the titanium fiber felt substrate 1 is in the range of 0.05-0.3 g / cm 2 , especially in the range of 0.1-0.15 g / cm 2 , it helps to form a more suitable pore structure inside the titanium fiber felt substrate 1 while achieving effective filling of the titanium powder mixture 4 inside the titanium fiber felt substrate 1, so that 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 temperature inside the electrolytic cell is easier to control.

[0035] In some embodiments, the filling thickness of the titanium powder mixture 4 is 5% to 40%, such as 5%, 7%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, or a range formed by any two of the above values, of the thickness of the titanium fiber felt substrate 1.

[0036] When the filling thickness of the titanium powder mixture 4 is 5% to 40%, especially 10% to 20%, of the thickness of the titanium fiber felt substrate 1, the pore structure inside the titanium fiber felt substrate 1 is more suitable, and 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 temperature inside the electrolytic cell is easier to control.

[0037] The filling thickness of the titanium powder mixture 4 is obtained by the following method: cutting the titanium fiber felt composite material, randomly measuring the filling thickness of the titanium powder mixture 4 at 5 places, and taking the average value.

[0038] In some embodiments, the thickness of the titanium fiber felt substrate 1 is 200 to 800 μm, such as 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, or a range formed by any two of the above values. In one embodiment, the thickness of the titanium fiber felt substrate 1 is 250 to 400 μm. When the thickness of the titanium fiber felt substrate 1 is in the range of 200 to 800 μm, especially in the range of 250 to 400 μm, the use effect of the gas diffusion layer prepared from the titanium fiber felt composite material is more suitable, and the mechanical properties are better.

[0039] In some embodiments, the titanium powder mixture 4 further comprises a conductive polymer and a binder.

[0040] In one embodiment, the weight of the conductive polymer is 0% to 10% based on the total weight of the first titanium powder 5 and the second titanium powder 6. Illustratively, the conductive polymer includes at least one of polyaniline, polypyrrole, polythiophene, and derivatives thereof, but is not limited thereto.

[0041] In one embodiment, the weight of the binder is 5% to 10% based on the total weight of the first titanium powder 5 and the second titanium powder 6. Illustratively, the binder is polytetrafluoroethylene.

[0042] In some embodiments, the method for preparing the titanium fiber felt composite material comprises the following steps:

[0043] mixing the first titanium powder, the second titanium powder, the conductive polymer dispersion, and the binder dispersion, and dispersing to obtain a titanium powder mixture dispersion;

[0044] The titanium fiber felt composite material is obtained by spraying the titanium powder mixture dispersion liquid to the second surface of the titanium fiber felt substrate by using a pressurized air gun, simultaneously vacuumizing at the first surface of the titanium fiber felt substrate, and drying after the spraying is completed.

[0045] In one embodiment, the mass ratio of the large particle titanium powder to the small particle titanium powder is 1:1 to 2:1, such as 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, or a range formed by any two of the above values.

[0046] In one embodiment, the particle size of the first titanium powder is 15 to 50 μm, such as 18 to 48 μm, 20 to 45 μm, 23 to 40 μm, 26 to 35 μm, 28 to 30 μm, 15 to 45 μm, 15 to 40 μm, 16 to 35 μm, or 20 to 30 μm, etc.

[0047] In one embodiment, the particle size of the second titanium powder is below 5.5 μm, such as 5 to 4 μm, 4.8 to 4.5 μm, or 4.5 to 4.2 μm, etc.

[0048] In one embodiment, the average particle size of the first titanium powder is greater than the average particle size of the second titanium powder by 10 μm or more, such as 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 48 μm, or a range formed by any two of the above values.

[0049] In one embodiment, the average particle size of the first titanium powder is 15 to 50 μm, such as 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or a range formed by any two of the above values.

[0050] In one embodiment, the average particle size of the second titanium powder is 3.8 to 5.3 μm, such as 5 μm, 4 μm, or a range formed by any two of the above values.

[0051] In one embodiment, the sum of the mass fractions of the first titanium powder and the second titanium powder in the titanium powder mixture dispersion liquid is 80% to 95%.

[0052] In one embodiment, the weight of the conductive polymer is 0% to 7% and the weight of the binder is 5% to 10%, based on the total weight of the first titanium powder and the second titanium powder.

[0053] In one embodiment, the conductive polymer includes at least one of polyaniline, polypyrrole, polythiophene, and derivatives thereof, but is not limited thereto.

[0054] In one embodiment, the binder is polytetrafluoroethylene.

[0055] The conductive polymer dispersion can be commercially available. The mass fraction of the conductive polymer in the conductive polymer dispersion can be selected to be 10% to 20%.

[0056] The binder dispersion can be commercially available. The mass fraction of the conductive polymer in the binder dispersion can be selected to be 10% to 20%.

[0057] In one embodiment, the titanium fiber felt substrate has a porosity of 50% to 70% and an average pore size of 50 to 80 μm.

[0058] In one embodiment, the titanium fiber felt substrate has a thickness of 200 to 800 μm.

[0059] In one embodiment, the pressure during pressure air gun spraying is 0.5 to 2 barg.

[0060] In one embodiment, the vacuum degree during vacuum extraction at the first surface of the titanium fiber felt substrate is 0.1 to 0.5 barg.

[0061] In one embodiment, the total spraying mass of the first titanium powder and the second titanium powder per square centimeter of the titanium fiber felt substrate is 0.05 to 0.3 g during spraying of the titanium powder mixture dispersion.

[0062] In one embodiment, 0.01 to 0.03 mL of the titanium powder mixture dispersion is sprayed per square centimeter of the titanium fiber felt substrate during spraying of the titanium powder mixture dispersion, the spraying is paused, and the spraying is restarted after drying, and the process is repeated.

[0063] In one embodiment, the titanium fiber felt substrate is cleaned and dried before spraying.

[0064] According to a second aspect of the present application, a PEM electrolytic cell is also provided, which comprises an anode gas diffusion layer, the anode gas diffusion layer comprising the titanium fiber felt composite described above.

[0065] In some embodiments, the PEM electrolytic cell further comprises an anode bipolar plate and a proton exchange membrane, the anode side of the proton exchange membrane being provided with a catalyst coating.

[0066] In some embodiments, the PEM electrolytic cell further comprises an anode bipolar plate, the first surface 2 or the second surface 3 of the titanium fiber felt substrate 1 being adjacent to the anode bipolar plate. When the first surface 2 of the titanium fiber felt substrate 1 is adjacent to the anode bipolar plate, the synergistic transport of water and oxygen is better, so that the mass transfer loss during operation of the electrolytic cell is lower, and the temperature inside the electrolytic cell is easier to control.

[0067] The conductive polymer dispersion is a polyaniline dispersion, the mass fraction of polyaniline in the polyaniline dispersion is 12%, and the solvent is water.

[0068] The binder dispersion is a polytetrafluoroethylene dispersion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene dispersion is 10%, and the manufacturer is DuPont.

[0069] Example 1

[0070] The titanium fiber felt composite material provided by the example comprises:

[0071] The titanium fiber felt substrate has oppositely arranged first and second surfaces;

[0072] The titanium powder mixture is filled in the titanium fiber felt substrate on the side of the second surface;

[0073] The titanium powder mixture comprises first titanium powder, second titanium powder, conductive polymer, and binder. The preparation method of the titanium fiber felt composite material of the example comprises the following steps:

[0074] The first titanium powder, the second titanium powder, the conductive polymer dispersion, and the binder dispersion are mixed and dispersed to obtain a titanium powder mixture dispersion. The particle size and average particle size of the first titanium powder, the particle size and average particle size of the second titanium powder, the mass ratio of the second titanium powder to the first titanium powder, the type of conductive polymer in the conductive polymer dispersion, the ratio of the weight of the conductive polymer to the total weight of the first titanium powder and the second titanium powder, the type of binder in the binder dispersion, and the ratio of the weight of the binder to the total weight of the first titanium powder and the second titanium powder are shown in Table 1.

[0075] The obtained titanium powder mixture dispersion is sprayed onto the second surface of the titanium fiber felt substrate by using a pressurized air gun spraying method, and vacuum is drawn at the first surface of the titanium fiber felt substrate. When spraying the titanium powder mixture dispersion, 0.02 mL of the titanium powder mixture dispersion is sprayed per square centimeter of the titanium fiber felt substrate, and then the spraying is paused after drying. The spraying is restarted, and the process is repeated to obtain the titanium fiber felt composite material. The pressure of the pressurized air gun is 0.5 barg, the vacuum degree is 0.2 barg when vacuum is drawn at the first surface of the titanium fiber felt substrate, the porosity, average pore size, and thickness of the titanium fiber felt substrate, the total filling amount of the first titanium powder and the second titanium powder in the titanium fiber felt substrate, and the ratio of the filling thickness of the titanium powder mixture to the thickness of the titanium fiber felt substrate are shown in Table 1.

[0076] Examples 2-16 and Comparative Examples 1-2

[0077] The examples and comparative examples all provide a titanium fiber felt composite material, and the difference between their preparation methods and Example 1 is that:

[0078] The particle size and average particle size of the first titanium powder, the particle size and average particle size of the second titanium powder, the mass ratio of the second titanium powder to the first titanium powder, the ratio of the weight of the conductive polymer to the total weight of the first titanium powder and the second titanium powder, and the ratio of the weight of the binder to the total weight of the first titanium powder and the second titanium powder are shown in Table 1 or Table 2;

[0079] The total amount of spraying of the titanium powder mixture dispersion is adjusted to adjust the total filling amount of the first titanium powder and the second titanium powder in the titanium fiber felt substrate; and / or the pressure of the pressurized air gun and the vacuum degree when vacuumizing at the first surface of the titanium fiber felt substrate are adjusted to adjust the ratio of the filling thickness of the titanium powder mixture to the thickness of the titanium fiber felt substrate, the total filling amount of the first titanium powder and the second titanium powder in the titanium fiber felt substrate, the ratio of the filling thickness of the titanium powder mixture to the thickness of the titanium fiber felt substrate, and the porosity, average pore size and thickness of the titanium fiber felt substrate used are shown in Table 1 or Table 2.

[0080] Comparative Example 3

[0081] This comparative example provides a titanium fiber felt composite material, the difference between its preparation method and Example 1 is that the titanium fiber felt substrate is directly used as the titanium fiber felt composite material.

[0082] Table 1

[0083]

[0084]

[0085] Table 2

[0086]

[0087] Effect Example

[0088] The titanium fiber felt composite materials obtained in the above examples and comparative examples are assembled into 25cm 2 PEM electrolysis cell for electrolysis cell steady-state polarization curve test, the anode catalyst is 1mg / cm 2 Ir black, the cathode catalyst is 0.3mg Pt / cm 240wt% Pt / C, the proton exchange membrane is a Gore 80μm thick membrane, wherein effect examples 1 to 16 and comparative effect examples 1 to 3 respectively apply the titanium fiber felt composite materials of embodiments 1 to 16 and comparative examples 1 to 3, that is, the titanium fiber felt composite material of embodiment 1 is applied in effect example 1, the titanium fiber felt composite material of embodiment 2 is applied in effect example 2... the titanium fiber felt composite material of embodiment 16 is applied in effect example 16, the titanium fiber felt composite material of comparative example 1 is applied in comparative effect example 1, the titanium fiber felt composite material of comparative example 2 is applied in comparative effect example 2, and the titanium fiber felt composite material of comparative example 3 is applied in comparative effect example 3, and the first surfaces of the titanium fiber felt composite materials of embodiments 1 to 16 and comparative examples 1 to 3 are adjacent to the anode bipolar plate.

[0089] Table 5

[0090] Current density A / cm 2 @2.0 V Example 1 1.99 Example 2 2.01 Example 3 1.97 Example 4 2.13 Example 5 1.89 Example 6 2.05 Example 7 1.90 Example 8 1.93 Example 9 2.02 Example 10 1.88 Example 11 1.92 Example 12 2.02 Example 13 2.08 Example 14 2.03 Example 15 2.04 Example 16 1.93 Comparative Example 1 1.86 Comparative Example 2 1.79 Comparative Example 3 1.76

[0091] According to the above data, the application of the titanium fiber felt composite materials of each embodiment as the anode gas diffusion layer can achieve excellent water-gas synergistic transmission effect, low mass transfer loss, and a current density of 1.89A / cm 2 @2.0V or above.

[0092] Comparative Example 3 directly uses titanium fiber felt substrate 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; Comparative Examples 1 to 2 only use large-particle titanium powder or small-particle titanium powder to fill the titanium fiber felt substrate, so that the pore size inside the titanium fiber felt composite material is generally small or large, which is not conducive to water-gas co-transport, the mass transfer loss is high, and the current density is low.

[0093] Comparison of Examples 1, 6 to 8 shows that the total filling amount of the first titanium powder and the second titanium powder in the titanium fiber felt substrate is controlled to be 0.1 to 0.15 g / cm 2 Within this range, the water vapor transmission effect is better, the mass transfer loss is lower, and the current density is higher.

[0094] Comparison of Examples 1 and 9 to 11 shows that controlling the filling thickness of the titanium powder mixture to be 10% to 20% of the thickness of the titanium fiber felt substrate can significantly improve water vapor transmission, reduce mass transfer loss, and increase current density.

[0095] From the comparison of Examples 1 and 14 to 16, it can be seen that when the thickness of the titanium fiber felt substrate is in the range of 250 to 400 μm, not only is the mass transfer loss low and the current density high, but also the mechanical properties are good and the overall performance is better.

[0096] Finally, it should be noted that the above examples are only used to illustrate the technical solutions herein and not to limit the scope of protection herein, and although the present 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 equivalently replaced without departing from the essence and scope of the technical solutions herein.

Claims

1. A titanium fiber felt composite material, characterized in that: include: A titanium fiber felt substrate having a first surface and a second surface opposite to each other; A titanium powder mixture is filled in the interior of the titanium fiber felt substrate on one side of the second surface; The titanium powder mixture comprises a first titanium powder and a second titanium powder, the mass ratio of the second titanium powder to the first titanium powder is 1:1 to 2:1, the particle size of the first titanium powder is in the range of 15 to 50 μm, and the particle size of the second titanium powder is less than 5.5 μm; The porosity of the titanium fiber felt substrate is 50% to 70%, and the average pore diameter is 50 to 80 μm.

2. The titanium fiber felt composite material according to claim 1, characterized in that The particle size of the first 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 second 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 a of the first titanium powder and the average particle size b of the second titanium powder satisfy the following conditions: ab≥10 μm; preferably 15 μm≤ab≤25 μm.

5. The titanium fiber felt composite material according to claim 1, wherein The total filling amount of the first titanium powder and the second titanium powder in the titanium fiber felt substrate is 0.05 to 0.3 g / cm 2 , preferably 0.1 to 0.15 g / cm 2 .

6. The titanium fiber felt composite material according to claim 1, characterized in that The filling thickness of the titanium powder mixture is 5% to 40% of the thickness of the titanium fiber felt substrate, preferably 10% to 20%.

7. The titanium fiber felt composite material according to claim 1, wherein The thickness of the titanium fiber felt substrate is 200-800 μm, preferably 250-400 μm.

8. The titanium fiber felt composite material according to claim 1, wherein: At least one of the following conditions (1) to (4) is also met: (1) The titanium powder mixture further comprises a binder, wherein the weight of the binder is 5% to 10% based on the total weight of the first titanium powder and the second titanium powder; (2) The titanium powder mixture further comprises a binder, and the binder is polytetrafluoroethylene; (3) The titanium powder mixture further comprises a conductive polymer, wherein the weight of the conductive polymer is 0% to 7% based on the total weight of the first titanium powder and the second titanium powder; (4) The titanium powder mixture further comprises a conductive polymer, wherein the conductive polymer comprises at least one of polyaniline, polypyrrole, polythiophene and derivatives thereof.

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 further includes an anode bipolar plate, and the first surface or the second surface of the titanium fiber felt substrate is adjacent to the anode bipolar plate.

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