Device and method for preparing electrode material in situ

Abstract

The invention discloses a device for in-situ preparation of an electrode material and a preparation method. The device comprises a reaction kettle, a bracket and a bracket rotating module, the bracket rotating module comprises a rotatable base and a rotating motor; the rotating motor is arranged outside the reaction kettle, the rotatable base is arranged inside the reaction kettle, and the bracket is mounted on the rotatable base; the rotatable base is used for controlling the support to rotate around the center axis of the support. The support is provided with multiple layers of bearing structures, and each bearing structure comprises at least one of a hollowed-out net structure, a supporting plate structure and an edge frame structure. The bracket is arranged in the reaction kettle and is used for bearing a plurality of electrode substrates, so that the adjacent electrode substrates are separated, and the electrode materials are prepared in situ in batches. According to the technical scheme provided by the embodiment of the invention, the large-area in-situ loaded electrode material can be grown in batches, and the growth uniformity of the electrode material is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of hydrogen production by electrolysis of water, and in particular to a device and method for in-situ preparation of electrode materials. Background Art

[0002] Hydrogen production by electrolysis of water using renewable electricity is an important way to obtain green hydrogen. In the process of water electrolysis, the overpotential on the electrodes for the anode oxygen evolution reaction (OER) and the cathode hydrogen evolution reaction (HER) becomes the main factor affecting the energy efficiency of water electrolysis.

[0003] The prior art provides that the overpotential of HER reaction or OER reaction can be reduced by adding precious metal catalysts such as platinum, palladium, ruthenium, iridium, etc. to the electrode material, thereby improving the energy efficiency of water electrolysis. However, precious metal catalysts are expensive and scarce in resources, so they are not suitable for large-scale use. In industry, the prior art also provides the use of nickel mesh, nickel foam, and Raney nickel as hydrogen and oxygen evolution electrode materials required for hydrogen production by alkaline water electrolysis. For the HER reaction, the HER activity of nickel metal can be increased by adding elements such as zinc, cobalt, copper, or molybdenum to reduce the overpotential of the HER reaction.

[0004] When preparing a nickel electrode modified with a nickel-molybdenum alloy as a hydrogen evolution cathode, the prior art is to prepare a nickel-molybdenum alloy powder and coat or plasma spray the nickel-molybdenum alloy powder on a metal nickel substrate. However, the coating or plasma spraying method requires a binder or expensive plasma equipment, and has the disadvantages of insufficient bonding strength, high equipment requirements, high energy consumption, and high powder waste rate.

[0005] To this end, the prior art proposes to grow nickel molybdate in situ on a nickel substrate, and then reduce or nitride it to convert it into a nickel electrode loaded with a nickel-molybdenum alloy, which can avoid the above-mentioned shortcomings. At present, researchers have proposed to load nickel molybdate on a nickel substrate by performing a high-temperature and high-pressure hydrothermal reaction in a polytetrafluoroethylene reactor. However, most of the existing studies load nickel molybdate on a nickel substrate with a smaller area, and the number of electrodes that can be obtained in one reaction is small, resulting in the application value of the electrode modified with a nickel-molybdenum alloy for hydrogen evolution cathode in industrialization being limited. Summary of the invention

[0006] The present invention provides a device and a method for in-situ preparation of electrode materials, so as to realize batch growth of electrodes with large-area in-situ loading of electrode materials and improve the growth uniformity of electrode materials.

[0007] According to one aspect of the present invention, there is provided a device for in-situ preparation of electrode materials, comprising: a reaction kettle, a support, and a support rotation module;

[0008] The support rotation module includes a rotatable base and a rotating motor; the rotating motor is arranged outside the reactor, the rotatable base is arranged inside the reactor, and the support is installed on the rotatable base; the rotatable base is used to control the support to rotate around its own central axis;

[0009] The support has a multi-layer bearing structure, which includes at least one of a hollow mesh structure, a support plate structure and an edge frame structure; the support is arranged inside the reactor to support multiple electrode substrates, so that adjacent electrode substrates are separated to prepare electrode materials in situ in batches.

[0010] Optionally, the device for in-situ preparation of electrode materials further comprises: a stirrer; the stirrer comprises a stirring paddle and a stirring motor;

[0011] The stirring motor is arranged outside the reactor and is electrically connected to the stirring paddle; the stirring paddle is used to stir the liquid inside the reactor;

[0012] Alternatively, the stirring paddle is connected to the bracket; the stirring paddle is used to drive the bracket to rotate.

[0013] Optionally, the device for in-situ preparation of electrode materials further comprises: a liquid inlet module and a liquid discharge module;

[0014] The liquid inlet module includes a liquid inlet storage tank and a liquid inlet pump; the liquid inlet storage tank is connected to the liquid inlet end of the reactor through the liquid inlet pump, and the liquid inlet pump is used to control the liquid inlet storage tank to inject solution into the reactor;

[0015] The drainage module includes a drainage storage tank and a drainage pump; the drainage storage tank is connected to the liquid outlet end of the reactor through the drainage pump, and the drainage pump is used to control the solution inside the reactor to be discharged to the drainage storage tank.

[0016] Optionally, the device for in-situ preparation of electrode materials further includes: a controller;

[0017] The controller is electrically connected to the liquid inlet pump, the liquid discharge pump, the stirring motor and the rotating motor respectively; the controller is used to control the liquid inlet pump, the liquid discharge pump, the stirring motor and the rotating motor to start or stop.

[0018] According to another aspect of the present invention, there is provided a method for preparing an electrode material in situ, characterized in that the method is performed using the device for preparing an electrode material in situ as described in any embodiment of the first aspect;

[0019] The method for preparing the electrode material in situ comprises:

[0020] Placing a plurality of nickel meshes in layers on a support, and installing the support on a rotatable base in a reaction kettle;

[0021] Injecting a reaction solution into the reactor until a preset liquid level is reached; wherein the reaction solution is a mixed aqueous solution of molybdate and nickel salt;

[0022] The reactor is heated to a temperature within a reaction temperature range, and a hydrothermal reaction is performed until a preset reaction time is reached, so as to realize in-situ preparation of electrode materials on the nickel mesh.

[0023] Optionally, when the reaction kettle is heated to a temperature within a reaction temperature range for hydrothermal reaction, the process includes:

[0024] controlling the stirrer to stir the reaction solution;

[0025] Alternatively, the stirrer is controlled to drive the bracket to rotate.

[0026] Optionally, when the reaction kettle is heated to a temperature within a reaction temperature range for hydrothermal reaction, the method further comprises:

[0027] The rotatable base is controlled to drive the bracket to rotate around its own central axis in a preset rotation direction; wherein the preset rotation direction includes clockwise and / or counterclockwise.

[0028] Optionally, after injecting the reaction solution into the reactor, the method further comprises:

[0029] Close the lid of the reactor and check the air tightness of the reactor.

[0030] Optionally, the method for checking the air tightness of the reactor comprises:

[0031] High-pressure nitrogen is introduced into the reactor until the pressure reaches a preset pressure, and the preset sealing time is maintained to detect whether the pressure drops; if the pressure does not drop, the airtightness of the reactor is good.

[0032] Optionally, after the hydrothermal reaction is performed until a preset reaction time is reached, the method further comprises:

[0033] After the reactor is restored to normal temperature and pressure, the nickel mesh on which the electrode material is grown in the reactor is taken out, washed with water and dried.

[0034] The device for preparing electrode materials in situ provided by an embodiment of the present invention is provided with a reactor, a bracket and a bracket rotation module. Among them, the reactor is a large reactor with a relatively large size. The bracket rotation module includes a rotatable base and a rotating motor, the rotating motor is arranged outside the reactor, and the rotatable base 31 is arranged inside the reactor, and the rotating motor can control the rotatable base to rotate. The bracket has a multi-layer bearing structure, which can carry multiple electrode substrates, which is conducive to the mass production of electrodes. There is a certain interval between the two adjacent layers of the bearing structure, so that there is also a certain interval between the two adjacent electrode substrates placed on the bracket, and the reaction solution can be fully in contact with the two surfaces of the electrode substrate, which is conducive to the growth of a large-area electrode with good uniformity of in-situ loading of nickel molybdate. During the reaction process, the rotating motor drives the bracket to rotate through the rotatable base, stirs the reaction solution, and evenly disperses the solute in the solvent, further improving the uniformity of the electrode of large-area batch in-situ loading electrode materials.

[0035] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 is a schematic structural diagram of a device for in-situ preparation of electrode materials provided according to an embodiment of the present invention;

[0038] Figure 2 is a schematic structural diagram of another device for in-situ preparation of electrode materials provided according to an embodiment of the present invention;

[0039] Figure 3 is a schematic structural diagram of another device for in-situ preparation of electrode materials provided according to an embodiment of the present invention;

[0040] Figure 4 is a schematic structural diagram of another device for in-situ preparation of electrode materials provided according to an embodiment of the present invention;

[0041] Figure 5 is a schematic flow chart of a method for in-situ preparation of electrode materials according to an embodiment of the present invention;

[0042] Figure 6is a schematic flow chart of another method for in-situ preparing an electrode material according to an embodiment of the present invention;

[0043] Figure 7 It is a schematic flow chart of another method for in-situ preparation of electrode materials provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] An embodiment of the present invention provides a device for in-situ preparation of electrode materials. Figure 1 A schematic diagram of the structure of a device for in-situ preparation of electrode materials provided by an embodiment of the present invention. Figure 1 As shown, the device 100 for in-situ preparation of electrode materials includes: a reaction kettle 10 , a support 20 and a support rotating module 30 .

[0047] The support rotation module 30 includes a rotatable base 31 and a rotating motor 32; the rotating motor 32 is arranged outside the reactor 10, the rotatable base 31 is arranged inside the reactor 10, and the support 20 is installed on the rotatable base 31; the rotatable base 31 is used to control the support 20 to rotate around its own central axis.

[0048] The bracket 20 has a multi-layer bearing structure, which includes at least one of a hollow mesh structure, a support plate structure and an edge frame structure; the bracket 20 is arranged inside the reactor 10 to carry multiple electrode substrates and separate adjacent electrode substrates to prepare electrode materials in situ in batches.

[0049] For example, the reactor 10 is different from the laboratory reactor. A large reactor is used in the embodiment of the present invention, for example, the volume can be 400L, so that an electrode substrate with a larger area can be placed in the reactor 10, and an electrode with a larger area can be grown to achieve industrial application. The reactor 10 can be a heat jacket reactor, that is, a heat exchange pipe 11 is arranged outside the reactor cavity. After the reaction starts, the heat exchange pipe 11 can be used to heat the reactor 10 by external hot oil, steam heat exchange or directly by electric heating. And the reactor 10 is equipped with an interlocking feedback device. When the reactor 10 is heated, if the temperature inside the reactor 10 exceeds the set value or the pressure exceeds the set value, the interlocking feedback device can automatically disconnect the heating switch of the reactor 10 to ensure the safety of the use of the reactor 10.

[0050] The bracket 20 is a multi-layer structure, and a plurality of support columns are arranged around the edge of the bearing structure. The multi-layer bearing structure is arranged in parallel along the extension direction of the support column, and the edge is fixed to the support column, so that there is a certain interval between the two adjacent layers of the bearing structure in the multi-layer bearing structure. The number of layers of the bracket 20 is limited by the cavity height of the reactor 10. For example, the number of layers of the bracket 20 can be 10 to 30 layers, which is not limited here. As the number of layers of the bracket 20 increases, the number of electrodes prepared in a single time also increases. For example, in order to improve the stability of the bearing structure, the number of support columns can be set to 3, which is not limited here. For example, in the embodiment of the present invention, the electrode substrate is a nickel mesh, and nickel molybdate is in situ loaded on the surface of the nickel mesh as an electrode material. Each layer of the bearing structure of the bracket 20 is used to carry the nickel mesh, so that there is a certain interval between two adjacent nickel meshes. For example, the interval can be 2 to 5 cm, which is not limited here. In this way, a certain interval is set between two adjacent nickel meshes, so that the reaction solution is in full contact with both surfaces of each nickel mesh, and the nickel molybdate is loaded in situ on each surface without affecting each other, which is conducive to the growth of an electrode with uniform in-situ nickel molybdate loading on the entire surface. The form of each layer of the supporting structure of the bracket 20 can be a hollow mesh structure, a support plate structure, or an edge frame structure, which is not limited here. Among them, the shape of the nickel mesh can be circular or quadrilateral, so the edge shape of each layer of the supporting structure in the bracket 20 can also be circular or quadrilateral.

[0051] The size of the bracket 20 is determined by the size of the inner cavity of the reactor 10. Since the bracket 20 can be installed inside the reactor 10 or taken out from the reactor 10, the size of the bracket 20 needs to be slightly smaller than the size of the inner cavity of the reactor 10. Multiple positions for carrying nickel meshes can be formed by setting a slot in each layer of the supporting structure of the bracket 20, so that multiple nickel meshes can be carried on one layer of the bracket 20 to increase the number of electrodes obtained by one reaction. However, since the size of the bracket 20 is limited by the reactor 10, if multiple nickel meshes are placed on one layer of the supporting structure of the bracket 20, the size of the nickel mesh needs to be reduced. Preferably, a nickel mesh is placed on each layer of the supporting structure of the bracket 20, and the nickel meshes placed on each layer of the supporting structure have the same spacing and are placed in a concentric manner, so that the stability of the nickel mesh during the reaction process can be guaranteed, and a large area of ​​in-situ nickel molybdate loaded electrodes can be obtained in batches. Before placing the nickel mesh on the bracket 20, it needs to be cut and trimmed according to the size of the electrolytic cell, and the size of the nickel mesh is also limited by the size of the reactor 10 and the bracket 20. After cutting, a nickel mesh having the same size and shape as the bracket can be obtained. For example, the size of the nickel mesh can generally be 0.5 to 2 m, which is not limited here.

[0052] The rotatable base 31 is arranged at the bottom of the cavity inside the reactor 10, and the bracket 20 can be installed on the rotatable base 31 when placed inside the reactor 10. The rotating motor 32 arranged outside the reactor 10 is electrically connected to the rotatable base 31, and can drive the rotatable base 31 to rotate through the speed gear and the transmission rod. Before the reaction, the nickel mesh is placed on the bracket 20, and the bracket 20 is placed on the rotatable base 31 inside the reactor 10. During the reaction, the rotating motor 32 drives the bracket 20 to rotate through the rotatable base 31, and the reaction solution conducts opposite advection mass transfer on the surface of the nickel mesh, and accelerates the hydrothermal reaction of the reaction solution. Exemplarily, the rotation speed of the rotatable base 31 can be 10 to 100 r / min, which is not limited here.

[0053] The device 100 for preparing electrode materials in situ provided by the embodiment of the present invention is provided with a reactor 10, a support 20 and a support rotation module 30. Among them, the reactor 10 is a large reactor with a relatively large size. The support rotation module 30 includes a rotatable base 31 and a rotating motor 32, the rotating motor 32 is arranged outside the reactor 10, the rotatable base 31 is arranged inside the reactor 10, and the rotating motor 32 can control the rotatable base 31 to rotate. The support 20 has a multi-layer bearing structure, which can carry multiple electrode substrates, which is conducive to the mass production of electrodes. There is a certain interval between the adjacent two layers of the bearing structure, so that there is also a certain interval between the adjacent two electrode substrates placed on the support 20, and the reaction solution can be fully in contact with the two surfaces of the electrode substrate, which is conducive to the growth of a large-area electrode with good uniformity of in-situ loading of nickel molybdate. During the reaction process, the rotating motor 32 drives the support 20 to rotate through the rotatable base 31, stirs the reaction solution, and evenly disperses the solute in the solvent, further improving the uniformity of the electrode of the large-area batch in-situ loading electrode material.

[0054] Optionally, Figure 2 is a schematic structural diagram of another device for in-situ preparation of electrode materials provided by an embodiment of the present invention, Figure 3 FIG. 1 is a schematic diagram of the structure of another device for in-situ preparation of electrode materials provided by an embodiment of the present invention. Figure 2 and Figure 3 The device 100 for in-situ preparation of electrode materials further includes: a stirrer 40 ; the stirrer 40 includes a stirring paddle 41 and a stirring motor 42 .

[0055] The stirring motor 42 is disposed outside the reactor 10 and is electrically connected to the stirring paddle 41; the stirring paddle 41 is used to stir the liquid inside the reactor 10;

[0056] Alternatively, the stirring paddle 41 is connected to the bracket 20; the stirring paddle 41 is used to drive the bracket 20 to rotate.

[0057] An achievable embodiment, for example, see Figure 2 , the stirring paddle 41 is suspended and fixed at the upper part of the cavity of the reactor 10, and the height at which the stirring paddle 41 is fixed is higher than the height of the bracket 20. During the reaction process, the stirring motor 42 can control the stirring paddle 41 to rotate to stir the reaction solution in the reactor 10 evenly, so that during the reaction process, the solute in the reaction solution is evenly dissolved in the solvent, so that the nickel molybdate in situ loaded on the surface of the nickel mesh at different layers of the bracket 20 has good uniformity, and prevents the unit area loading density of the nickel molybdate loaded on the nickel mesh at the lower layer of the bracket 20 from being greater than the unit area loading density of the nickel molybdate loaded on the nickel mesh at the upper layer of the bracket 20 due to uneven stirring of the reaction solution.

[0058] In addition, after the reaction starts, the stirring paddle 41 and the rotatable base 31 can rotate at the same time, that is, the stirring paddle 41 and the nickel mesh carried by the bracket 20 rotate at the same time to enhance heat conduction and solution mass transfer. For example, the rotation direction of the stirring paddle 41 can be controlled to be opposite to the rotation direction of the rotatable base 31, that is, the stirring motor 42 controls the stirring paddle 41 to rotate in a clockwise direction, and the rotating motor 32 controls the rotatable base 31 to rotate in a counterclockwise direction; or, the stirring motor 42 controls the stirring paddle 41 to rotate in a counterclockwise direction, and the rotating motor 32 controls the rotatable base 31 to rotate in a clockwise direction, which is not limited here. In this way, the stirring paddle 41 and the rotatable base 31 are controlled to rotate in opposite directions, so that the reaction solution can be carried out on the surface of the nickel mesh carried by the bracket 20. The mass transfer is carried out in opposite directions, further improving the effect of heat conduction, and the solute in the reaction solution is evenly dispersed in the solvent, which is conducive to improving the uniformity of in-situ preparation of nickel molybdate on the surface of each nickel mesh.

[0059] Another achievable embodiment, for example, see Figure 3 , the stirring paddle 41 is connected to the upper end of the bracket 20. At the beginning of the reaction, the stirring motor 42 controls the stirring paddle 41 to rotate. Since the stirring paddle 41 is connected to the bracket 20, the stirring paddle 41 can drive the bracket 20 to rotate at the same time. The bracket 20 carries multiple nickel meshes. During the rotation process, the flow rate of the reaction solution on the surface of the nickel mesh is accelerated, which promotes the opposite horizontal mass transfer, and can achieve the effect of stirring the reaction solution, thereby also improving the uniformity of the in-situ growth of nickel molybdate on the surface of the nickel mesh.

[0060] Optionally, Figure 4 FIG. 1 is a schematic diagram of the structure of another device for in-situ preparation of electrode materials provided by an embodiment of the present invention. Figure 4 As shown, the device 100 for in-situ preparation of electrode materials further includes: a liquid inlet module 50 and a liquid discharge module 60 .

[0061] The liquid inlet module 50 includes a liquid inlet tank 51 and a liquid inlet pump 52; the liquid inlet tank 51 is connected to the liquid inlet end of the reactor 10 through the liquid inlet pump 52, and the liquid inlet pump 52 is used to control the liquid inlet tank 51 to inject solution into the reactor 10; the liquid discharge module 60 includes a liquid discharge tank 61 and a liquid discharge pump 62; the liquid discharge tank 61 is connected to the liquid outlet end of the reactor 10 through the liquid discharge pump 62, and the liquid discharge pump 62 is used to control the solution inside the reactor 10 to be discharged to the liquid discharge tank 61.

[0062] Exemplarily, the liquid inlet storage tank 51 is connected to the liquid inlet port on the reactor 10 through a liquid inlet pipeline, and a liquid inlet pump 52 is provided on the liquid inlet pipeline. The liquid inlet pump 52 is used to control the connection or disconnection between the liquid inlet storage tank 51 and the reactor 10. After the bracket 20 carrying multiple nickel meshes is installed on the rotatable base 31 inside the reactor 10, the liquid inlet pump 52 controls the connection between the liquid inlet storage tank 51 and the liquid inlet port of the reactor 10, so that the reaction solution in the liquid inlet storage tank 51 is injected into the reactor 10, until the preset liquid level of the reactor 10 is reached, the liquid inlet pump 52 controls the disconnection between the liquid inlet storage tank 51 and the liquid inlet port of the reactor 10, so that the reaction solution stops being injected into the reactor 10.

[0063] Similarly, the drainage tank 61 is connected to the drainage port on the reactor 10 through a drainage pipeline, and a drainage pump 62 is provided on the drainage pipeline. The drainage pump 62 is used to control the connection or disconnection between the drainage tank 61 and the reactor 10. After the preparation is completed, the drainage pump 62 is used to control the connection between the drainage tank 61 and the drainage port of the reactor 10, so that the solution in the reactor 10 is discharged from the drainage port to the drainage tank 61; until the reaction solution in the reactor 10 is completely drained, the drainage pump 62 controls the disconnection between the drainage tank 61 and the drainage port of the reactor 10, so that the reactor 10 no longer discharges liquid.

[0064] Optionally, based on the above embodiments, continue to refer to Figure 4 The device 100 for in-situ preparation of electrode materials also includes: a controller 70.

[0065] The controller 70 is electrically connected to the liquid inlet pump 52 , the liquid discharge pump 62 , the stirring motor 42 and the rotating motor 32 ; the controller 70 is used to control the liquid inlet pump 52 , the liquid discharge pump 62 , the stirring motor 42 and the rotating motor 32 to start or stop.

[0066] Exemplarily, the controller 70 can be electrically connected to the inlet pump 52, the discharge pump 62, the stirring motor 42 and the rotating motor 32 respectively by wired connection, so as to realize that before the reaction starts, the inlet pump 52 is controlled to start, so that the inlet storage tank 51 injects the reaction solution into the reactor 10, until the solution in the reactor 10 reaches the preset liquid level, the inlet pump 52 is controlled to be turned off; at the beginning of the reaction, the stirring motor 42 and the rotating motor 32 are controlled to start, so that the stirring paddle 41 and the rotatable base 31 rotate; after the reaction is completed, the discharge pump 62 is controlled to start, so that the reaction solution in the reactor 10 is discharged to the discharge storage tank 61, until the solution in the reactor 10 is completely discharged, and the discharge pump 62 is controlled to be turned off. Exemplarily, a liquid level sensor is provided at the position of the preset liquid level on the inner wall of the cavity of the reactor 10, and the liquid level sensor and the controller 70 can be connected by wireless connection. When the liquid level sensor detects that the liquid level of the reaction solution injected into the reactor 10 reaches a preset liquid level, a signal is sent to the controller 70, and the controller 70 controls the liquid inlet pump 52 to turn off and stop the liquid inlet.

[0067] The embodiment of the present invention also provides a method for preparing an electrode material in situ. Figure 5 1 is a schematic flow chart of a method for preparing an electrode material in situ according to an embodiment of the present invention. The method for preparing an electrode material in situ can be performed by using the device for preparing an electrode material in situ according to any of the above embodiments. Figure 5 As shown, the method for preparing the electrode material in situ specifically comprises the following steps:

[0068] S110, placing a plurality of nickel meshes in layers on a bracket, and installing the bracket on a rotatable base in the reaction kettle.

[0069] Among them, the bracket and the inner wall of the reactor are made of titanium alloy, polytetrafluoroethylene or stainless steel, which is conducive to reducing corrosion and reducing the growth of nickel molybdate on the surface other than the nickel mesh. The bracket includes a multi-layer bearing structure, which is used to carry the nickel mesh and allow a certain interval between the two adjacent layers of nickel mesh. The nickel mesh used is a clean nickel mesh after degreasing and pickling, and is a large-area nickel mesh after cutting and trimming, and its size is the same as the size of each layer of the bearing structure in the bracket. Multiple nickel meshes are placed on each layer of the bearing structure of the bracket, and the bracket is fixed on a rotatable base.

[0070] S120, injecting a reaction solution into the reactor until a preset liquid level is reached; wherein the reaction solution is a mixed aqueous solution of molybdate and nickel salt.

[0071] Among them, the preset liquid level height can be set by the user according to actual needs, and is not limited here. For example, for a nickel mesh as an electrode substrate, the electrode material prepared in situ on the nickel mesh is nickel molybdate, and the reaction solution used can be a mixed aqueous solution of molybdate and nickel salt. The controller controls the start of the liquid inlet pump on the liquid inlet pipeline so that the reaction solution in the liquid inlet storage tank is injected into the reactor from the liquid inlet port of the reactor. The liquid level in the reactor continues to rise until the liquid level reaches the preset liquid level height, and the controller controls the liquid inlet pump to shut off, thereby stopping the injection of solution into the reactor.

[0072] S130, heating the reactor to a temperature within a reaction temperature range, and performing a hydrothermal reaction until a preset reaction time is reached, so as to realize in-situ preparation of electrode materials on the nickel mesh.

[0073] Among them, the reaction temperature range is the temperature for the hydrothermal reaction in the reactor, that is, the temperature that needs to be reached and maintained for heating the reactor; the preset reaction time is the duration of the hydrothermal reaction. The reaction temperature range and the preset reaction time can be set by the user according to actual needs, and are not limited here. Exemplarily, the reaction temperature range can be 120 to 160 ° C, and the preset reaction time can be 3 to 12 hours. After starting the reaction, the reactor is heated until the reactor temperature reaches the reaction temperature range, and then the hydrothermal reaction is continued for the preset reaction time to complete the in-situ preparation of nickel molybdate electrode materials on the surface of the nickel mesh in batches.

[0074] The preparation method of the in-situ prepared electrode material provided by the embodiment of the present invention is through placing a plurality of large-area nickel meshes on different layers of a bracket, and placing the bracket in a reactor. The use of such a structure of the bracket to carry the nickel mesh can make a certain interval between two adjacent layers of nickel mesh, and the reaction solution can be in full contact with the two surfaces of each nickel mesh, thereby improving the uniformity of the in-situ prepared electrode material on the surface of the nickel mesh. After the reaction solution is injected into the reactor until the liquid level reaches a preset liquid level, the reactor is heated so that the temperature of the reactor reaches the reaction temperature range, and a hydrothermal reaction is carried out. When the duration of the hydrothermal reaction reaches the preset reaction time, the hydrothermal reaction is completed. The preparation method can realize the large-area electrode of the in-situ prepared electrode material through a single reaction batch.

[0075] Exemplarily, based on the above embodiment, in step S130, when the reaction kettle is heated to a temperature within the reaction temperature range for hydrothermal reaction, the following steps are performed:

[0076] controlling the stirrer to stir the reaction solution;

[0077] Alternatively, the stirrer is controlled to drive the support to rotate.

[0078] Wherein, the agitator includes a stirring paddle and a stirring motor, the stirring paddle is arranged inside the reactor, and the stirring motor is arranged outside the reactor. Exemplarily, the stirring paddle can be suspended and extended below the liquid level of the reaction solution in the reactor. At the beginning of the reaction, the controller controls the stirring motor to start, and the stirring motor controls the stirring paddle to rotate, so as to fully stir the reaction solution, so that the solute in the reaction solution is evenly dispersed in the solvent, and the solute content of the reaction solution at the bottom of the reactor is prevented from being higher than the solute content of the reaction solution at the top of the reactor, so that the uniformity of the electrode material quality loaded on the surface of the electrode prepared in batches is better. Exemplarily, the stirring rate of the stirring paddle can be 100 to 300r / min. Alternatively, the stirring paddle can also be extended into the reactor and connected to the bracket. At the beginning of the reaction, while the stirring motor controls the rotation of the stirring paddle, the stirring paddle can also drive the bracket to rotate at the same time, which can also achieve the effect of stirring the reaction solution, thereby promoting the reaction solution to carry out opposite advection mass transfer on the surface of the nickel mesh, and improving the uniformity of the in-situ growth of nickel molybdate on the surface of the nickel mesh of the reaction solution. Exemplarily, based on the above embodiment, in step S130, when the reaction kettle is heated to a temperature within the reaction temperature range for performing a hydrothermal reaction, the method further includes:

[0079] The rotatable base is controlled to drive the bracket to rotate around its own central axis in a preset rotation direction; wherein the preset rotation direction includes clockwise and / or counterclockwise.

[0080] Specifically, at the beginning of the reaction, the controller can also control the rotation motor to start, so that the rotation motor controls the rotation of the rotatable base, and the rotatable base drives the bracket to rotate along the preset rotation direction to fully stir the reaction solution, so that sufficient heat exchange and mass transfer are accelerated, and the uniformity of the in-situ loading of nickel molybdate on the surface of the nickel mesh is improved. Among them, the preset rotation direction of the rotatable base can be clockwise, counterclockwise, or can be switched between clockwise and counterclockwise, so as to fully stir the solution.

[0081] Based on the above embodiments, when the hydrothermal reaction is carried out, only the stirring paddle can be controlled to rotate to stir the reaction solution; only the rotatable base can be controlled to rotate to fully exchange heat and accelerate mass transfer; or, the stirring paddle and the rotatable base can be controlled to rotate at the same time to fully stir the reaction solution and improve the uniformity of in-situ preparation of nickel molybdate on the surface of the nickel mesh. Preferably, controlling the stirring paddle and the rotatable base to rotate in opposite directions at the same time can effectively improve the uniformity of the solute in the reaction solution dispersed in the solvent.

[0082] Optionally, Figure 6 FIG. 1 is a flow chart of another method for preparing an electrode material in situ provided by an embodiment of the present invention. Figure 6 As shown, the method for preparing the in-situ electrode material comprises:

[0083] S210, placing a plurality of nickel meshes in layers on a bracket, and installing the bracket on a rotatable base in the reactor.

[0084] S220, injecting a reaction solution into the reactor until a preset liquid level is reached; wherein the reaction solution is a mixed aqueous solution of molybdate and nickel salt.

[0085] S230. Close the lid of the reactor and check the air tightness of the reactor.

[0086] Exemplarily, after the bracket is placed in the reactor, the lid of the reactor is sealed tightly. Before the reaction starts, it is necessary to first check whether the air tightness of the reactor is good to prevent the quality of the nickel molybdate prepared in situ from being affected by the poor air tightness of the reactor. Exemplarily, the method for checking the air tightness of the reactor includes: passing high-pressure nitrogen into the reactor until the pressure reaches a preset pressure, maintaining a preset sealing time to detect whether the pressure drops; if the pressure does not drop, the air tightness of the reactor is good. Among them, the preset pressure can be set to 1MPa, and the preset sealing time can be set to 10 minutes. When closing the lid of the reactor for air tightness inspection, high-pressure nitrogen is passed into the reactor until the internal pressure of the reactor is maintained at 1MPa, then the high-pressure nitrogen is stopped and the vent is sealed, and it is left to stand for 10 minutes. After that, the pressure in the reactor is tested again, and the air tightness of the reactor is judged according to the pressure change. If the pressure drops significantly, it indicates that the reactor is leaking; if the pressure does not change significantly, it indicates that the reactor is airtight and can be used for hydrothermal reaction to prepare electrode materials. When it is determined that the reactor is airtight, the high-pressure nitrogen in the reactor is discharged until the pressure reaches normal pressure, and heating is started for hydrothermal reaction.

[0087] S240, heating the reactor to a temperature within a reaction temperature range, and performing a hydrothermal reaction until a preset reaction time is reached, so as to realize in-situ preparation of electrode materials on the nickel mesh.

[0088] Optionally, Figure 7 FIG. 1 is a flow chart of another method for preparing an electrode material in situ provided by an embodiment of the present invention. Figure 7 As shown, the method for preparing the in-situ electrode material comprises:

[0089] S310, placing a plurality of nickel meshes in layers on a bracket, and installing the bracket on a rotatable base in the reactor.

[0090] S320, injecting a reaction solution into the reactor until a preset liquid level is reached; wherein the reaction solution is a mixed aqueous solution of molybdate and nickel salt.

[0091] S330, heating the reactor to a temperature within a reaction temperature range, and performing a hydrothermal reaction until a preset reaction time is reached.

[0092] S340, after the reactor returns to normal temperature and pressure, take out the nickel mesh on which the electrode material is grown in the reactor, wash it with water and dry it, so as to prepare the electrode material in situ on the nickel mesh.

[0093] For example, after the reaction is completed, the temperature in the reactor is restored to room temperature and the pressure is restored to normal pressure, the lid of the reactor is opened, the nickel mesh with in-situ growth of nickel molybdate is taken out, and the nickel mesh is rinsed with deionized water to clean the residual solution on the surface of the nickel mesh immersed in the reaction solution. Then, the cleaned nickel mesh is placed in a blast drying oven, and the nickel mesh is dried at a drying temperature of 110°C and a drying time of 3 hours, and finally a batch-prepared nickel mesh loaded with in-situ nickel molybdate is obtained as an electrode.

[0094] Based on the in-situ preparation methods of electrode materials provided in the above embodiments, a number of specific embodiments and comparative examples are presented below for comparison to determine the effects of different methods for stirring the reaction solution on the in-situ loaded nickel molybdate.

[0095] Example 1

[0096] The method for preparing the electrode material in situ provided in this embodiment mainly comprises the following steps:

[0097] S1. Cut the clean metal nickel mesh after degreasing and pickling to obtain a circular nickel mesh with a diameter of 0.6 meters, place it on a bracket, place 12 layers in total, i.e. 12 circular nickel meshes, and install the bracket on a rotatable base in the reactor; wherein the interval between each layer of nickel mesh is 4.5 centimeters.

[0098] S2. Inject a mixed aqueous solution of 10 g / L ammonium molybdate and 10 g / L nickel chloride in the liquid inlet storage tank into the reactor until the liquid level sensor in the reactor detects that the liquid level has reached 0.8 m, and then the controller controls the liquid inlet pump to shut down.

[0099] S3. Close the lid of the reactor, introduce high-pressure nitrogen until the pressure inside the reactor reaches 1MPa, and check the airtightness of the reactor. If the pressure inside the reactor does not drop after 10 minutes, it indicates that the reactor is airtight, and the high-pressure nitrogen is discharged to normal pressure. Then, start heating the reactor to raise the temperature of the reactor to 140°C; while starting heating, start the stirring motor, control the stirring speed of the stirring paddle to 120r / min, and switch the rotation direction of the stirring paddle every 1 minute.

[0100] S4. The reactor is kept at a constant temperature of 140°C for 6 hours, and then the heating is stopped. When the temperature in the reactor drops to room temperature and the pressure drops to normal pressure, the controller controls the drainage pump to start, so that the reaction solution in the reactor is discharged into the drainage tank. Then the lid of the reactor is opened, the bracket carrying the nickel mesh is taken out, and the bracket and the nickel mesh are cleaned with deionized water.

[0101] S5. Put the nickel mesh loaded with nickel molybdate into a forced air drying oven and dry it at a drying temperature of 110° C. for 3 hours to finally obtain a batch-prepared nickel mesh electrode loaded with nickel molybdate in situ.

[0102] Twelve circular nickel meshes loaded with nickel molybdate were obtained by the preparation method of this embodiment, and five of them were randomly selected. For the five nickel meshes obtained, one small sample with a size of 4 cm × 5 cm was randomly selected from each nickel mesh, for a total of five small samples. For the five small-area nickel meshes loaded with nickel molybdate, after deducting the mass of the nickel mesh of the same area, the unit area loading density of nickel molybdate was 43.5 mg cm -2 、39.6mg cm -2 、40.4mg cm -2 、41.1mg cm -2 and 43.8mgcm -2 , and its relative standard deviation is 4.51%. It can be seen that the in-situ loaded nickel molybdate on the nickel mesh electrode prepared in batches has good consistency and uniformity by stirring the reaction solution with a stirring paddle.

[0103] Example 2

[0104] The main difference between the preparation method of in-situ preparation of electrode materials provided in this embodiment and the preparation method in Example 1 is that this embodiment adopts a method of controlling the rotatable base to drive the bracket to rotate to achieve the effect of stirring the reaction solution; wherein the rotation rate of the rotatable base is 30r / min, and the stirring direction is switched every 3 minutes. Other method steps and parameter values ​​are the same as those in Example 1 and are not described here.

[0105] Twelve circular nickel meshes loaded with nickel molybdate were obtained by the preparation method of this embodiment, and five of them were randomly selected. For the five nickel meshes obtained, one small sample with a size of 4 cm × 5 cm was randomly selected from each nickel mesh, for a total of five small samples. For the five small-area nickel meshes loaded with nickel molybdate, after deducting the mass of the nickel mesh of the same area, the unit area loading density of nickel molybdate was 39.1 mg cm -2 、38.6mg cm -2 、37.8mg cm -2 、37.2mg cm -2and 40.6mgcm -2 , and its relative standard deviation is 3.38%. It can be seen that the rotatable base is used to drive the bracket and the nickel mesh to rotate and stir the reaction solution. The in-situ loaded nickel molybdate on the nickel mesh electrode prepared in batches has good consistency and uniformity, and the effect is better than that of stirring with a stirring paddle.

[0106] Example 3

[0107] The method for in-situ preparing electrode materials provided in this embodiment is different from the preparation method in Example 1 in that this embodiment adopts a method of controlling the stirring paddle to drive the bracket to rotate simultaneously to achieve stirring of the reaction solution; wherein the rotation rate of the stirring paddle to drive the bracket to rotate is 120r / min, and other method steps and parameter values ​​are the same as in Example 1, and are not repeated here.

[0108] Twelve circular nickel meshes loaded with nickel molybdate were obtained by the preparation method of this embodiment, and five of them were randomly selected. For the five nickel meshes obtained, one small sample with a size of 4 cm × 5 cm was randomly selected from each nickel mesh, for a total of five small samples. For the five small-area nickel meshes loaded with nickel molybdate, after deducting the mass of the nickel mesh of the same area, the unit area loading density of nickel molybdate was 39.2 mg cm -2 、38.9mg cm -2 、37.9mg cm -2 、37.4mg cm -2 and 40.8mgcm -2 , and its relative standard deviation is 3.41%. It can be seen that the in-situ loaded nickel molybdate on the batch-prepared nickel mesh electrode has good consistency and uniformity, and the effect is better than that of stirring the reaction solution only by using a stirring paddle to drive the bracket and the nickel mesh to rotate and stir the reaction solution.

[0109] Example 4

[0110] The method for preparing the electrode material in situ provided in this embodiment is different from the method in Example 1 in that the present embodiment adopts a method of controlling the simultaneous rotation of the stirring paddle and the rotatable base to achieve stirring of the reaction solution; wherein the rotation rate of the stirring paddle is 120r / min, the rotation rate of the rotatable base is 30r / min, and the rotation directions of the stirring paddle and the rotatable base are opposite, and the stirring direction is switched every 3 minutes. Other method steps and parameter values ​​are the same as those in Example 1 and are not described in detail here.

[0111] Twelve circular nickel meshes loaded with nickel molybdate were obtained by the preparation method of this embodiment, and five of them were randomly selected. For the five nickel meshes obtained, one small sample with a size of 4 cm × 5 cm was randomly selected from each nickel mesh, for a total of five small samples. For the five small-area nickel meshes loaded with nickel molybdate, after deducting the mass of the nickel mesh of the same area, the unit area loading density of nickel molybdate was 41.6 mg cm -2 、43.2mg cm -2 、42.9mg cm -2 、42.1mg cm -2 and 40.7mgcm -2 , and its relative standard deviation is 2.39%. It can be seen that by controlling the stirring paddle and the rotatable base to rotate simultaneously to stir the reaction solution, the in-situ loaded nickel molybdate on the nickel mesh electrode prepared in batches has good consistency and uniformity, and the effect is better than that of stirring with only a stirring paddle or only a rotatable base.

[0112] Example 5

[0113] This example provides a comparative example of Example 1. Compared with the preparation method in Example 1, the main difference is that this example does not use a bracket, that is, the 12 nickel meshes are not placed on the bracket in layers to leave a certain interval between two adjacent nickel meshes, but the 12 nickel meshes are directly stacked in the reactor. Other method steps and parameter values ​​are the same as those in Example 1 and are not described here.

[0114] Twelve circular nickel meshes loaded with nickel molybdate were obtained by the preparation method of this example, and five of them were randomly selected. Five small-area nickel meshes loaded with nickel molybdate were obtained by the same method as in Example 1. After measurement, the unit area loading density of nickel molybdate was 27.7 mg cm -2 、19.6mg cm -2 , 42.2 mg cm -2 、17.7mg cm -2 and 20.4 mg cm -2 , and its relative standard deviation is as high as 39%. It can be seen that without using a bracket, the uniformity of the nickel molybdate in situ loaded on the surface of the nickel mesh prepared in batches is poor and does not meet the quality requirements of batch production.

[0115] Example 6

[0116] This embodiment provides another comparative example of embodiment 1, which is different from the preparation method in embodiment 1 in that the rotatable base and the stirring paddle are not controlled to rotate to stir the reaction solution. Other method steps and parameter values ​​are the same as those in embodiment 1 and are not described here.

[0117] Twelve circular nickel meshes loaded with nickel molybdate were obtained by the preparation method of this example, and five of them were randomly selected. Five small-area nickel meshes loaded with nickel molybdate were obtained by the same method as in Example 1. The unit area loading densities of nickel molybdate were 36.5 mg cm -2 、39.4mg cm -2 、35.8mg cm -2 、37.9mg cm -2 and 41.6 mg cm -2 , and its relative standard deviation is 6.1%. It can be seen that the uniformity of the in-situ loaded nickel molybdate prepared in this embodiment is inferior to the uniformity of the nickel molybdate prepared in Examples 1 to 3. Therefore, by controlling the rotation of the rotatable base and the stirring paddle to stir the reaction solution, the uniformity of the in-situ loaded nickel molybdate can be effectively improved.

[0118] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for in-situ preparation of electrode materials, characterized in that: include: Reactor, support and support rotation module; The support rotation module includes a rotatable base and a rotating motor; the rotating motor is arranged outside the reactor, the rotatable base is arranged inside the reactor, and the support is installed on the rotatable base; the rotatable base is used to control the support to rotate around its own central axis; The support has a multi-layer bearing structure, which includes at least one of a hollow mesh structure, a support plate structure and an edge frame structure; the support is arranged inside the reactor to support multiple electrode substrates, so that adjacent electrode substrates are separated to prepare electrode materials in situ in batches.

2. The device for in-situ preparation of electrode materials according to claim 1, characterized in that: Also includes: Agitator; the agitator comprises a stirring paddle and a stirring motor; The stirring motor is arranged outside the reactor and is electrically connected to the stirring paddle; The stirring paddle is used to stir the liquid inside the reactor; Alternatively, the stirring paddle is connected to the bracket; the stirring paddle is used to drive the bracket to rotate.

3. The device for in-situ preparation of electrode materials according to claim 2, characterized in that: Also includes: Liquid inlet module and liquid discharge module; The liquid inlet module includes a liquid inlet storage tank and a liquid inlet pump; the liquid inlet storage tank is connected to the liquid inlet end of the reactor through the liquid inlet pump, and the liquid inlet pump is used to control the liquid inlet storage tank to inject solution into the reactor; The drainage module includes a drainage storage tank and a drainage pump; the drainage storage tank is connected to the liquid outlet end of the reactor through the drainage pump, and the drainage pump is used to control the solution inside the reactor to be discharged to the drainage storage tank.

4. The device for in-situ preparation of electrode materials according to claim 3, characterized in that: Also includes: Controller; The controller is electrically connected to the liquid inlet pump, the liquid discharge pump, the stirring motor and the rotating motor respectively; The controller is used to control the start or stop of the liquid inlet pump, the liquid discharge pump, the stirring motor and the rotating motor.

5. A method for preparing an electrode material in situ, characterized in that: The method is performed by using the device for in-situ preparation of electrode materials as described in any one of claims 1 to 4; The method for preparing the electrode material in situ comprises: Placing a plurality of nickel meshes in layers on a support, and installing the support on a rotatable base in a reaction kettle; Injecting a reaction solution into the reactor until a preset liquid level is reached; wherein the reaction solution is a mixed aqueous solution of molybdate and nickel salt; The reactor is heated to a temperature within a reaction temperature range, and a hydrothermal reaction is performed until a preset reaction time is reached, so as to realize in-situ preparation of electrode materials on the nickel mesh.

6. The method for preparing an in-situ electrode material according to claim 5, characterized in that: When the reaction kettle is heated to a temperature within the reaction temperature range for hydrothermal reaction, the method comprises: controlling the stirrer to stir the reaction solution; Alternatively, the stirrer is controlled to drive the bracket to rotate.

7. The method for preparing an in-situ electrode material according to claim 5, characterized in that: When the reaction kettle is heated to a temperature within the reaction temperature range for hydrothermal reaction, the method further comprises: The rotatable base is controlled to drive the bracket to rotate around its own central axis in a preset rotation direction; wherein the preset rotation direction includes clockwise and / or counterclockwise.

8. The method for preparing an in-situ electrode material according to claim 5, characterized in that: After injecting the reaction solution into the reactor, the method further comprises: Close the lid of the reactor and check the air tightness of the reactor.

9. The method for preparing an in-situ electrode material according to claim 8, characterized in that: The method for checking the air tightness of the reactor comprises: High-pressure nitrogen is introduced into the reactor until the pressure reaches a preset pressure, and the preset sealing time is maintained to detect whether the pressure drops; if the pressure does not drop, the airtightness of the reactor is good.

10. The method for preparing an in-situ electrode material according to claim 5, characterized in that: After the hydrothermal reaction is performed until the preset reaction time is reached, the method further comprises: After the reactor is restored to normal temperature and pressure, the nickel mesh on which the electrode material is grown in the reactor is taken out, washed with water and dried.

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