Electrolytic bath air chamber for electrolyzing water and alkaline electrolytic bath

Abstract

The invention relates to the field of hydrogen production through water electrolysis, and discloses an electrolytic bath air chamber for water electrolysis and an alkaline electrolytic bath, the electrolytic bath air chamber comprises a supporting net, an anode, an anode side separation net, a diaphragm, a cathode side separation net, a cathode and a supporting net which are sequentially overlapped, the anode side separation net and the cathode side separation net are pore plates with holes, grids with holes or layers with air permeability, and the supporting net is arranged between the anode side separation net and the cathode side separation net. The anode side separation net and the cathode side separation net are both made of non-metal alkali-resisting materials, the cathode side separation net and the anode side separation net are used for separating the electrode and the diaphragm, a gap for discharging gas on the electrode is generated, meanwhile, the compactness of lamination layers in the electrolytic cell such as the electrode and the supporting net is guaranteed, and the electrolytic cell is more stable in performance. The alkaline electrolytic cell for producing hydrogen by electrolyzing water has low contact resistance and bubble resistance, and the quality of obtained gas is guaranteed.

Description

Technical Field

[0001] This application relates to the field of hydrogen production by water electrolysis, and in particular to an electrolyzer gas chamber and an alkaline electrolyzer for water electrolysis. Background Technology

[0002] Hydrogen production through water electrolysis has garnered significant attention in recent years, particularly in the field of green energy. Alkaline water electrolysis, as a mature hydrogen production method, is widely used due to its low cost and high efficiency. However, optimizing the design of the electrolyzer to improve hydrogen production efficiency and product quality remains a key research focus in practical applications. Traditional alkaline electrolyzers consist of a multi-layered structure, including components such as a support mesh, electrodes, and a diaphragm. The interactions between these components directly affect the performance of the electrolysis process.

[0003] The existing alkaline electrolyzer gas chamber structure design sequentially includes a support mesh (papilla), electrodes, a diaphragm, electrodes, and another support mesh (papilla). During gas chamber assembly, to ensure good contact between the electrodes and the support mesh and minimize contact resistance, a relatively large pressure is applied during stacking. This often results in a tight fit between the electrodes and the diaphragm, causing some of the electrode mesh pores to be blocked by the diaphragm. This increases the bubble resistance and degrades the quality of the gas obtained from electrolysis.

[0004] Furthermore, the applicant also discovered that during long-term operation of the electrolytic cell, the corrosion of the electrode frame, circulation system, and electrodes by the alkaline solution leads to the incorporation of metal ions such as iron and nickel. These metal ions, under the influence of electrons, gradually deposit on the cathode surface, forming dendrites pointing from the cathode towards the anode. Due to the overlapping arrangement of the gas chambers in the electrolytic cell, the dendrite deposition and growth direction is perpendicular to the diaphragm. Therefore, over time, the dendrites will grow into the interior of the diaphragm.

[0005] Because dendrites are conductive, when a dendrite slightly embeds into the diaphragm, it will generate gas inside the diaphragm, reducing the diaphragm's gas-blocking effect and worsening the quality of the gas obtained in the gas chamber. Eventually, when the dendrites grow to a certain extent, they will come into direct contact with the anode, causing the diaphragm to burn through and further reducing the purity of oxygen.

[0006] The applicant has conducted research and improvements in this regard, hoping to solve the problem that the contact resistance and bubble resistance of the electrodes in the current alkaline electrolyzer for hydrogen production by water electrolysis are difficult to reach a low threshold at the same time, and the gas quality deteriorates significantly after long-term operation of the gas chamber. Summary of the Invention

[0007] In order to reduce the contact resistance and bubble resistance of the electrodes to a low threshold and obtain high-quality product gas for a long time during water electrolysis to produce hydrogen, an electrolytic cell gas chamber and an alkaline electrolytic cell for water electrolysis are provided.

[0008] The first inventive objective of this invention is achieved through the following technical solution: An electrolytic cell gas chamber for water electrolysis includes a stacked structure, comprising, in sequence, a stacked support mesh, an anode, an anode-side partition mesh, a diaphragm, a cathode-side partition mesh, a cathode, and a support mesh; Or it may include, in sequence, a stacked support mesh, anode, anode-side partition mesh, diaphragm, cathode, and support mesh; Alternatively, it may sequentially include a stacked support mesh, anode, diaphragm, cathode, cathode-side diaphragm, and support mesh. The cathode-side partition is a perforated plate, a perforated mesh, or a breathable layer; The anode-side partition is a perforated plate, a perforated mesh, or a breathable layer; Both the anode-side partition and the cathode-side partition are made of non-metallic alkali-resistant materials.

[0009] By adopting the above technical solution, this application adds the anode-side partition and cathode-side partition between the electrode and the diaphragm in the gas chamber structure of the electrolytic cell, which can support the electrode, make good contact between the electrode and the support mesh, and minimize the contact resistance. Meanwhile, the anode-side partition and the cathode-side partition are located between the electrode and the diaphragm to prevent the electrode from embedding into the diaphragm, and to form an exhaust and flushing space by relying on the pores and holes of the anode-side partition and the cathode-side partition themselves. The exhaust flushing space allows the bubbles generated by the electrodes to be quickly discharged, rather than embedded in the diaphragm and retained on the electrode surface. This prevents the bubbles from permeating into the diaphragm and causing gas mixing on both sides of the diaphragm, thereby reducing bubble resistance and ensuring the quality of the gas obtained from electrolysis. The rapid drainage of air bubbles on the electrodes also facilitates the flow of electrolyte on both sides of the diaphragm, balances the concentration difference of electrolyte on both sides of the diaphragm, reduces the polarization effect caused by the concentration difference, and lowers the overall resistance of the gas chamber of the electrolytic cell. The cathode-side diaphragm also allows the electrolyte to better flush the cathode surface facing the diaphragm, causing the metal crystals deposited on the cathode surface in the alkaline solution to peel off and inhibiting the formation of dendrites. Ultimately, the gas chamber of the electrolytic cell in this application has both low contact resistance and bubble resistance, and ensures the quality of the gas obtained from electrolysis.

[0010] Optional: The non-metallic alkali-resistant material is a polymer or its modified form.

[0011] Optionally, the non-metallic alkali-resistant material is one of polyphenylene sulfide, PTFE, PSU, PPSU, aramid and its modified materials, or basalt fiber.

[0012] Optionally, the modification direction of the modified material is acid and alkali resistance, high temperature resistance, or reinforcement.

[0013] By adopting the above technical solutions, polymer materials have better plasticity and processing properties than ceramic materials, making it more convenient to prepare anode-side and cathode-side spacers. Among them, polyphenylene sulfide, PTFE, PSU, and PPSU are currently the best choices in terms of performance.

[0014] Optionally, the anode-side partition and the cathode-side partition are perforated plates or perforated meshes with a hole size of 1 to 800 mesh and a thickness of 0.05 to 0.8 mm.

[0015] Optionally, the thickness of the cathode-side spacer is 0.25–0.35 mm.

[0016] Optionally, the thickness of the anode-side spacer is 0.05–0.2 mm.

[0017] By adopting the above technical solution, the electrolytic cell gas chamber of this application has superior low resistance performance and high product gas quality.

[0018] Optionally, the anode-side partition and the cathode-side partition are perforated plates and perforated meshes, and the surfaces of the cathode-side partition and the cathode-side partition are modified by hydrophilic treatment.

[0019] By adopting the above technical solution, the gas chamber of the electrolyzer for water electrolysis in this application achieves both low resistance performance and high product quality performance, which are both superior.

[0020] Optionally, the anode-side partition and the cathode-side partition are air-permeable layers, and the air permeability of the anode-side partition and the cathode-side partition is 4760-4840 L air / (m³) under a pressure difference of 0.2 MPa. 2 ·s).

[0021] The second objective of this invention is achieved through the following technical solution: An alkaline electrolyzer includes the gas chamber of an electrolyzer used for water electrolysis as described above.

[0022] By adopting the above technical solutions, alkaline electrolytic cells have low energy consumption, long service life, and produce high-quality products.

[0023] In summary, this application has at least the following beneficial effects: The electrolyzer gas chamber of this application has both low contact resistance and bubble resistance, and ensures the quality of the gas obtained from electrolysis. This allows the contact resistance and bubble resistance of the electrodes to drop to a low threshold during water electrolysis to produce hydrogen, thereby obtaining high-quality product gas, reducing the energy consumption of the electrolyzer, extending the service life of the electrolyzer, and improving product quality. Detailed Implementation

[0024] Example 1 An electrolytic cell gas chamber for water electrolysis includes a multi-layered stacked structure, comprising, in sequence, a support mesh, an anode, an anode-side partition mesh, a diaphragm, a cathode-side partition mesh, a cathode, and a support mesh.

[0025] The support mesh is made of metal, and its specifications are: thickness 0.5mm and mesh size 1 mesh.

[0026] The anode is made of one of the following materials: nickel-based, nickel-copper-iron alloy, or perovskite oxide. Here, it is a 50-mesh grid with a thickness of 0.7 mm. The cathode material here is Raney nickel alloy (aluminum content of 5% and nickel content of 95%).

[0027] The cathode is made of one of the following materials: nickel-based, platinum alloy, or metal-organic framework. Here, it is a 50-mesh grid with a thickness of 0.4 mm. The anode material is Raney nickel alloy (5% aluminum and 95% nickel) as an example.

[0028] The anode side septum is a perforated mesh fabric woven from polyphenylene sulfide yarn, with a thickness of 0.4 mm and a mesh count of 300.

[0029] The cathode side septum is a perforated mesh fabric woven from polyphenylene sulfide yarn, with a thickness of 0.4 mm and a mesh count of 300.

[0030] The diaphragm is a membrane made of polyphenylene sulfide fabric with a thickness of 1.4 mm.

[0031] Example 2 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that the anode-side partition is a perforated mesh cloth woven from PTFE thread, with a thickness of 0.4 mm and a mesh size of 300; the cathode-side partition is a perforated mesh cloth woven from PTFE thread, with a thickness of 0.4 mm and a mesh size of 300.

[0032] Example 3 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that the anode-side partition is a perforated mesh fabric woven from PSU thread, with a thickness of 0.4 mm and a mesh size of 300; the cathode-side partition is a perforated mesh fabric woven from PSU thread, with a thickness of 0.4 mm and a mesh size of 300.

[0033] Example 4 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that the anode-side partition is a perforated mesh fabric woven from PPSU thread, with a thickness of 0.4 mm and a mesh size of 300; the cathode-side partition is a perforated mesh fabric woven from PPSU thread, with a thickness of 0.4 mm and a mesh size of 300.

[0034] Example 5 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that the anode-side partition is a perforated ceramic plate with a thickness of 0.4 mm and a mesh size of 300; the cathode-side partition is a perforated ceramic plate with a thickness of 0.4 mm and a mesh size of 300.

[0035] Comparative Example 1 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that it does not have an anode-side partition and a cathode-side partition, i.e., its multi-layered stacked structure consists of a support mesh, an anode, a diaphragm, a cathode, and a support mesh.

[0036] Comparative Example 2 An electrolytic cell gas chamber for water electrolysis differs from Example 1 in that it uses nickel felt with 10μm nickel fiber sintering, a thickness of 0.4mm, and a porosity of 65% to replace the anode-side and cathode-side partitions.

[0037] Electrolytic cell gas chambers of Examples 1-5 and Comparative Examples 1-2 were assembled and electrolyzed.

[0038] Assembly Electrolysis Test: The number of gas chambers in the stacked electrolytic cell is 50, and the electrolyte is a 12.8 wt% sodium hydroxide solution. The voltage of the cell is measured at a current density of 3000 A per square meter, and the voltage of a single gas chamber is calculated. Under the same current, the higher the voltage, the higher the resistance.

[0039] The hydrogen content in the oxygen obtained by electrolysis was detected using an Acer CI-PC56 detector and recorded as the initial hydrogen content in the oxygen.

[0040] Long-term production gas quality testing: An assembled electrolytic cell was used for testing. The cell was kept intact, and the electrolyte was circulated, with deionized water added to maintain a concentration of 12.8 ± 0.1 wt% when circulated back into the cell. The cell was operated continuously for 168 hours. The hydrogen content in the obtained oxygen was then measured again using a CI-PC56 analyzer. The test results are expressed as the voltage of a single electrolytic cell gas chamber and the hydrogen content in the oxygen, denoted as the hydrogen content in the long-term produced oxygen.

[0041] Table 1. Detection results of Examples 1-5 and Comparative Examples 1-2 The voltage and initial hydrogen content in the gas chamber of a single electrolyzer were compared between Examples 1-5 and Comparative Examples 1-2.

[0042] The voltage of the individual electrolytic cell gas chamber in Examples 1-5 is significantly lower than that in Comparative Example 1. Under constant current conditions, the resistance of the individual electrolytic cell gas chamber in Examples 1-5 is significantly lower than that in Comparative Example 1. At the same time, the hydrogen content in the initial oxygen of the products in Examples 1-5 is significantly lower than that in Comparative Example 1.

[0043] The reason is that in Examples 1-5, the anode-side and cathode-side partitions of this application are added between the electrodes and the diaphragm in the gas chamber structure of the electrolytic cell. This supports the electrodes, ensuring good contact between the electrodes and the support mesh, and minimizing contact resistance. At the same time, the anode-side and cathode-side partitions are located between the electrodes and the diaphragm, preventing the electrodes from embedding into the diaphragm. They also form an exhaust flushing space based on the pores and holes of the anode-side and cathode-side partitions themselves. This exhaust flushing space allows the bubbles generated by the electrodes to be quickly discharged, rather than being embedded in the diaphragm and remaining on the electrode surface. This prevents bubbles from permeating into the diaphragm and causing gas mixing on both sides of the diaphragm, thereby reducing bubble resistance and ensuring the quality of the gas obtained from electrolysis. The electrolyte flows on both sides of the diaphragm, balancing the concentration difference of the electrolyte on both sides of the diaphragm, reducing the polarization effect caused by the concentration difference, and reducing the overall resistance of the gas chamber of the electrolytic cell.

[0044] The voltage of a single electrolytic cell gas chamber in Examples 1-5 is lower than that in Comparative Example 2, and the resistance of a single electrolytic cell gas chamber in Examples 1-5 is lower than that in Comparative Example 2 under constant current conditions; at the same time, the hydrogen content in the initial oxygen of the products in Examples 1-5 is lower than that in Comparative Example 2.

[0045] The reason is that nickel felt is made by sintering and pressing nickel fibers, which are conductive. When the electrolytic cell is working, the surface of the nickel fibers will generate gas, just like the electrodes. Therefore, gas will be generated on the surface and inside of the nickel felt, making it impossible to provide a space for the rapid exhaust and flushing of gas generated by the electrodes. At the same time, nickel metal has poor hydrophilicity, and it is difficult to actively wet and expel gas bubbles no matter how the alkaline solution is adjusted. Therefore, there will always be an accumulation of bubbles inside the nickel felt, which is not conducive to the flushing of the electrolyte and increases the gas content between the diaphragm and the electrode.

[0046] The changes in hydrogen content in the initial oxygen and the hydrogen content in the long-term produced oxygen were compared in Examples 1-5 and Comparative Examples 1-2. In Examples 1-5, the hydrogen content in the long-term produced oxygen did not show a significant increase compared to the initial oxygen content; in Comparative Example 1, the hydrogen content in the long-term produced oxygen showed a significant increase compared to the initial oxygen content; and in Comparative Example 2, the hydrogen content in the long-term produced oxygen showed a significant increase compared to the initial oxygen content, and the increase was greater than that in Comparative Example 1.

[0047] The reason is that the cathode-side diaphragm, in addition to separating the cathode from the diaphragm and allowing other cathode components to be quickly discharged, has the non-conductive property that prevents metal from depositing on the cathode-side diaphragm. At the same time, the exhaust flushing space of the cathode-side diaphragm also helps the electrolyte to better flush the cathode surface facing the diaphragm, causing the metal crystals deposited on the cathode surface in the alkaline solution to peel off and inhibiting the formation of dendrites. In contrast, the gas quality of Comparative Example 2 is more deteriorated than that of Comparative Example 1 (the hydrogen content in the long-term oxygen production is significantly increased). This is because the shape of the nickel felt makes it easier for nickel and iron ions to dissolve, which exacerbates the formation of dendrites.

[0048] In summary, the electrolytic cell gas chamber of this application has both low contact resistance and bubble resistance, and ensures the quality of the gas obtained from electrolysis.

[0049] Examples 6-20 An electrolytic cell gas chamber for water electrolysis includes a multi-layered stacked structure, consisting of a support mesh, an anode, an anode-side partition mesh, a diaphragm, a cathode-side partition mesh, a cathode, and a support mesh. The difference from Embodiment 1 lies in the different parameters of the anode-side partition mesh and the cathode-side partition mesh. Details are shown in the table below.

[0050] Table 2. Specific parameters of anode-side screen and cathode-side screen in Examples 6-20 Example 21 An electrolytic cell gas chamber for water electrolysis includes a multi-layered stacked structure, comprising, in sequence, a support mesh, an anode, an anode-side partition mesh, a diaphragm, a cathode, and another support mesh.

[0051] The support mesh is made of metal, and its specifications are: thickness 0.5mm and mesh size 1 mesh.

[0052] The anode is made of one of the following materials: nickel-based, nickel-copper-iron alloy, or perovskite oxide. Here, it is a 50-mesh grid with a thickness of 0.7 mm.

[0053] The cathode is made of one of the following materials: nickel-based, platinum alloy, or metal-organic framework. Here, it is a 50-mesh grid with a thickness of 0.4 mm.

[0054] The anode side septum is a perforated plate or perforated mesh made of polyphenylene sulfide, with a thickness of 0.4 mm and a mesh size of 300.

[0055] The diaphragm is a membrane made of polyphenylene sulfide fabric with a thickness of 1.4 mm.

[0056] Example 22 An electrolytic cell gas chamber for water electrolysis includes a multi-layered stacked structure, comprising, in sequence, a support mesh, an anode, a diaphragm, a cathode-side diaphragm, a cathode, and a support mesh.

[0057] The support mesh is made of metal, and its specifications are: thickness 0.5mm and mesh size 1 mesh.

[0058] The anode is made of one of the following materials: nickel-based, nickel-copper-iron alloy, or perovskite oxide. Here, it is a 50-mesh grid with a thickness of 0.7 mm.

[0059] The cathode is made of one of the following materials: nickel-based, platinum alloy, or metal-organic framework. Here, it is a 50-mesh grid with a thickness of 0.4 mm.

[0060] The cathode-side septum is a perforated plate or perforated mesh made of polyphenylene sulfide, with a thickness of 0.4 mm and a mesh size of 300.

[0061] The diaphragm is a membrane made of polyphenylene sulfide fabric with a thickness of 1.4 mm.

[0062] Example 23 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that the anode-side partition and the cathode-side partition have undergone hydrophilic modification treatment.

[0063] The hydrophilic modification process is as follows: The anode-side and cathode-side spacers were immersed in a 20wt% ethanol aqueous solution and ultrasonically cleaned for 30 minutes, then rinsed three times with deionized water, and vacuum dried at 76℃ to constant weight. Prepare an 8% (w / v) potassium persulfate aqueous solution, immerse the anode-side and cathode-side screens in the 8% (w / v) potassium persulfate aqueous solution, and treat with ultrasonic assistance for 30 min; Remove the anode-side and cathode-side partitions and blot away any excess solution from their surfaces; The soaked fibers were transferred to a reaction vessel, and the reactor was heated under nitrogen protection to 65°C and held for 10 minutes. Maleic anhydride was dissolved in DMF at a concentration of 12% (w / v) and slowly dripped into the reaction vessel until the anode-side and cathode-side screens were submerged. The temperature was maintained at 65°C, and the reaction was carried out for 6 hours. Cool the reactor to room temperature, add a 0.1% (w / v) hydroquinone solution (the amount of hydroquinone is 0.1 wt% of maleic anhydride), circulate the liquid phase until it is thoroughly mixed, and then let it stand for 10 minutes. Remove the anode-side and cathode-side spacers and ultrasonically clean them sequentially with acetone and deionized water for 20 minutes to remove ungrafted monomers and homopolymers. The anode-side and cathode-side spacers were then placed in a vacuum drying oven at 60°C and dried for 12 hours until the mass was constant, resulting in hydrophilic modified anode-side and cathode-side spacers.

[0064] Example 24 An electrolytic cell gas chamber for water electrolysis, differing from Example 1 in that its anode-side and cathode-side partitions are permeable layers with a permeability of 4680 L air / (m³) under a pressure difference of 0.2 MPa. 2 ·s).

[0065] Example 25 An electrolytic cell gas chamber for water electrolysis, differing from Example 1 in that its anode-side and cathode-side partitions are permeable layers with a permeability of 4760 L air / (m³) under a pressure difference of 0.2 MPa. 2 ·s).

[0066] Example 26 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that its anode-side and cathode-side partitions are permeable layers with a permeability of 4820 L air / (m³) under a pressure difference of 0.2 MPa. 2 ·s).

[0067] Example 27 An electrolytic cell gas chamber for water electrolysis differs from that in Example 1 in that its anode-side and cathode-side partitions are permeable layers with a permeability of 4840 L air / (m³) under a pressure difference of 0.2 MPa. 2 ·s).

[0068] Example 28 An electrolytic cell gas chamber for water electrolysis, differing from Example 1 in that its anode-side and cathode-side partitions are permeable layers with a permeability of 1900 L air / (m³) under a pressure difference of 0.2 MPa. 2 ·s).

[0069] The electrolytic cell gas chambers of Examples 6-28 were subjected to assembly electrolysis tests and long-term production gas quality tests.

[0070] The test results are shown in the table below.

[0071] Table 3. Detection results of Examples 6-28 Referring to Tables 1 and 3, comparing Examples 1, 6-10, and Comparative Example 1, the voltage of a single electrolytic cell in Examples 1 and 6-10 is significantly lower than that in Comparative Example 1. Under constant current conditions, the resistance of a single electrolytic cell in Examples 1 and 6-10 is significantly lower than that in Comparative Example 1. Simultaneously, the hydrogen content in the initial oxygen in Examples 1 and 6-10 is significantly lower than that in Comparative Example 1. Combining Examples 21 and 22, Example 21 only installs an anode-side spacer between the anode and the diaphragm, while Example 22 only installs a cathode-side spacer between the cathode and the diaphragm.

[0072] Although the voltage of a single electrolytic cell gas chamber in Examples 21 and 22 is greater than that of the better examples in Examples 1 and 6-10, it is still significantly lower than that in Comparative Example 1. Although the hydrogen content in the initial oxygen in Examples 21 and 22 was greater than that in Examples 1 and 6-10 (which were the better ones), it was still significantly lower than that in Comparative Example 1. Therefore, this application adds the anode-side partition and cathode-side partition between the electrode and the diaphragm in the gas chamber structure of the electrolytic cell. On the one hand, it can support the electrode, so that the electrode can have good contact with the support mesh and minimize the contact resistance. On the other hand, it avoids embedding the electrode into the diaphragm and forms an exhaust space between the electrode and the diaphragm, so that the bubbles on the electrode can be quickly discharged, rather than embedding the bubbles into the diaphragm and retaining them on the electrode surface. This reduces the bubble resistance and prevents the bubbles from permeating into the diaphragm, causing gas mixing on both sides of the diaphragm and reducing the quality of the gas obtained from electrolysis. In addition, the rapid drainage of air bubbles on the electrodes is also beneficial to the flow of electrolyte on both sides of the diaphragm, balancing the concentration difference of electrolyte on both sides of the diaphragm, reducing the polarization effect caused by the concentration difference, and reducing the overall resistance of the gas chamber of the electrolytic cell. Ultimately, this results in the electrolytic cell gas chamber of this application having both low contact resistance and bubble resistance, while ensuring the quality of the gas obtained from electrolysis.

[0073] Further analysis of Examples 1, 6-10 reveals that in a single example, the mesh count of the anode-side partition and the cathode-side partition is equal. However, in Examples 6-8, 1, and 9-10, the mesh count of the anode-side partition and the cathode-side partition gradually increases from 1 mesh to 800 mesh, while the mesh size gradually decreases.

[0074] In Examples 6-8, 1, and 9, the voltage of a single electrolytic cell gas chamber gradually decreased as the mesh size increased; in Examples 9-10, the voltage of a single electrolytic cell gas chamber gradually increased as the mesh size increased.

[0075] In Examples 6-8 and Example 1, the hydrogen content in the initial oxygen gradually decreased as the mesh size increased; in Examples 1 and Examples 9-10, the hydrogen content in the initial oxygen gradually increased as the mesh size increased.

[0076] The reason is that as the mesh size increases, the pores shrink continuously, making the separation gap between the electrode and the diaphragm more stable and the bubbles easier to expel. After the pores shrink to a certain threshold, although the bubble expulsion rate is still faster than that of Comparative Example 1, it will decrease compared to the embodiment with a smaller mesh size, and will cause some obstruction to the flow of electrolyte on both sides of the diaphragm. Therefore, the voltage of the gas chamber of a single electrolytic cell and the hydrogen content in the initial oxygen will increase.

[0077] Therefore, the mesh size of the anode-side and cathode-side partitions in this application can be increased from 10 mesh to 800 mesh, with 50 to 600 mesh being more preferred.

[0078] This application also investigates the effect of the thickness of the anode-side and cathode-side spacers.

[0079] In conjunction with Examples 1 and 11-15, the thickness of the anode-side spacer and the thickness of the cathode-side spacer are equal in each of the examples 1 and 11-15. The thickness of the anode-side spacer and the thickness of the cathode-side spacer gradually increase from Example 11 to Example 12 to Example 13 to Example 14 to Example 15.

[0080] The voltage of the individual electrolytic cell gas chambers in the test results, from low to high, are Example 13, Example 1, Example 12, Example 11, Example 14, and Example 15. The hydrogen content in the initial oxygen, from low to high, is Example 1, Example 13, Example 12, Example 11, Example 14, and Example 15. Meanwhile, the voltage of the individual electrolytic cell gas chambers and the hydrogen content in the initial oxygen in Examples 11 to 15 are all lower than those in Comparative Example 1.

[0081] Therefore, when the cathode-side septum, the cathode-side septum is a perforated plate or a perforated mesh with uniform thickness, the thickness can be 0.05 to 0.8 mm, with 0.1 to 0.4 mm being the most preferred.

[0082] In conjunction with Examples 16-20, the thickness of the anode-side partition and the cathode-side partition are different in Examples 16-20. The voltage of a single electrolytic cell gas chamber from low to high is Example 20, Example 16, Example 19, Example 17, and Example 18. The hydrogen content in the initial oxygen from low to high is Example 20, Example 16, Example 19, Example 17, and Example 18.

[0083] Furthermore, the performance of Examples 16, 17, 19, and 20 is close to or better than that of Example 1. Therefore, anode-side and cathode-side spacers of different thicknesses may bring better low resistance performance and better product quality. The thickness of the cathode-side spacer is 0.25-0.35 mm, and the thickness of the anode-side spacer is 0.05-0.2 mm.

[0084] This application also studies the hydrophilic modification of the anode-side partition and the cathode-side partition. For example, Example 23 is an improvement on Example 1. The voltage of a single electrolytic cell gas chamber and the hydrogen content in the initial oxygen in Example 23 are lower than those in Example 23. Therefore, the hydrophilic modification of the anode-side partition and the cathode-side partition in this application helps to improve the performance of the electrolytic cell gas chamber in this application.

[0085] In this application, the anode-side partition and the cathode-side partition can also be air-permeable layers without fixed-shape holes or regular hole distribution, which have air permeability, as in Examples 24 to 28.

[0086] Comparing Examples 24-28 with Comparative Example 1, it can be seen that the voltage of a single electrolytic cell gas chamber in Examples 26-28 is significantly lower than that in Comparative Example 1, the hydrogen content in the initial oxygen in Examples 24-28 is significantly lower than that in Comparative Example 1, and the performance of Examples 25-27 is superior to that of Examples 24 and 28. Therefore, in this application, in addition to perforated plates and perforated grids, the anode-side and cathode-side partitions can also be made of permeable layers without fixed-shape holes or regular hole distribution, and the permeability of the permeable layer is 4760-4840 L air / (m³) under a pressure difference of 0.2 MPa. 2 It is better when ·s).

[0087] Example 29 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that the anode-side partition and cathode-side partition are made of PTFE, specifically Daikin F-104 from Japan.

[0088] Example 30 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that the material of its anode-side partition and cathode-side partition is PSU (ordinary bisphenol A type PS), and the PSU is Solvay P-17000.

[0089] Example 31 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that the anode-side partition and cathode-side partition are made of PPSU, and PSU is the grade of Youju New Materials: F1350.

[0090] Example 32 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that the anode-side partition and cathode-side partition are made of PTFE, specifically Daikin M532 from Japan.

[0091] Example 33 An electrolytic cell gas chamber for water electrolysis differs from Example 1 in that the anode-side and cathode-side partitions are made of an acid and alkali resistant material made of a blend of PTFE and PSU (ordinary bisphenol A type PS). The PSU is Solvay P-17000, and the PTFE is Daikin M532 from Japan, with a blending mass ratio of 1:0.3.

[0092] Example 34 An electrolyzer gas chamber for water electrolysis, which differs from Example 1 in that the anode-side partition and cathode-side partition are made of light calcium carbonate reinforced modified PTFE, and the amount of light calcium carbonate added is 8.2 wt% of the weight.

[0093] Example 35 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that the anode-side partition and cathode-side partition are made of aramid fiber, specifically aramid 1414.

[0094] Example 36 An electrolytic cell gas chamber for water electrolysis, which differs from Example 1 in that its anode-side partition and cathode-side partition are made of basalt fiber with a diameter of 10±0.5μm.

[0095] Examples 29 to 34 were tested, and the test results are shown in the table below.

[0096] Table 4. Detection results of Examples 29-34 Comparing Example 1, Comparative Example 1, and Examples 29-32, it can be seen that when using materials other than polyphenylene sulfide as the materials for making the cathode-side spacer or anode-side spacer, PTFE, PPSU, PTFE, and PSU materials can also be used. The cathode-side spacer and anode-side spacer made therefrom can also play a functional role, so that the voltage of a single electrolytic cell gas chamber in Examples 29-32 is similar to that in Example 1, and the hydrogen content in the initial oxygen and the hydrogen content in the long-term produced oxygen are significantly lower than those in Comparative Example 1.

[0097] This application also modifies the above materials, for example, Example 33, which obtains the dual advantages of strength and acid and alkali resistance, and Example 34, which enhances hardness and avoids dendrite growth and damage to the wall surface. In the test results, the voltage of a single electrolytic cell gas chamber in Examples 33 and 34 is similar to that in Example 1, and the hydrogen content in the initial oxygen and the hydrogen content in the long-term produced oxygen in Examples 33 and 34 are significantly lower than those in Comparative Example 1.

[0098] Furthermore, other materials can be used to manufacture the cathode-side or anode-side partition in this application, such as aramid fiber in Example 35 and basalt fiber in Example 36. In the test results, the voltage of a single electrolytic cell gas chamber in Examples 35-36 was significantly lower than that in Comparative Example 1, and the resistance of a single electrolytic cell gas chamber in Examples 35-36 under constant current conditions was significantly lower than that in Comparative Example 1; similarly, the hydrogen content in the initial oxygen in Examples 35-36 was significantly lower than that in Comparative Example 1, and the hydrogen content in the long-term produced oxygen in Examples 35-36 was also lower than that in Comparative Example 1.

[0099] In summary, the materials used for the cathode-side and anode-side spacers in this application are non-conductive, non-metallic, alkali-resistant materials, with organic polymer materials being the preferred choice. Among these, PTFE, PPSU, PSU, PPS, aramid materials, and their modified materials are preferred options.

[0100] Example 37 An alkaline electrolyzer includes two end plates and multiple point electrolyzer chambers sandwiched between the two end plates. The multiple electrolyzer chambers are stacked together. The electrolyzer chambers are one of those described in Examples 1 to 34.

[0101] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of protection claimed by the present invention, they are protected by patent law.

Claims

1. A gas chamber for an electrolytic cell used in water electrolysis, characterized in that, It includes a composite structure, The sequence is as follows: stacked support mesh, anode, anode-side partition mesh, diaphragm, cathode-side partition mesh, cathode, and support mesh; Or it may include, in sequence, a stacked support mesh, anode, anode-side partition mesh, diaphragm, cathode, and support mesh; Alternatively, it may sequentially include a stacked support mesh, anode, diaphragm, cathode, cathode-side diaphragm, and support mesh. The anode-side partition is a perforated plate, a perforated mesh, or a breathable layer; The cathode-side partition is a perforated plate, a perforated mesh, or a breathable layer; Both the anode-side partition and the cathode-side partition are made of non-metallic alkali-resistant materials.

2. The gas chamber of an electrolytic cell for water electrolysis according to claim 1, characterized in that, The non-metallic alkali-resistant material is a polymer and its modified form.

3. The gas chamber of an electrolytic cell for water electrolysis according to claim 1, characterized in that, The non-metallic alkali-resistant material is one of polyphenylene sulfide, PTFE, PSU, PPSU, aramid and its modified materials, or basalt fiber.

4. The gas chamber of an electrolytic cell for water electrolysis according to claim 2, characterized in that, The modification direction of the modified material is acid and alkali resistance, high temperature resistance, or reinforcement.

5. The gas chamber of an electrolytic cell for water electrolysis according to claim 1, characterized in that, The anode-side partition and cathode-side partition are perforated plates and perforated meshes, with hole sizes ranging from 1 to 800 mesh and thicknesses from 0.05 to 0.4 mm.

6. The gas chamber of an electrolytic cell for water electrolysis according to claim 5, characterized in that, The thickness of the cathode-side partition is 0.25~0.35mm.

7. The gas chamber of an electrolytic cell for water electrolysis according to claim 5, characterized in that, The thickness of the anode-side spacer is 0.05~0.2mm.

8. The gas chamber of an electrolytic cell for water electrolysis according to claim 1, characterized in that, The cathode-side partition is a perforated plate or a perforated mesh, and the surface of the cathode-side partition is modified by hydrophilic treatment.

9. The gas chamber of an electrolytic cell for water electrolysis according to claim 1, characterized in that, The anode-side partition and the cathode-side partition are air-permeable layers, and the air permeability of the anode-side partition and the cathode-side partition is 4760~4840 L air / (m²·s) under a pressure difference of 0.2MPa.

10. An alkaline electrolytic cell, characterized in that, Includes the gas chamber of the electrolyzer for water electrolysis as described in any one of claims 1 to 9.

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