Method for evaluating the performance of a proton exchange membrane fuel cell ink

Abstract

The application discloses an evaluation method for ink performance of a proton exchange membrane fuel cell and relates to the technical field of proton exchange membrane fuel cell detection. The application mainly adopts an electrochemical workstation to test the performance of dispersed slurry, simulates stress conditions under specific working conditions, and effectively distinguishes electrochemical active area attenuation caused by ionomer agglomeration and platinum particle separation in the slurry in combination with electrochemical response differences. The test result has high precision, a short cycle, and can obviously reduce marginal cost of slurry development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of proton exchange membrane fuel cell detection, and particularly relates to a method for evaluating ink performance of a proton exchange membrane fuel cell. BACKGROUND

[0002] The proton exchange membrane fuel cell is a high-efficiency and clean energy conversion device, which directly converts the chemical energy of hydrogen into electrical energy. Its core feature is to use a proton exchange membrane (PEM) as an electrolyte, has the advantages of fast start, high efficiency, low temperature operation, etc., and is one of the key technologies in the field of hydrogen energy application. The catalyst layer is the place where hydrogen and oxygen undergo electrochemical reaction to generate current in the fuel cell, and is the core of the fuel cell. It is mainly composed of platinum-based catalyst, ionomer and pore region. The conductive carrier conducts electrons, the ionomer conducts protons, and the pores transport reaction gas, which are crucial to the performance of the fuel cell. The catalyst layer directly determines the efficiency, cost, service life and application scenarios of the fuel cell, and its optimization needs to consider catalytic activity, mass transfer efficiency, durability and economy, which is one of the core challenges for the fuel cell technology to go from the laboratory to large-scale commercialization.

[0003] The microstructure of the catalyst layer is mainly determined by the ink performance and the preparation process of the catalyst layer, and the ink with good performance is the premise for preparing excellent catalyst layer; in the ink performance detection, the performance, dispersibility and utilization rate of the platinum-based catalyst have always been the focus of ink development, and the dispersity of the catalyst in the ink directly affects its electrochemical performance and utilization rate. At present, transmission electron microscopy (TEM), X-ray diffraction (XRD) and other technologies are generally used to detect the dispersion of the catalyst in the ink, and then evaluate the reduction of active sites in the catalyst layer caused by catalyst agglomeration. This method has the advantages of accuracy and intuitiveness, but it needs to prepare the ink into a catalyst layer, so there may be an influence of the catalyst morphology caused by the spraying or direct coating process of the catalyst layer, in addition, this method must use professional instruments, and the cost is high in the actual development process.

[0004] Electrochemical performance detection is another important means for evaluating the performance of the proton exchange membrane fuel cell ink. The electrochemical area is calculated by CV test on the ink, and the catalyst dispersion condition is indirectly evaluated by platinum active sites. However, it is found in actual operation that due to the influence of the formula and dispersion equipment, the agglomeration of ionomer in the ink and the separation of platinum nanoparticles from the carbon carrier will all lead to less electrochemical active area (ECSA) in the final electrochemical performance test. The specific reasons cannot be distinguished from the results, and further observation of the ionomer distribution by transmission electron microscopy (TEM) and the like is still needed.

[0005] In the development of proton exchange membrane fuel cell ink, ionomer agglomeration is mainly caused by poor compatibility between ionomer and solvent, insufficient stirring or ultrasonic dispersion of slurry, resulting in that ionomer fails to uniformly coat the catalyst, or the mass ratio of ionomer to catalyst is too high; and the separation of platinum nanoparticles is mainly caused by excessive mechanical shear force (such as high-speed ball milling) during the preparation of the slurry, which damages the combination of the catalyst and the carrier. Although they will both lead to the reduction of catalyst active sites, the solutions are not the same, and accurate differentiation of the causes is crucial for subsequent targeted modification of the ink. SUMMARY

[0006] The purpose of the present application is to overcome the defects of the prior art and provide a method for evaluating the performance of proton exchange membrane fuel cell ink, which simulates the stress conditions under specific working conditions, combines the differences in electrochemical response, and effectively distinguishes the electrochemical active area (ECSA) decay caused by ionomer agglomeration and platinum (Pt) particle separation in the slurry, so as to subsequently optimize the ink.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] The present application provides a method for evaluating the performance of proton exchange membrane fuel cell ink, comprising the following steps:

[0009] S1, preparing a proton exchange membrane fuel cell ink according to the original formula;

[0010] S2, adding the ink to a glassy carbon electrode, drying, and then testing the initial electrochemical performance to obtain a CV curve;

[0011] S3, performing an accelerated aging test on the ink using a triangular wave potential cycle, and then testing the electrochemical performance CV curve again after the test is completed;

[0012] S4, calculating the half-peak width of the hydrogen desorption region of the CV curve before and after the accelerated aging;

[0013] S5, distinguishing the type of electrochemical active area decay of the ink according to the change value of the half-peak width.

[0014] In some embodiments of the present application, in step S1, the ink comprises a catalyst, an ionomer, water and an organic alcohol;

[0015] The catalyst is a platinum-carbon catalyst with a mass ratio of 50%, and the platinum-carbon catalyst is selected from Tanaka TEC10E50E, Youmei Pt0550 or Platinum Source AD50;

[0016] The ionomer is a perfluorosulfonic acid resin, and the perfluorosulfonic acid resin is selected from DuPont D0520, DuPont D2020, Solvay 72 or Solvay 79;

[0017] The organic alcohol is selected from at least one of isopropyl alcohol, ethanol, ethylene glycol, n-butyl alcohol and n-propyl alcohol.

[0018] Further, the mass ratio of water: organic alcohol: ionomer: catalyst is 9-50: 10-50: 8-12: 1, and the total solid content of the catalyst and ionomer in the ink is 1%-20%. Further, the mass ratio of water: organic alcohol: ionomer: catalyst is 9-14: 10-14: 8-12: 1.

[0019] In some embodiments of the present application, the ink dispersion in step S1 uses a high-pressure homogenizer, the homogenization pressure is 800-1200 Pa, the motor frequency is 10-40 Hz, the homogenization time is 5-20 min, and the circulating cooling water is used to control the temperature between 5-10℃.

[0020] In some embodiments of the present application, in step S2, the diameter of the glassy carbon electrode is 5 mm, and the ink sampling amount is 2-5 μL;

[0021] In the electrochemical performance test, the test is carried out in an electrolyte, and the electrolyte is a 1 mol / L H2SO4 solution, and nitrogen bubbling is used for 30-60 min before the test;

[0022] The potential interval of the test is 0.05V-1.2V relative to the reversible hydrogen electrode RHE,

[0023] The scanning rate of the test is 20 mV / s.

[0024] Further, the electrochemical performance test uses a three-electrode system, in which the reference electrode is a mercury-mercury electrode, and the counter electrode is a platinum sheet electrode.

[0025] In some embodiments of the present application, in step S3, the potential interval of the triangular wave potential cycle is 0.4V-1.4V relative to the reversible hydrogen electrode RHE,

[0026] The scanning rate of the triangular wave potential cycle is 100 mV / s;

[0027] In the accelerated aging, the ink is placed in an electrolyte, and the electrolyte is a 1 mol / L H2SO4 solution, and the cycle number of the triangular wave potential cycle is 1000 cycles.

[0028] Preferably, the half-peak width calculation in step S4 specifically includes:

[0029] Identifying the hydrogen desorption peak current I peak ;

[0030] Determining the baseline current I baseline ;

[0031] The half-peak current I half : I half = (I peak - I baseline ) / 2 + I baseline ;

[0032] The left potential E half and the right potential E left on the CV curve are determined according to I right ;

[0033] The half-peak width E half : E half = |E left - E right | is calculated.

[0034] As a preferred solution, in step S5, the half-peak width calculated after the accelerated aging test is compared with the design target, and the data analysis is combined to analyze the attenuation of the electrochemical active surface area (ECSA) caused by the agglomeration of ionomers and the detachment of platinum (Pt) particles in the slurry, and then the ink is subsequently optimized in a targeted manner.

[0035] If the half-peak width of the CV curve of the accelerated aging test significantly increases, it indicates that the attenuation is mainly caused by the agglomeration of ionomers;

[0036] If the half-peak width of the CV curve of the accelerated aging test decreases, it indicates that the attenuation is mainly caused by the detachment of platinum particles.

[0037] If the above conditions do not exist, it indicates that the performance detection of the ink slurry is passed; if the above conditions exist, the ink formula or dispersion process is updated according to the type of attenuation, and the slurry is prepared again, and after the preparation is completed, the detection is continued until the performance detection is passed.

[0038] Fuel cell slurry testing is a bridge connecting materials science and engineering applications. Through systematic testing of multiple scales and multiple physical fields, the development cycle can be significantly shortened, the production yield can be improved, and the industry can move towards low cost and high durability. Slurry is the core material of the catalyst layer (CL), and the ratio of its components (such as catalyst, ionomer, solvent) and dispersion uniformity directly affect the reaction activity of the electrode. During the dispersion of fuel cell slurry, ionomer agglomeration will lead to uneven resin dispersion, affecting the distribution of the three-phase interface of the catalyst, ionomer and gas, and thus affecting the catalyst activity and utilization, resulting in a decrease in the electrochemical area. In addition, excessive dispersion of the slurry will reduce the instability of the catalyst carrier, which will cause platinum nanoparticles to separate from the carbon carrier during operation, especially at high potentials, and will also cause a decrease in the electrochemical area. Although the results are similar, the causes are completely different. Existing slurry testing methods, including viscosity, rheological property, and thixotropy tests, mainly test the material properties of the slurry after dispersion, and cannot directly distinguish between ionomer agglomeration and platinum nanoparticle detachment. Further characterization by scanning electron microscopy + energy dispersive spectrometer (SEM-EDS) and laser particle size analyzer is needed to determine the distribution uniformity and particle size distribution of the ionomer. This method has high development time and cost, and expensive equipment.

[0039] The present application mainly uses an electrochemical workstation to test the performance of dispersed slurry, simulates the stress conditions under specific working conditions, and effectively distinguishes the electrochemical active area (ECSA) decay caused by ionomer agglomeration and platinum (Pt) particle detachment based on the differences in electrochemical response. The test results have high precision and short cycle, and can significantly reduce the marginal cost of slurry development. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The flowchart of the present application.

[0041] Figure 2 The CV curve atlas before and after the durability test of Example 1.

[0042] Figure 3 The CV curve atlas before and after the durability test of Example 2.

[0043] Figure 4 The CV curve atlas before and after the durability test of Example 3.

[0044] Figure 5 The CV curve atlas before and after the durability test of Example 4.

[0045] Figure 6 The half-peak width calculation diagram of the example. DETAILED DESCRIPTION

[0046] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0047] Example 1

[0048] Weigh 1 g of Tanaka TEC10E50E catalyst (50% Pt / C) into a beaker, add 14 g of deionized water, and stir with a glass rod until the catalyst is completely soaked; then use an electronic balance to weigh 14 g of n-propanol and 8 g of perfluorosulfonic acid resin DuPont D0520, pre-treat the mixture with ultrasound for 30 minutes, and then transfer it to a high-pressure homogenizer; during the operation of the high-pressure homogenizer, turn on the circulating cooling water to maintain the operating temperature of the equipment (5-10°C), set the high-pressure homogenization pressure to 800 Pa, the motor frequency to 25 Hz, and perform high-pressure homogenization of the slurry for 5 minutes.

[0049] The material was collected in a small beaker and then subjected to electrochemical performance testing. The electrolyte was a 1 mol / L H₂SO₄ solution, which was bubbled with high-purity nitrogen for 30 minutes before testing to remove oxygen from the electrolyte. A 2μL slurry was pipetted onto a glassy carbon cell (5mm diameter). After air drying, it was transferred to a disk electrode for testing. The reference electrode was a calomel electrode, and the counter electrode was a platinum sheet. The electrochemical performance was tested using a CV scan between 0.05V and 1.2V (vs. reversible hydrogen electrode (RHE)) at a scan rate of 20mV / s.

[0050] After the initial performance test, the triangular wave cycling parameters were reset to conduct an accelerated aging test at 0.4V-1.4V (relative to the reversible hydrogen electrode (RHE)) for 1000 cycles at a scan rate of 100mV / s. After the test results were obtained, the electrochemical performance CV test was performed again. After the slurry CV performance test was completed, the half-peak width was calculated on the spectrum to test the changes before and after accelerated aging.

[0051] The half-peak width of the CV curves before and after accelerated aging is calculated, the selected area is the hydrogen desorption peak, and the peak current I of the hydrogen desorption peak is identified. peak ; Determine the baseline current I baseline ; Then calculate the half-peak current I according to the formula half :I half = (I peak -I baseline ) / 2 + I baseline ;

[0052] Then, according to the half-peak current, the half-peak potential point is determined from the CV curve, that is, the potential value corresponding to the half-peak current (left potential E left and right potential Eright

[0053] The half-peak width E half : E half = |E left - E right |.

[0054] Example 2

[0055] Take 1g of Tanaka TEC10E50E catalyst (50% Pt / C) in a beaker, add 14g of deionized water, stir with a glass rod until the catalyst is completely soaked; then use an electronic balance to weigh 14g of n-propanol and 8g of Nafion resin DuPont D0520, mix the materials with ultrasonic pretreatment for 30 minutes, then transfer to a high-pressure homogenizer; open the circulating cooling water during the operation of the high-pressure homogenizer to maintain the equipment operating temperature (5-10°C), set the high-pressure homogenization pressure to 800Pa, the motor frequency to 25Hz, and perform slurry high-pressure homogenization treatment for 20min.

[0056] Collect the material in a small beaker, then test its electrochemical performance. The electrolyte is 1mol / L H2SO4 solution, which is bubbled with high-purity nitrogen for 30min before testing to remove oxygen in the electrolyte; use a pipette to take 2μL of slurry and drop it on a glass carbon battery (5mm in diameter), then naturally air dry and transfer to a disc electrode for testing. The reference electrode is a mercury-mercury electrode and the counter electrode is a platinum sheet electrode. The electrochemical performance CV test is performed at 0.05V-1.2V (vs. reversible hydrogen electrode RHE) with a scan rate of 20mV / s.

[0057] After the initial performance test, the triangular wave cycle parameters are reset, and the accelerated aging test is performed at 0.4V-1.4V (vs. reversible hydrogen electrode RHE) with a scan rate of 100mV / s. After the test, the electrochemical performance CV test is performed again, and the half-peak width is calculated on the graph after the CV performance test of the slurry to test the change before and after the accelerated aging.

[0058] Example 3

[0059] Take 1g of Tanaka TEC10E50E catalyst (50% Pt / C) in a beaker, add 14g of deionized water, stir with a glass rod until the catalyst is completely soaked; then use an electronic balance to weigh 14g of n-propanol and 8g of Nafion resin DuPont D0520, mix the materials with ultrasonic pretreatment for 30 minutes, then transfer to a high-pressure homogenizer; open the circulating cooling water during the operation of the high-pressure homogenizer to maintain the equipment operating temperature (5-10°C), set the high-pressure homogenization pressure to 1200Pa, the motor frequency to 25Hz, and perform slurry high-pressure homogenization treatment for 20min.​

[0060] The material is collected in a small beaker and then subjected to electrochemical performance testing. Among them, the electrolyte is 1 mol / L H2SO4 solution, and high-purity nitrogen is bubbled for 30 min before testing to remove oxygen in the electrolyte; 2 μL of slurry is removed by a pipette gun, dropped onto a glass carbon battery (diameter 5 mm), naturally dried, and then transferred to a disc electrode for testing, wherein the reference electrode is a mercury-mercury electrode, and the counter electrode is a platinum plate electrode. The electrochemical performance CV test is performed in the range of 0.05V-1.2V (relative to reversible hydrogen electrode RHE) at a scan rate of 20 mV / s.

[0061] After the initial performance test is completed, the triangular wave cycle parameters are reset, and the accelerated aging test is performed at 0.4V-1.4V (relative to reversible hydrogen electrode RHE) with 1000 cycles and a scan rate of 100 mV / s. After the test results, the electrochemical performance CV test is performed again, and the slurry CV performance test is completed. The half-peak width is calculated on the graph to test the change before and after the accelerated aging.

[0062] Example 4

[0063] 1 g of Tanaka TEC10E50E catalyst (50% Pt / C) is weighed in a beaker, 9 g of deionized water is added, and the catalyst is stirred with a glass rod until it is completely immersed; then 10 g of n-propanol and 12 g of perfluorosulfonic acid resin DuPont D0520 are weighed in sequence with an electronic balance, and the mixture is pretreated with ultrasonic for 30 minutes, and then transferred to a high-pressure homogenizer. The circulating cooling water is turned on to maintain the equipment working temperature (5-10℃) during the operation of the high-pressure homogenizer, the high-pressure homogenization pressure is set to 800 Pa, the motor frequency is 25 Hz, and the slurry is subjected to high-pressure homogenization treatment for 20 min.

[0064] The material is collected in a small beaker and then subjected to electrochemical performance testing. Among them, the electrolyte is 1 mol / L H2SO4 solution, and high-purity nitrogen is bubbled for 30 min before testing to remove oxygen in the electrolyte; 2 μL of slurry is removed by a pipette gun, dropped onto a glass carbon battery (diameter 5 mm), naturally dried, and then transferred to a disc electrode for testing, wherein the reference electrode is a mercury-mercury electrode, and the counter electrode is a platinum plate electrode. The electrochemical performance CV test is performed in the range of 0.05V-1.2V (relative to reversible hydrogen electrode RHE) at a scan rate of 20 mV / s.

[0065] After the initial performance test is completed, the triangular wave cycle parameters are reset, 0.4V-1.4V (relative to reversible hydrogen electrode RHE) is used for accelerated aging test, the test cycle number is 1000 cycles, and the scanning rate is 100mV / s. After the test result, the electrochemical performance CV test is carried out again, and after the slurry CV performance test is completed, the half-peak width is calculated on the graph, and the change before and after the accelerated aging is tested.

[0066] Test Example 1

[0067] The test process of the embodiment of the application is as follows: Figure 1 As shown in the flowchart, the catalyst particle breakage phenomenon caused by uneven distribution of ionomers, agglomeration and excessive homogenization is artificially manufactured by changing the homogenization time, pressure and ionomer content of the high-pressure homogenizer in the embodiment;

[0068] The half-peak width calculation statistical table of examples 1 to 4 before and after the accelerated aging test is shown in table 1.

[0069] Table 1: Half-peak width calculation statistical table of examples

[0070]

[0071] As shown in table 1, for example 1 and example 2, when the ink formula is the same, the increase of the homogenization time of the high-pressure homogenizer to a certain extent, the ionomer agglomerates in the ink are further dispersed and dissociated, and then the CV curve of the ink after the durability test changes obviously. Figure 2 and Figure 3 For example 1, because the homogenization time is short, the ionomer agglomeration in the ink is serious, which leads to the increase of the CV curve hydrogen desorption peak half-peak width and the significant reduction of the carbon double-layer capacitance after the durability test. This is because the ionomer agglomeration in the ink leads to the obstruction of proton conduction, the reduction of reaction site utilization rate, the significant decrease of double-layer capacitance, the blockage of ionomer to the pores and the reduction of effective interface; example 2 increases the homogenization time, the ionomer agglomeration in the ink is alleviated, the half-peak width is reduced after the durability test, and the double-layer capacitance does not change obviously. The attenuation of the electrochemical area in the accelerated aging process is mainly caused by the migration and agglomeration of platinum nanoparticles.

[0072] Example 3 increases the homogenization pressure, the ink is subjected to excessive shearing, the carbon carrier of the catalyst is broken, the specific surface area is reduced, the catalyst particles are insufficiently exposed, the noble metal particles (such as Pt) lose support after the carbon carrier is broken, and migration or agglomeration occurs. In addition, the excessive shearing force can make the noble metal particles more easily peel off from the surface of the carbon carrier, reducing the number of active sites; after the durability test, the CV curve half-peak width of example 3 is reduced. Figure 4), and the amplitude is greater than that of Example 2, indicating that Example 3 has more loss of platinum active sites; Example 4 simulates the agglomeration of ionomers in the ink by increasing the ionomer content, and Figure 5 The test results of Example 4 show that after the durability test, the CV curve half-peak width increases obviously, and the value is greater than that of Example 1, and the carbon double-layer capacitance decreases obviously. This example further proves that the electrochemical method can effectively distinguish whether the electrochemical active area (ECSA) decay in the ink is caused by ionomer agglomeration or platinum (Pt) particle detachment, providing a direction for the optimization of subsequent ink formula and preparation process, and reducing the development cost.

Claims

1. A method for evaluating the performance of an ink for a proton exchange membrane fuel cell, characterized by, The method comprises the following steps: S1, preparing a proton exchange membrane fuel cell ink according to an original formula; S2, adding the ink to a glassy carbon electrode, drying, and then performing initial electrochemical performance testing to obtain a CV curve; S3, performing an accelerated aging test on the ink by using a triangular wave potential cycle, and then testing the electrochemical performance CV curve again after the test is completed; S4, calculating the half-peak width of the hydrogen desorption region of the CV curve before and after the accelerated aging; S5, distinguishing the electrochemical active area decay type of the ink according to the half-peak width change value.

2. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 1, characterized by, In step S1, the ink comprises a catalyst, an ionomer, water, and an organic alcohol; The catalyst is a platinum-carbon catalyst with a mass ratio of 50%, and the platinum-carbon catalyst is selected from Tanaka TEC10E50E, Youmei Pt0550, or Platinum Source AD50; The ionomer is a perfluorosulfonic acid resin, and the perfluorosulfonic acid resin is selected from DuPont D0520, DuPont D2020, Solvay 72, or Solvay 79; The organic alcohol is selected from at least one of isopropyl alcohol, ethanol, ethylene glycol, n-butanol, and n-propanol.

3. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 2, characterized by, The mass ratio of water: organic alcohol: ionomer: catalyst is 9-50: 10-50: 8-12: 1, and the total solid content of the catalyst and the ionomer in the ink is 1%-20%.

4. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 1, characterized by, In step S1, the ink dispersion is performed by using a high-pressure homogenizer, the homogenization pressure is 800-1200 Pa, the motor frequency is 10-40 Hz, the homogenization time is 5-20 min, and the temperature is controlled to be between 5-10℃.

5. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 1, characterized by, In step S2, the diameter of the glassy carbon electrode is 5 mm, and the sampling amount of the ink is 2-5 μL; During the electrochemical performance testing, the testing is performed in an electrolyte, the electrolyte is a 1 mol / L H2SO4 solution, and nitrogen bubbling is performed for 30-60 min before the testing; The potential interval of the testing is 0.05 V-1.2 V relative to the reversible hydrogen electrode RHE, The scanning rate of the testing is 20 mV / s.

6. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 5, characterized by, The electrochemical performance testing is performed by using a three-electrode system, in which the reference electrode is a mercury-mercury electrode, and the counter electrode is a platinum sheet electrode.

7. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 1, characterized by, In step S3, the potential interval of the triangular wave potential cycle is 0.4 V-1.4 V relative to the reversible hydrogen electrode RHE, The scanning rate of the triangular wave potential cycle is 100 mV / s; During the accelerated aging, the ink is placed in an electrolyte, the electrolyte is a 1 mol / L H2SO4 solution, and the cycle number of the triangular wave potential cycle is 1000 cycles.

8. The method for evaluating the performance of the ink for the proton exchange membrane fuel cell according to claim 1, characterized by, In step S4, the half-peak width calculation comprises: Identify the peak current I of the hydrogen desorption peak peak ; Determining the baseline current I baseline ; Compute half-height current I half : I half = (I peak - I baseline ) / 2 + I baseline ; According to I half determining a left potential E left and a right potential E right on the CV curve; Compute half width E half : E half = |E left - E right | 9. The method of evaluating the performance of an ink for a proton exchange membrane fuel cell according to claim 1, characterized by, In step S5, if the half-peak width of the CV curve of the accelerated aging test increases, the electrochemical active area decay type of the ink is caused by ionomer agglomeration; If the half-peak width of the CV curve of the accelerated aging test decreases, the electrochemical active area decay type of the ink is caused by platinum particle detachment.

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