Membrane-free electrolytic water hydrogen production electrolytic tank based on chemical looping circulation and operation method

Abstract

The invention relates to a membrane-free water electrolysis hydrogen production electrolytic cell based on chemical looping circulation and an operation method. The electrolytic cell comprises a first end plate and a second end plate which are connected with an external power source, at least one bipolar plate is arranged between the two end plates, and small electrolysis chambers are formed between the two end plates and the bipolar plates and between the two adjacent bipolar plates respectively; each small electrolysis chamber is internally provided with a functional assembly, each functional assembly comprises a bifunctional electrode, a porous partition plate and an oxygen carrier electrode which are sequentially attached, and when the bifunctional electrodes and the oxygen carrier electrodes are used in a matched mode, catalytic hydrogen evolution and catalytic oxygen evolution can be conducted under different working conditions to adapt to power fluctuation and intermittency of renewable energy sources; the application potential of off-grid hydrogen production is realized. The operation method comprises the step of realizing step-by-step or continuous production of hydrogen and oxygen under different working conditions through cooperative energy supply of a temperature field and an electric field.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production by water electrolysis, and in particular to a membraneless water electrolysis hydrogen production electrolyzer based on chemical chain circulation and an operation method. Background Art

[0002] Hydrogen is widely regarded as an ideal green energy carrier due to its high energy density and environmentally friendly properties. However, more than 90% of global hydrogen production currently relies on fossil fuels, which leads to a large amount of carbon dioxide emissions and is not conducive to addressing climate change. To achieve a carbon-free economy, water electrolysis hydrogen production technology is particularly critical, especially when renewable energy sources such as solar energy, wind energy, hydropower and geothermal energy are used to provide electricity. This hydrogen production method can not only effectively store excess electricity from renewable energy, but also solve the problem of discontinuity in the temporal and spatial distribution of renewable energy, thereby promoting the sustainable supply and distribution of energy. Traditional membrane water electrolysis hydrogen production technology faces multiple challenges, including safety hazards caused by the mixing of hydrogen and oxygen, the high cost of membrane materials, and efficiency loss caused by membrane resistance. The above problems limit the system capacity and hinder the large-scale application of water electrolysis hydrogen production. Although hundreds of new membrane materials have been developed by domestic and foreign research institutions in recent years, due to the limitations of the ion transport activity and physicochemical stability of the membrane, membrane water electrolysis hydrogen production technology has always been difficult to break through the contradiction between safety, large capacity and low energy consumption.

[0003] In response to this, membraneless water electrolysis technology came into being. It achieves the spatiotemporal decoupling of hydrogen and oxygen evolution reactions through the redox cycle of oxygen carriers (i.e., chemical chain cycle), and has advantages such as intrinsic safety and energy efficiency. However, existing membraneless electrolysis technology has problems such as low integration of electrolyzer structure and low efficiency of hydrogen and oxygen production. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a membraneless water electrolysis hydrogen production electrolyzer based on chemical chain circulation and an operation method, the purpose of which is to improve the integration of the electrolyzer structure and improve the hydrogen production efficiency.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention provides a membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle, the electrolyzer comprises a first end plate and a second end plate respectively connected to an external power supply, the first end plate and the second end plate are connected to form a whole, at least one bipolar plate is arranged inside, and electrolysis chambers are respectively formed between the two end plates and the bipolar plates, and between two adjacent bipolar plates;

[0007] Each of the electrolysis cells is provided with a functional component, the functional component comprising a bifunctional electrode, a porous partition and an oxygen carrier electrode which are bonded in sequence, the bifunctional electrode being used for catalytic hydrogen evolution under a first working condition and catalytic oxygen evolution under a second working condition; the polarity of the external power supply is opposite under the first working condition and the second working condition;

[0008] A gasket is sleeved on the outer side of the functional component;

[0009] Except for the gasket sleeved on the outer side of the functional component in the electrolysis chamber close to the first end plate, which is not provided with the first upper channel, the upper parts of the other gaskets are provided with the first upper channel along the thickness direction;

[0010] A first lower channel is provided at the lower part of all gaskets;

[0011] The bipolar plate is provided with first flow channel areas on both sides, and the first flow channel areas on both sides are electrically connected to the oxygen carrier electrode and the bifunctional electrode respectively through conductive columns distributed thereon, so that a plurality of electrolytic chambers are connected in series in sequence;

[0012] A second upper channel is provided at the upper part of the bipolar plate along the thickness direction, and a second lower channel is provided at the lower part along the thickness direction; a first flow guide channel communicating with the second upper channel is provided at the upper part of the first wave flow channel area, and a second flow guide channel communicating with the second lower channel is provided at the lower part of the first flow channel area;

[0013] The first lower channel and the second lower channel are alternately connected in sequence to form an electrolyte input channel, and the electrolyte in the electrolyte input channel flows into each electrolytic chamber through the second flow guide channel;

[0014] The first upper channel and the second upper channel are alternately connected in sequence to form a gas-liquid output channel, and the electrolysis products and electrolyte in each electrolysis chamber flow out from the first flow guide channel to the gas-liquid output channel;

[0015] A second flow channel area is provided inside the first end plate, which is connected to the dual-function electrode through a conductive column, and an input port is provided on the upper thickness direction of the first end plate;

[0016] A third flow channel area is provided inside the second end plate, which is connected to the oxygen carrier electrode through a conductive column, and an output port is provided on the second end plate in the thickness direction;

[0017] The upper portion of the third flow channel region is provided with a first flow guide channel connected to the output port.

[0018] A second flow channel communicating with the electrolyte input channel is provided at the lower part of the third flow channel area;

[0019] The inlet end of the electrolyte input channel is connected to the input port, and the outlet end of the gas-liquid output channel is connected to the output port.

[0020] Further technical solutions are:

[0021] The first flow guide channel and the second flow guide channel are located on the side of the bipolar plate and the second end plate close to the oxygen carrier electrode.

[0022] The depth of the first flow guide channel and the second flow guide channel is no more than half of the thickness of the bipolar plate.

[0023] The material of the bifunctional electrode includes one of metal phosphide, metal sulfide, metal carbide, metal nitride and metal oxide.

[0024] The size of the bifunctional electrode is not greater than that of the oxygen carrier electrode.

[0025] The oxygen carrier electrode is an electrode with nickel hydroxide as a main component.

[0026] The porous partition is a hollow or non-hollow sheet structure, and is made of insulating porous material.

[0027] The present invention also provides a method for operating the membraneless water electrolysis hydrogen production electrolyzer based on chemical chaining cycle, including step-by-step production of hydrogen and oxygen, which includes:

[0028] By controlling the external power switch to switch the operating conditions of the electrolyzer, at least one of the electrolyzers is operated alternately in the first operating condition and the second operating condition in sequence, so as to realize the step-by-step production of hydrogen and oxygen in the same space;

[0029] The first working condition is: in an electrolyte at 20-50°C, the first end plate and the second end plate are connected to the negative electrode and the positive electrode of an external power supply respectively, and after power is turned on, the bifunctional electrode promotes the electrolysis of water to produce hydrogen, the active components in the oxygen carrier electrode are oxidized to oxidized oxygen carriers, and hydrogen is output from the gas-liquid output channel;

[0030] The second working condition is: in an electrolyte at 50-100°C, the polarity of the external power supply is reversed, that is, the first end plate and the second end plate are respectively connected to the positive and negative electrodes of the external power supply, and after power is turned on, the bifunctional electrode promotes the electrolysis of water to produce oxygen, and the oxidized oxygen carrier in the oxygen carrier electrode is partially spontaneously reduced under the action of the temperature field and is completely reduced under the action of the electric field, and oxygen is output from the gas-liquid output channel.

[0031] Further technical solutions are:

[0032] The operation method also includes continuous production of hydrogen and oxygen, which includes:

[0033] Using at least one of the electrolytic cells to form a first group of electrolytic cells, and using at least one of the electrolytic cells to form a second group of electrolytic cells;

[0034] By controlling the external power switch to switch the operating conditions of the electrolytic cells, the first group of electrolytic cells operates alternately under the first operating condition and the second operating condition, and at the same time, the second group of electrolytic cells operates alternately under the second operating condition and the first operating condition, thereby realizing continuous production of hydrogen and oxygen in different spaces.

[0035] The electrolyte is KOH or NaOH solution.

[0036] The beneficial effects of the present invention are as follows:

[0037] 1. The present invention introduces a dual-function electrode into the electrolyzer, which can catalyze not only the hydrogen evolution reaction but also the oxygen evolution reaction, thereby improving the integration of the electrolyzer system. In addition, the use of precious metal materials is avoided, and the equipment cost is significantly reduced.

[0038] 2. The present invention realizes step-by-step hydrogen and oxygen production in the same electrolyzer through the redox cycle of the oxygen carrier electrode. After coupling with the bifunctional electrode, hydrogen and oxygen can be produced under different voltage conditions, which greatly adapts to the power volatility and intermittency of renewable energy and has the potential for off-grid hydrogen production.

[0039] 3. The present invention supplies energy to the electrolysis system through the coupling of temperature field and electric field. In the hydrogen production stage, the oxygen carrier is oxidized under the action of the low-temperature electric field, which inhibits the occurrence of competitive oxygen evolution reaction. In the oxygen production stage, the oxidized oxygen carrier is reduced under the joint action of the temperature field and the electric field, ensuring the complete regeneration of the oxygen carrier, significantly improving the regeneration rate of the oxygen carrier, solving the rate limitation problem of the oxygen evolution reaction, and greatly improving the hydrogen production cycle efficiency. In addition, due to the effect of the temperature field, the oxygen production voltage is greatly reduced, which significantly reduces the overall hydrogen production cost.

[0040] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the structure of an electrolyzer for producing hydrogen by membraneless water electrolysis according to an embodiment of the present invention.

[0042] Figure 2 Schematic diagram of the structure of the gasket according to an embodiment of the present invention.

[0043] Figure 3 Schematic diagram of the structure of a bipolar plate according to an embodiment of the present invention.

[0044] Figure 4 A schematic diagram of the first end plate structure of an embodiment of the present invention

[0045] Figure 5 Schematic diagram of the structure of the second end plate of an embodiment of the present invention.

[0046] Figure 6 The cell voltage curve obtained from the single electrolysis chamber test of the comparative example and embodiment 2 of the present invention.

[0047] In the figure: 1. electrolysis chamber; 2. bipolar plate; 3. electrolyte input channel; 4. gas-liquid output channel; 5. first end plate; 6. second end plate; 7. first flow channel; 8. second flow channel; 9. nut; 10. bolt; 101. bifunctional electrode; 102. porous partition; 103. oxygen carrier electrode; 104. gasket; 201. first flow channel area; 301. first lower channel; 302. second lower channel; 401. first upper channel; 402. second upper channel; 501. second flow channel area; 601. third flow channel area; 3011. input port; 4021. output port. DETAILED DESCRIPTION

[0048] The specific implementation of the present invention is described below with reference to the accompanying drawings.

[0049] Example 1

[0050] like Figure 1 As shown, a membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle in this embodiment comprises a first end plate 5 and a second end plate 6 respectively connected to an external power source, the first end plate 5 and the second end plate 6 are connected to form a whole, one or more bipolar plates 2 are arranged inside, and electrolysis chambers 1 are respectively formed between two end plates and the adjacent bipolar plates 2, and between two adjacent bipolar plates 2;

[0051] Each electrolysis cell is provided with a functional component, which includes a bifunctional electrode 101, a porous partition 102 and an oxygen carrier electrode 103 which are sequentially attached. The bifunctional electrode 101 is used to catalyze hydrogen evolution under a first working condition and catalyze oxygen evolution under a second working condition. The polarity of the external power supply is opposite under the first working condition and the second working condition.

[0052] A gasket 104 is sleeved on the outer side of the functional component;

[0053] See also Figure 1 and Figure 2 Except for the gasket 104 sleeved on the outer side of the functional component in the electrolysis chamber 1 close to the first end plate 5, which is not provided with the first upper channel 401, the upper parts of the other gaskets 104 are provided with the first upper channel 401 along the thickness direction; the lower parts of all the gaskets 104 are provided with the first lower channel 301;

[0054] The two sides of the bipolar plate 2 are respectively connected to the oxygen carrier electrode 103 and the bifunctional electrode 101 of two adjacent electrolytic chambers to form a flow channel, so that the multiple electrolytic chambers 1 are connected in series in sequence.

[0055] For details, see Figure 1 and Figure 3 A first wavy guide surface 201 is provided on both sides of the bipolar plate 2. The first wavy guide surfaces 201 on both sides are electrically connected to the oxygen carrier electrode 103 and the bifunctional electrode 101 through conductive columns distributed thereon, so that multiple electrolysis chambers 1 are connected in series in sequence.

[0056] The upper part of the bipolar plate 2 is provided with a second upper channel 402 along the thickness direction, and the lower part is provided with a second lower channel 302 along the thickness direction; the upper part of the first wavy guide surface 201 is provided with a first guide channel 7 communicating with the second upper channel 402; the lower part of the first wavy guide surface 201 is provided with a second guide channel 8 communicating with the second lower channel 302;

[0057] like Figure 1 As shown, the first lower channel 301 and the second lower channel 302 are alternately connected in sequence to form an electrolyte input channel 3, and the electrolyte in the electrolyte input channel 3 flows into each electrolysis chamber 1 through the second flow guide channel 8; the first upper channel 401 and the second upper channel 402 are alternately connected in sequence to form a gas-liquid output channel 4, and the reactants after electrolysis in each electrolysis chamber 1 flow out from the first flow guide channel 7 to the gas-liquid output channel 4.

[0058] See also Figure 4 and Figure 5 A second wavy guide surface 501 is provided on the inner side of the first end plate 5, which is connected to the dual-function electrode 101 through a conductive column, and an input port 3011 is provided on the first end plate 5 along the thickness direction. A third wavy guide surface 601 is provided on the inner side of the second end plate 6, which is connected to the oxygen carrier electrode 103 through a conductive column, and an output port 4021 is provided on the second end plate 6 along the thickness direction; a first guide channel 7 communicating with the output port 4021 is provided on the upper part of the third wavy guide surface 601, and a second guide channel 8 communicating with the electrolyte input channel 3 is provided on the lower part of the third wavy guide surface 601.

[0059] The inlet end of the electrolyte input channel 3 is connected to the input port 3011 for transporting electrolyte into the electrolytic cell. The outlet end of the gas-liquid output channel 4 is connected to the output port 4021 for outputting hydrogen or oxygen products and electrolyte after electrolysis.

[0060] The first end plate 5 and the second end plate 6 are also provided with power terminals and bolt holes. As a specific implementation, nuts 9 and bolts 10 can be used to fix the first end plate 5 and the second end plate 6 together, and then the gaskets 104 and the bipolar plates 2 are pressed tightly to fix the electrolytic chambers.

[0061] The first flow guide channel 7 and the second flow guide channel 8 are located on the side of the bipolar plate 2 and the second end plate 6 close to the oxygen carrier electrode 103 , and the depth of the first flow guide channel 7 and the second flow guide channel 8 is not greater than half of the thickness of the bipolar plate 2 .

[0062] The material of the dual-function electrode 101 of this embodiment includes one of metal phosphide, metal sulfide, metal carbide, metal nitride, and metal oxide. Specifically, the dual-function electrode 101 is CoFeNiPOx in-situ electrodeposited on nickel foam.

[0063] The size of the dual-function electrode 101 in this embodiment is not larger than the size of the oxygen carrier electrode 103. Specifically, the size of the dual-function electrode 101 is one third of the size of the oxygen carrier electrode 103.

[0064] The porous separator 102 of this embodiment is made of an insulating porous material, and is used to prevent short circuit between the bifunctional electrode 101 and the oxygen carrier electrode 103. Specifically, the porous separator 102 is a glass fiber separator.

[0065] The oxygen carrier electrode 103 of this embodiment uses nickel hydroxide as an active component, specifically nickel foam loaded Ni 0.9 Co 0.1 (OH) 2 .

[0066] As a preferred embodiment, the bifunctional electrode 101 and the oxygen carrier electrode 103 are circular in cross section, the bipolar plate 2 is circular in cross section, and the porous separator 102 is one of a ring, a full-size circle and a hollow circle.

[0067] Example 2

[0068] This embodiment provides a method for operating the membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle described in Embodiment 1, including step-by-step production of hydrogen and oxygen.

[0069] The step-by-step production of hydrogen and oxygen specifically includes:

[0070] By controlling the external power switch to switch the operating conditions of the electrolyzer, at least one electrolyzer is operated alternately in the first operating condition and the second operating condition in sequence, so as to realize the step-by-step production of hydrogen and oxygen in the same space;

[0071] The first working condition is: in a 5M KOH electrolyte at 25°C, the first end plate 5 and the second end plate 6 are connected to the negative electrode and the positive electrode of the external power supply respectively, after power is turned on, the bifunctional electrode 101 promotes the electrolysis of water to produce hydrogen, the active components in the oxygen carrier electrode 103 are oxidized to oxidized oxygen carriers, and hydrogen is output from the gas-liquid output channel 4;

[0072] The second working condition is: in a 5M KOH electrolyte at 90°C, the polarity of the external power supply is reversed, that is, the first end plate 5 and the second end plate 6 are respectively connected to the positive and negative electrodes of the external power supply. After power is turned on, the bifunctional electrode 101 promotes the electrolysis of water to produce oxygen, and the oxidized oxygen carrier in the oxygen carrier electrode 103 is partially spontaneously reduced under the action of the temperature field and is completely reduced under the action of the electric field, and oxygen is output from the gas-liquid output channel 4.

[0073] Comparative Example

[0074] This comparative example provides an operation method of the membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle described in Example 1, which is different from Example 2 in that the electrolyte temperature is 25°C, that is, the electrolysis process only relies on electric field energy supply.

[0075] At 100mA cm - 2, the single electrolysis chambers of the comparative example and Example 2 were tested, and the cell voltage data obtained were as follows: Figure 6 As shown in (a) and (b).

[0076] Compared with the comparative example that relies only on electric field energy supply, the combined effect of temperature field and electric field in Example 2 significantly reduces the oxygen production voltage. At the same time, due to the spontaneous reduction of the oxygen carrier under the action of the temperature field, the regeneration rate of the oxygen carrier is accelerated, and the hydrogen production efficiency is significantly higher than that under the condition of only electric field energy supply. Therefore, the coupled energy supply of temperature field and electric field significantly improves the efficiency of hydrogen production cycle.

[0077] Example 3

[0078] This embodiment provides a method for operating the membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle described in Embodiment 1, including continuous production of hydrogen and oxygen.

[0079] The continuous production of hydrogen and oxygen comprises:

[0080] forming a first group of electrolytic cells using at least one electrolytic cell and forming a second group of electrolytic cells using at least one electrolytic cell;

[0081] By controlling the external power switch to switch the operating conditions of the electrolyzers, the first group of electrolyzers operates alternately under the first condition and the second condition. At the same time, the second group of electrolyzers operates alternately under the second condition and the first condition, thereby realizing continuous production of hydrogen and oxygen in different spaces.

[0082] Those skilled in the art can understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle, characterized in that: The electrolytic cell comprises a first end plate (5) and a second end plate (6) respectively connected to an external power source, wherein the first end plate (5) and the second end plate (6) are connected to form a whole, wherein at least one bipolar plate (2) is arranged inside, and electrolytic chambers (1) are respectively formed between the two end plates and the bipolar plates (2), and between two adjacent bipolar plates (2); Each of the electrolysis chambers (1) is provided with a functional component, the functional component comprising a bifunctional electrode (101), a porous partition (102) and an oxygen carrier electrode (103) which are bonded in sequence, the bifunctional electrode (101) being used for catalytic hydrogen evolution under a first operating condition and for catalytic oxygen evolution under a second operating condition; the polarities of the external power supply under the first operating condition and the second operating condition are opposite; A gasket (104) is sleeved on the outer side of the functional component; Except for the gasket (104) sleeved on the outer side of the functional component in the electrolysis chamber (1) close to the first end plate (5), which is not provided with the first upper channel (401), the upper parts of the remaining gaskets (104) are all provided with the first upper channel (401) along the thickness direction; A first lower channel (301) is provided at the lower part of all gaskets (104); First flow channel areas (201) are provided on both sides of the bipolar plate (2), and the first flow channel areas (201) on both sides are electrically connected to the oxygen carrier electrode (103) and the bifunctional electrode (101) respectively through conductive columns distributed thereon, so that the multiple electrolysis chambers (1) are sequentially connected in series; The upper part of the bipolar plate (2) is provided with a second upper channel (402) along the thickness direction, and the lower part is provided with a second lower channel (302) along the thickness direction; the upper part of the first flow channel area (201) is provided with a first flow guide channel (7) communicating with the second upper channel (402); and the lower part of the first flow channel area (201) is provided with a second flow guide channel (8) communicating with the second lower channel (302); The first lower channel (301) and the second lower channel (302) are alternately connected in sequence to form an electrolyte input channel (3), and the electrolyte in the electrolyte input channel (3) flows into each electrolytic chamber (1) through the second flow guide channel (8); The first upper channel (401) and the second upper channel (402) are alternately connected in sequence to form a gas-liquid output channel (4), and the electrolysis products and electrolyte in each electrolysis chamber (1) flow out from the first flow guide channel (7) to the gas-liquid output channel (4); A second flow channel area (501) is provided inside the first end plate (5), which is connected to the dual-function electrode (101) via a conductive column, and an input port (3011) is provided on the first end plate (5) along the thickness direction; A third flow channel region (601) is provided inside the second end plate (6), which is connected to the oxygen carrier electrode (103) via a conductive column, and an output port (4021) is provided on the second end plate (6) along the thickness direction; The upper portion of the third flow channel region (601) is provided with a first flow guide channel (7) communicating with the output port (4021), and the lower portion of the third flow channel region (601) is provided with a second flow guide channel (8) communicating with the electrolyte input channel (3); The inlet end of the electrolyte input channel (3) is connected to the input port (3011), and the outlet end of the gas-liquid output channel (4) is connected to the output port (4021).

2. The membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle according to claim 1 is characterized in that: The first flow guide channel (7) and the second flow guide channel (8) are located on the side of the bipolar plate (2) and the second end plate (6) close to the oxygen carrier electrode (103).

3. The membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle according to claim 2 is characterized in that: The depth of the first flow guide channel (7) and the second flow guide channel (8) is no greater than half the thickness of the bipolar plate (2).

4. The membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle according to claim 1 is characterized in that: The material of the bifunctional electrode (101) includes one of metal phosphide, metal sulfide, metal carbide, metal nitride and metal oxide.

5. The membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle according to claim 1 is characterized in that: The size of the bifunctional electrode (101) is no larger than the size of the oxygen carrier electrode (103).

6. The membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle according to claim 1 is characterized in that: The oxygen carrier electrode (103) is an electrode with nickel hydroxide as a main component.

7. The membraneless water electrolysis hydrogen production electrolyzer based on chemical chain cycle according to claim 1 is characterized in that: The porous partition (102) is a hollow or non-hollow sheet structure, and is made of an insulating porous material.

8. A method for operating a membraneless water electrolysis hydrogen production electrolyzer based on chemical chaining cycle as claimed in any one of claims 1 to 7, characterized in that: The method comprises the step-by-step production of hydrogen and oxygen, which comprises: By controlling the external power switch to switch the operating conditions of the electrolyzer, at least one of the electrolyzers is operated alternately in the first operating condition and the second operating condition in sequence, so as to realize the step-by-step production of hydrogen and oxygen in the same space; The first working condition is: in an electrolyte at 20-50° C., the first end plate (5) and the second end plate (6) are connected to the negative electrode and the positive electrode of an external power supply respectively, and after power is turned on, the bifunctional electrode (101) promotes the electrolysis of water to produce hydrogen, the active components in the oxygen carrier electrode (103) are oxidized to oxidized oxygen carriers, and hydrogen is output from the gas-liquid output channel (4); The second working condition is: in an electrolyte at 50-100° C., the polarity of the external power supply is reversed, that is, the first end plate (5) and the second end plate (6) are connected to the positive electrode and the negative electrode of the external power supply respectively, and after power is turned on, the bifunctional electrode (101) promotes the electrolysis of water to produce oxygen, and the oxidized oxygen carrier in the oxygen carrier electrode (103) is partially spontaneously reduced under the action of the temperature field and is completely reduced under the action of the electric field, and oxygen is output from the gas-liquid output channel (4).

9. The operating method according to claim 8, characterized in that: The operation method also includes continuous production of hydrogen and oxygen, which includes: Using at least one of the electrolytic cells to form a first group of electrolytic cells, and using at least one of the electrolytic cells to form a second group of electrolytic cells; By controlling the external power switch to switch the operating conditions of the electrolytic cells, the first group of electrolytic cells operates alternately under the first operating condition and the second operating condition, and at the same time, the second group of electrolytic cells operates alternately under the second operating condition and the first operating condition, thereby realizing continuous production of hydrogen and oxygen in different spaces.

10. The operating method according to claim 8, characterized in that: The electrolyte is KOH or NaOH solution.

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