Device and method for measuring wet specific surface area of ​​graphene material

Abstract

The present invention relates to the technical field of detection equipment, and in particular to a device and method for measuring the wet specific surface area of ​​a graphene material. The device comprises an electrolytic tank for storing an electrolyte, wherein two partitions are provided in the electrolytic tank, and the two partitions divide the internal space of the electrolytic tank into a first chamber on the upper side, a second chamber in the middle, and a third chamber on the lower side. The second chamber and the third chamber are respectively provided with a counter electrode and a reference electrode. The wet specific surface area of ​​the graphene material in the production process is measured by adopting a continuous conveying and detection method, so as to adapt to the real-time quality inspection requirements of the continuous production line and ensure that all graphene materials produced in different time periods are sampled. At the same time, the continuous detection method can shorten the single detection cycle. The comparison and measurement of the reference capacitance and the detection capacitance can improve the detection accuracy and avoid the influence of the property change of the electrolyte or the inherent capacitance of the device on the detection result.

Description

Technical Field

[0001] The present invention relates to the technical field of detection equipment, and in particular to a device and method for measuring the wet specific surface area of ​​a graphene material. Background Art

[0002] Graphene, a two-dimensional nanomaterial with an ultra-high specific surface area, excellent conductivity, and chemical stability, has shown great application potential in supercapacitors, lithium-ion batteries, catalytic supports, and sensors. Its wet specific surface area (i.e., the effective surface area in a liquid environment) is one of the key parameters that determine its electrochemical performance, directly affecting its charge storage capacity, the number of reaction active sites, and ion transport efficiency. However, existing measurement technologies face many challenges and are unable to meet the needs of industrial production for efficient, accurate, and in-situ detection.

[0003] The existing measurement methods are mainly BET method or electrochemical method. The BET method relies on the principle of nitrogen adsorption and ensures that the sample is dry. It cannot reflect the actual surface area in a wet state. At the same time, its test cycle is long (>6 hours) and cannot adapt to the real-time quality inspection needs of continuous production lines. The electrochemical method lacks a real-time calibration mechanism for dynamic changes in the electrolyte environment (such as temperature fluctuations and ion concentration gradients), and the graphene dispersion needs to be manually coated on the electrode. Its efficiency is low, and only one sample can be tested at a time, which is difficult to meet the high-throughput testing needs of continuous production in the workshop. Summary of the Invention

[0004] The present invention provides a device and method for measuring the wet specific surface area of ​​a graphene material, which can effectively solve the problems in the background technology.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The device for measuring the wet specific surface area of ​​a graphene material includes an electrolytic tank for storing an electrolyte, wherein two partitions are provided in the electrolytic tank, and the two partitions divide the internal space of the electrolytic tank into a first chamber on the upper side, a second chamber in the middle, and a third chamber on the lower side. The second chamber and the third chamber are respectively provided with a counter electrode and a reference electrode;

[0007] A fixed disk is provided in the first chamber, and a strip of substrate is wound and transported on the fixed disk, and the strip of substrate is wound around the fixed disk at least once;

[0008] The fixed disk is provided with a spraying structure for spraying graphene dispersion onto the surface of the strip-shaped substrate, and a portion of the fixed disk is immersed in the electrolyte in the first chamber.

[0009] In some embodiments of the present invention, the strip-shaped substrate is one of carbon paper, carbon nanofiber, and metal foam with an intermediate interlayer, and the intermediate interlayer is at least one of titanium mesh, stainless steel mesh, and aramid.

[0010] In some embodiments of the present invention, the strip-shaped substrate is composed of a plurality of conductive regions and a plurality of insulating regions that are sequentially and staggeredly connected, and the spraying structure sprays the graphene dispersion onto the conductive regions, or onto the conductive regions and the insulating regions.

[0011] In some embodiments of the present invention, a plurality of conveying rollers are rotatably provided on the outer wall of the fixed disk, a conductive roller is rotatably provided on the bottom of the fixed disk, and the conductive roller is connected to an external power supply. Both ends of the conductive roller are provided with rubber stoppers.

[0012] In some embodiments of the present invention, a buckle cover is provided on the fixed disk, the buckle cover is buckled on a portion of the strip-shaped base on the fixed disk, and the spraying structure is installed on the buckle cover;

[0013] A negative pressure chamber corresponding to the buckle cover is provided in the fixed disk, and a plurality of air holes communicating with the negative pressure chamber are provided on the outer wall of the fixed disk.

[0014] In some embodiments of the present invention, the spraying structure includes an intermediate cylinder and a diffusion channel and a feed channel connected and mounted on the intermediate cylinder, wherein a rotating body is provided in the intermediate cylinder for controlling the connection or disconnection between the diffusion channel and the feed channel;

[0015] The diffusion channel has a flat mouth area connected to the buckle cover, the upper surface of the diffusion channel is a plane area, and the lower surface of the diffusion channel is a concave arc area. The distance between the plane area and the arc area gradually decreases in the direction toward the buckle cover and then gradually increases.

[0016] In some embodiments of the present invention, the diffusion channel and the feed channel are staggered along the axis of the intermediate cylinder, and an air supply channel is provided at one end of the intermediate cylinder close to the feed channel, and a pressure regulating valve is provided on the air supply channel;

[0017] The rotating body synchronously controls the air supply channel to be connected or disconnected with the intermediate cylinder.

[0018] In some embodiments of the present invention, the rotating body is a rotating column having a long groove area, the diffusion channel and the air supply channel are located on the same side of the axis of the intermediate cylinder, and the air supply channel and the feed channel are located on both sides of the axis of the intermediate cylinder. During the rotation of the rotating column, the long groove area is alternately connected to the air supply channel or the feed channel.

[0019] In some embodiments of the present invention, the spraying structure further comprises a power unit for providing power for the rotation of the rotating column;

[0020] The power unit includes a driving disc and a driven disc, the driven disc is in transmission connection with the rotating column, the driving disc includes a coaxial large gear and a small gear, the driven disc includes a coaxial large sector gear disc and a small sector gear disc, and the large sector gear disc and the small sector gear disc are staggered in the circumferential direction, the large gear disc is used in conjunction with the small sector gear disc, and the small gear disc is used in conjunction with the large sector gear disc;

[0021] The driving disc is in driving connection with one of the large sector toothed disc or the small sector toothed disc in the driven disc.

[0022] The method for measuring the wet specific surface area of ​​a graphene material, using the above-mentioned device for measuring the wet specific surface area of ​​a graphene material, comprises the following steps:

[0023] Winding the strip-shaped substrate on the fixed disk for at least one turn, and the strip-shaped substrate can be continuously transported on the fixed disk;

[0024] Introducing a specified amount of electrolyte into the electrolytic tank, and immersing the bottom of the fixed plate in the electrolyte;

[0025] Using the two partitions to separate the internal space of the electrolytic tank;

[0026] Connecting one electrode of an external power supply to the counter electrode, and connecting the other electrode of the external power supply in parallel to the reference electrode and the strip-shaped substrate;

[0027] Power is supplied by a power source, and double-layer capacitance is generated between the portion of the strip-shaped substrate and the counter electrode, and between the counter electrode and the reference electrode within the first chamber, wherein the double-layer capacitance between the strip-shaped substrate and the counter electrode is the measured capacitance, and the capacitance between the counter electrode and the reference electrode is the reference capacitance;

[0028] The strip-shaped substrate is conveyed, and the spraying structure continuously sprays the graphene dispersion onto the strip-shaped substrate, and when the graphene follows the strip-shaped substrate into the electrolyte, a capacitance value to be measured of the graphene and a reference capacitance value at that time are measured;

[0029] Calculate the graphene wet specific surface area by the capacitance value to be measured and the reference capacitance value;

[0030] The strip substrate is continuously conveyed to achieve continuous and dynamic measurement of the graphene wet specific surface area.

[0031] The technical solution of the present invention can achieve the following technical effects:

[0032] By adopting the method of continuous transportation and detection to measure the wet specific surface area of ​​the graphene material in the production process, it is possible to adapt to the real-time quality inspection needs of the continuous production line and ensure that all graphene materials produced in different time periods are sampled. At the same time, the continuous detection method can shorten the single detection cycle; by comparing and measuring the reference capacitance and the detection capacitance, the detection accuracy can be improved and the influence of changes in the properties of the electrolyte or the inherent capacitance of the device on the detection results can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 It is a structural schematic diagram of the present invention;

[0035] Figure 2 This is a schematic diagram of the cross-sectional structure of the electrolytic tank in an embodiment of the present invention;

[0036] Figure 3 1 is a schematic diagram of a partial structure of a strip-shaped substrate in an embodiment of the present invention;

[0037] Figure 4 is a schematic structural diagram of a fixed disk in an embodiment of the present invention;

[0038] Figure 5 yes Figure 4 Rear view structure diagram;

[0039] Figure 6 yes Figure 4 Schematic diagram of the structure viewed from above;

[0040] Figure 7 This is a schematic cross-sectional view of the fixed disk in an embodiment of the present invention;

[0041] Figure 8 2 is a schematic structural diagram of a spraying structure according to an embodiment of the present invention;

[0042] Figure 9 This is a schematic structural diagram of the intermediate cylinder in an embodiment of the present invention;

[0043] Figure 10 2 is a schematic diagram of a cross-sectional structure of a diffusion channel in an embodiment of the present invention;

[0044] Figure 11 This is a schematic diagram of the cross-sectional structure of the intermediate tube in an embodiment of the present invention;

[0045] Figure 12Schematic diagram of the structure of the active disk and the driven disk in an embodiment of the present invention;

[0046] Figure 13 yes Figure 12 Schematic diagram of the structure from another perspective.

[0047] Reference numerals:

[0048] 100, electrolytic tank; 101, separator; 102, first chamber; 103, second chamber; 104, third chamber; 105, counter electrode; 106, reference electrode;

[0049] 200, fixed plate; 201, conveying roller; 202, conductive roller; 203, rubber stopper; 204, buckle cover; 205, negative pressure chamber; 206, air hole; 207, negative pressure tube;

[0050] 300, strip-shaped substrate; 301, conductive area; 302, insulating area;

[0051] 400, spraying structure; 401, intermediate cylinder; 402, diffusion channel; 403, feeding channel; 404, plane area; 405, arc area; 406, narrow mouth area; 407, flat mouth area; 408, air supply channel; 409, pressure regulating valve; 410, rotating column; 411, long groove area; 412, large gear; 413, small gear; 414, large fan gear disc; 415, small fan gear disc; 416, power motor. DETAILED DESCRIPTION

[0052] The technical solutions 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, rather than all the embodiments.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0054] like Figures 1 to 2 As shown, the device for measuring the wet specific surface area of ​​a graphene material of the present invention includes an electrolytic tank 100 for storing an electrolyte, two partitions 101 are provided in the electrolytic tank 100, and the two partitions 101 divide the internal space of the electrolytic tank 100 into a first chamber 102 on the upper side, a second chamber 103 in the middle, and a third chamber 104 on the lower side. The second chamber 103 and the third chamber 104 are respectively provided with a counter electrode 105 and a reference electrode 106;

[0055] A fixed disk 200 is disposed in the first chamber 102 , and a strip substrate 300 is wound and transported on the fixed disk 200 , and the strip substrate 300 is wound around the fixed disk 200 at least once;

[0056] The fixed disk 200 is provided with a spraying structure 400 for spraying a graphene dispersion onto the surface of the strip substrate 300 , and a portion of the fixed disk 200 is immersed in the electrolyte in the first chamber 102 ;

[0057] In the present invention, the electrolytic tank 100 is mainly used to store electrolyte. The opening of the electrolytic tank 100 faces upward, and the fixed disk 200 can be installed at the opening position of the electrolytic tank 100. In order to adapt to the shape of the fixed disk 200, the opening position of the electrolytic tank 100 can be set to an arc-shaped groove. The two partitions 101 in the electrolytic tank 100 can separate the internal space of the electrolytic tank 100, and the separation method is vertical separation, so that three independent spaces are formed in the vertical direction inside the electrolytic tank 100; in the concept of double-layer capacitance, the two charged electrodes in the electrolyte can respectively adsorb cations and anions in the electrolyte, so that the two electrodes are A capacitance pattern is formed between the two electrodes, and a capacitance pattern is also formed between the ions on the two electrodes, thereby realizing the generation of double-layer capacitance. Since the double-layer capacitance is directly related to the effective specific surface area of ​​the material, the specific surface area can be directly calculated by using the ratio of the measured total capacitance to the capacitance per unit area. The capacitance per unit area is generally between 5–25 μF / cm². In actual calculations, 20 μF / cm² can be taken. Of course, the capacitance per unit area under specific temperature and pressure conditions can also be reversely deduced from the specific surface area of ​​the known graphene material, and the derived value can be used to calculate the subsequent graphene material to be tested.

[0058] Since changes in the properties of the electrolyte, such as temperature, ion concentration, etc., or the influence of the inherent capacitance of the device, may interfere with the capacitance measurement value of the graphene during actual measurement, in order to improve the detection accuracy, it is necessary to divide the interior of the electrolytic tank 100 into three chambers, with a detection capacitor formed between the upper chamber and the middle chamber, and a reference capacitor formed between the lower chamber and the middle chamber. That is, the reference capacitance detected between the counter electrode 105 and the reference electrode 106 is used to calibrate the detection capacitance, thereby improving the graphene detection accuracy. During calculation, the reference capacitance is subtracted from the detection capacitance, and the result is divided by the capacitance per unit area to obtain the wet specific surface area value.

[0059] Since the electrolytic tank 100 is vertical in shape and the chambers therein are arranged vertically, with the counter electrode 105 located in the middle chamber, this design can accommodate multifunctional electrode stacking and supports vertical stacking of multiple layers of electrodes, facilitating series or parallel design of multi-step reactions. The vertical structure promotes natural convection of the electrolyte, avoiding dead zones in the bottom region due to gravity deposition in traditional horizontal designs, and ensuring uniform distribution of reactants. The vertical arrangement reduces horizontal footprint and is suitable for industrial scenarios with limited space. The edge effect is reduced, and the electric field distribution in the vertical direction is more uniform, avoiding local over-reaction of the horizontal electrodes due to edge electric field concentration, and improving the data consistency of electrochemical detection, such as wet specific surface area measurement.

[0060] When in use, the fixed disk 200 is fixed on the electrolytic tank 100, and the strip substrate 300 can be wound around the fixed disk 200 for one or more turns for continuous and horizontal transportation. The graphene dispersion in the workshop production process can be directly sprayed onto the strip substrate 300 through the spraying structure 400. The strip substrate 300 can carry the graphene to the bottom of the fixed disk 200. The liquid level of the electrolyte in the electrolytic tank 100 is higher than the bottom of the fixed disk 200, so that the graphene can be immersed in the electrolyte. One pole of the external power supply is connected to the counter electrode 105, and the other pole is connected in parallel to the strip substrate 300 and the reference electrode 106. At this time, the counter electrode 10 5 and the portion of the strip-shaped substrate 300 in the first chamber 102, and between the counter electrode 105 and the reference electrode 106, a double-layer capacitance is formed. The capacitance value between the counter electrode 105 and the strip-shaped substrate 300 is measured as the measured capacitance value, and the capacitance value between the counter electrode 105 and the reference electrode 106 is measured as the reference capacitance value. The measured capacitance value and the reference capacitance value are used to calculate the wet specific surface area of ​​the graphene. Since the strip-shaped substrate 300 is continuously transported, the graphene sample in the production process can be continuously applied to the strip-shaped substrate 300, thereby achieving continuous measurement, which meets the detection requirements of continuous production in the workshop.

[0061] In actual operation, the device also needs to be equipped with various conventional auxiliary structures such as a power supply, a capacitance detector, a controller, and circuits to meet measurement requirements. The conveyance of the strip substrate 300 can be completed by a release roller and a take-up roller. After use, the strip substrate 300 can be replaced. The strip substrate 300 can be made of low-cost materials and does not need to be cleaned and reused, thus avoiding waste of resources and costs during cleaning. Since the separator 101 needs to take into account ion conductivity, chemical stability, mechanical strength and cost-effectiveness, the separator 101 can be made of materials such as polyolefin, polytetrafluoroethylene, ceramic diaphragm, glass fiber, perfluorosulfonic acid ion exchange membrane, etc.

[0062] By adopting the method of continuous transportation and detection to measure the wet specific surface area of ​​the graphene material in the production process, it is possible to adapt to the real-time quality inspection needs of the continuous production line and ensure that all graphene materials produced in different time periods are sampled. At the same time, the continuous detection method can shorten the single detection cycle; by comparing and measuring the reference capacitance and the detection capacitance, the detection accuracy can be improved and the influence of changes in the properties of the electrolyte or the inherent capacitance of the device on the detection results can be avoided.

[0063] Since the strip-shaped substrate 300 needs to serve as a carrier for graphene, it needs to have the characteristics of high porosity, good flexibility, high strength, light weight, and high conductivity to meet measurement requirements. There are many materials with the above characteristics. Specifically, the strip-shaped substrate 300 is one of carbon paper, carbon nanofiber, and metal foam with an intermediate layer, and the intermediate layer is at least one of titanium mesh, stainless steel mesh, and aramid.

[0064] In addition to the above materials, the strip substrate 300 can also be made of materials such as activated carbon-coated metal foil, metal mesh, and composite film, all of which can meet the requirements of use; the provision of the intermediate layer can enhance the flexibility and strength of the strip substrate 300 itself, thereby preventing the strip substrate 300 from breaking during transportation; of course, in order to improve the strength of the strip substrate 300, it is also possible to apply carbon nanocoating or conductive polymers and other materials on the surface of the strip substrate 300.

[0065] When the strip substrate 300 is energized, if the entire strip substrate 300 is conductive, the electrical energy will be transferred to other structures along the strip substrate 300, causing power loss and non-concentration of electrode charge, affecting measurement accuracy. Therefore, the electrical energy on the strip substrate 300 needs to be concentrated at the position immersed in the electrolyte. To achieve this effect, Figure 3 As shown, the strip-shaped substrate 300 is composed of a plurality of conductive regions 301 and a plurality of insulating regions 302 that are sequentially and staggered. The spraying structure 400 sprays the graphene dispersion onto the conductive regions 301, or onto the conductive regions 301 and the insulating regions 302. The insulating regions 302 can be used to separate two adjacent conductive regions 301. Therefore, when power is applied, only one conductive region 301 located at the bottom of the fixed plate 200 needs to be energized, while the other conductive regions 301 are in an off state. In this way, the electrical energy is concentrated on the conductive region 301 located in the electrolyte, thereby improving the capacitance detection accuracy and thus improving the measurement accuracy of the wet specific surface area.

[0066] In actual use, the spraying structure 400 can apply the graphene material only on several conductive areas 301, that is, the spraying structure 400 performs intermittent application, which can avoid the graphene material being applied on the insulating area 302 and causing waste; of course, the spraying structure 400 can also adopt a continuous spraying method to apply the graphene material on the conductive area 301 and the insulating area 302, so that the spraying structure 400 can perform continuous spraying without the need for intermittent control, simplifying the operation method and supporting control structure, but this method will cause a small amount of waste of graphene material, so which method to choose can be determined according to actual conditions; since the amount of graphene material applied on the strip substrate 300 is small, even if the graphene material is applied on the insulating area 302, the amount of electrical energy conducted through the graphene material on the insulating area 302 is small, which will not cause significant interference to the measurement work, and in actual operation, the conduction loss of this part of the electrical energy can also be compensated in the calculation process.

[0067] When the strip substrate 300 is transported on the fixed plate 200, in order to reduce the friction between the strip substrate 300 and the fixed plate 200, the following method can be used: Figure 2 and Figure 6 In the embodiment shown, a plurality of conveying rollers 201 are rotatably provided on the outer wall of the fixed plate 200, and a conductive roller 202 is rotatably provided on the bottom of the fixed plate 200. The conductive roller 202 is connected to an external power source, and rubber stoppers 203 are provided at both ends of the conductive roller 202.

[0068] The plurality of conveyor rollers 201 on the fixed disk 200 assist in conveying the strip-shaped substrate 300. Since the strip-shaped substrate 300 is wound and conveyed on the fixed disk 200, the strip-shaped substrate 300 needs to slide relative to the conveyor rollers 201 and the fixed disk 200 along the axis of the fixed disk 200. The conductive roller 202 is connected to an external power source. When the conductive roller 202 is energized, it transfers electrical energy to the conductive area 301 in contact with it, thereby achieving electrical energy transmission. When the conductive area 301 separates from the conductive roller 202, the next conductive area 301 moves to the conductive roller 202 position and reconnects electrically. This allows each conductive area 301 immersed in the electrolyte to be individually energized.

[0069] Since the strip substrate 300 needs to move relative to the fixed plate 200 along the axis direction of the fixed plate 200 , the rubber stoppers 203 provided at both ends of the conductive roller 202 can guide and position the strip substrate 300 so that the strip substrate 300 can be smoothly transported on the fixed plate 200 .

[0070] Based on the above implementation, when the spraying structure 400 sprays graphene onto the strip substrate 300, the graphene dispersion will only adhere to the surface of the strip substrate 300 and cannot enter the interior of the strip substrate 300, which easily causes the graphene to have an uneven thickness distribution or agglomerate on the strip substrate 300, and the internal space of the strip substrate 300 cannot be effectively utilized. To improve this phenomenon, the following method can be used: Figures 4 to 7 In the structure shown, a buckle cover 204 is provided on the fixed plate 200, the buckle cover 204 is buckled on a portion of the strip-shaped base 300 on the fixed plate 200, and the spraying structure 400 is installed on the buckle cover 204;

[0071] A negative pressure chamber 205 corresponding to the buckle cover 204 is provided in the fixed plate 200, and a plurality of air holes 206 communicating with the negative pressure chamber 205 are provided on the outer wall of the fixed plate 200;

[0072] The spraying structure 400 can spray the graphene dispersion into the buckle cover 204 to prevent the dispersion from being wasted by diffusion in the air; since the negative pressure chamber 205 is under negative pressure, the gas in the buckle cover 204 can pass through the strip substrate 300 and the air holes 206 and enter the negative pressure chamber 205. At this time, the gas can carry the dispersion in the spraying structure 400 toward the outer surface of the strip substrate 300, so that the dispersion adheres to the surface of the strip substrate 300. In addition, when the gas passes through the strip substrate 300, the dispersion can be diffused inside the strip substrate 300. The strip substrate 300 intercepts the dispersion, so that the dispersion fills the surface and inside of the strip substrate 300, increasing the diffusion area of ​​the dispersion, increasing the load and specific surface area of ​​the dispersion on the strip substrate 300, and at the same time improving the permeability of the electrolyte in the strip substrate 300.

[0073] A negative pressure tube 207 connected to the negative pressure chamber 205 is provided on the side wall of the fixed disk 200. As the strip substrate 300 is continuously transported, the several conductive areas 301 on the strip substrate 300 will pass through the buckle cover 204 in sequence. The negative pressure tube 207 needs to continuously extract the air inside the negative pressure chamber 205 to achieve the conditions and effect of providing vacuum penetration for each conductive area 301.

[0074] Based on the above implementation, Figures 8 to 10 As shown, the spraying structure 400 includes an intermediate cylinder 401 and a diffusion channel 402 and a feed channel 403 connected and mounted on the intermediate cylinder 401. A rotating body is provided in the intermediate cylinder 401 for controlling the connection or disconnection between the diffusion channel 402 and the feed channel 403.

[0075] The diffusion channel 402 has a flat opening area 407 communicating with the buckle cover 204. The upper surface of the diffusion channel 402 is a flat area 404, and the lower surface of the diffusion channel 402 is a concave arc area 405. The distance between the flat area 404 and the arc area 405 gradually decreases in the direction toward the buckle cover 204 and then gradually increases.

[0076] In the present invention, the graphene dispersion is introduced into the intermediate cylinder 401 through the feeding channel 403, and the dispersion in the intermediate cylinder 401 is then introduced into the buckle cover 204 through the diffusion channel 402, thereby realizing the conveying of the dispersion; the shape setting of the diffusion channel 402 can make the dispersion achieve the purpose of diffusion spraying after passing through the diffusion channel 402, thereby improving the adhesion uniformity of the dispersion on the strip substrate 300; as for the specific structure of the diffusion channel 402, a deformed channel can be formed in the diffusion channel 402 by utilizing the plane area 404 and the arc area 405. Figure 10 At the narrow opening region 406 shown, the channel diameter is minimized. When the dispersion passes through this channel, the Bernoulli force is applied to increase the flow rate of the fluid passing through the narrow opening, thereby increasing the flow rate of the dispersion through the diffusion channel 402. This facilitates the dispersion to be sprayed and dispersed when it enters the buckle cover 204 through the flat opening region 407. The flat opening region 407 can increase the dispersion diffusion area. Furthermore, based on the shape characteristics of the arc-shaped region 405 and the flat region 404, the dispersion passing through the flat opening region 407 can be diffused toward the surface of the strip-shaped substrate 300, thereby simultaneously achieving a drainage effect on the dispersion.

[0077] When the dispersion needs to be attached only to the conductive area 301, the conveying of the dispersion can be controlled by the rotating body, that is, when the insulating area 302 is located in the buckle cover 204, the conveying of the dispersion stops, or the opening and closing control of the rotating body is used to make the dispersion sprayed into the buckle cover 204 intermittently.

[0078] In order to enhance the diffusion effect of the dispersion, pneumatic assisted diffusion can be used, such as Figures 8 and 9 As shown, the diffusion channel 402 and the feed channel 403 are staggered along the axis of the intermediate cylinder 401. An air supply channel 408 is provided at one end of the intermediate cylinder 401 close to the feed channel 403. A pressure regulating valve 409 is provided on the air supply channel 408.

[0079] The rotating body synchronously controls the air supply channel 408 to be connected or disconnected with the intermediate cylinder 401;

[0080] High-pressure air can be introduced into the intermediate cylinder 401 through the air supply channel 408. The high-pressure air in the intermediate cylinder 401 can push the dispersion liquid in the intermediate cylinder 401 to be sprayed into the buckle cover 204 through the diffusion channel 402, thereby utilizing the air flow diffusion effect to diffuse the dispersion liquid. Since the high-pressure air and the dispersion liquid need to be introduced into the same intermediate cylinder 401 through the air supply channel 408 and the feed channel 403, a rotating body is required to separate the air supply channel 408 and the feed channel 403 to prevent them from communicating with each other. The pressure regulating valve 409 can adjust the pressure of the high-pressure air entering the intermediate cylinder 401.

[0081] In some embodiments, in order to quickly dry the dispersion on the strip base 300, the high-pressure air can be a high-temperature gas. The high temperature of the gas is used to dry the dispersion on the strip base 300, and the gas can pass through the strip base 300, thereby also having a drying effect on the dispersion inside the strip base 300. It should be pointed out that since the dispersion is dispersed in the buckle cover 204, the high-temperature airflow is more likely to effectively disperse the dispersion. Since the dispersion in the intermediate cylinder 401 and the diffusion channel 402 is relatively concentrated and is in a confined space, the high-temperature airflow can only dry it. It has the effect of blowing and dispersing, but cannot have an effective drying effect, thus avoiding the dispersion from drying and solidifying in the intermediate cylinder 401 and the diffusion channel 402; in addition, since the inside of the buckle cover 204 is at negative pressure, a vacuum drying effect can be achieved; to ensure that the inside of the buckle cover 204 is in a negative pressure state, the difference between the blocking pressure of the air in the air supply channel 408 by the pressure regulating valve 409 and the delivery pressure of the air in the air supply channel 408 is smaller than the negative pressure value inside the buckle cover 204, that is, the air is sucked from the air supply channel 408 into the intermediate cylinder 401 by using the negative pressure, thereby ensuring that the inside of the buckle cover 204 is in a negative pressure state.

[0082] Based on the above embodiments, Figure 11 As shown, the rotating body is a rotating column 410, which has a long groove area 411. The diffusion channel 402 and the air supply channel 408 are located on the same side of the axis of the intermediate cylinder 401, and the air supply channel 408 and the material supply channel 403 are located on both sides of the axis of the intermediate cylinder 401. During the rotation of the rotating column 410, the long groove area 411 is alternately connected to the air supply channel 408 or the material supply channel 403;

[0083] The rotating column 410 is in a rotating state in the intermediate cylinder 401. When the long groove area 411 on the rotating column 410 rotates to the position of the feeding channel 403, the dispersion in the feeding channel 403 can be filled into the long groove area 411. When the long groove area 411 rotates to the position of the diffusion channel 402, the air supply channel 408 is synchronously connected with the long groove area 411. At this time, the air discharged from the air supply channel 408 will enter the long groove area 411 and push the dispersion into the buckle cover 204. Thus, with the rotation of the rotating column 410, the intermittent supply of the dispersion is realized, and the feeding channel 403 is prevented from being connected with the air supply channel 408 or the diffusion channel 402. When in use, since the air supply channel 408 and the diffusion channel 402 are located on the same side of the axis of the rotating column 410, the air discharged into the long groove area 411 through the air supply channel 408 can blow the dispersion clean. The air supply is still continued until the air supply operation reaches the predetermined time, which can facilitate the drying process of the dispersion on the strip substrate 300. It should be pointed out that, since there is air inside the long trough area 411 when the long trough area 411 rotates to the position of the feeding channel 403, the air originally in the long trough area 411 needs to be discharged when the feeding channel 403 introduces the dispersion into the long trough area 411. The discharge method can be to discharge it through the gap between the rotating column 410 and the intermediate cylinder 401, or to connect a return pipe to the intermediate cylinder 401. The return pipe and the feeding channel 403 are located on the same side of the axis of the intermediate cylinder 401. The dispersion discharged into the long trough area 411 by the feeding channel 403 can be refluxed through the return pipe. Therefore, the air in the long trough area 411 can also be discharged through the return pipe. Of course, other methods can also be used to eliminate the influence of air on the introduction of the dispersion.

[0084] In some embodiments, the cross-section of the air supply channel 408 can be set to be fan-shaped, so that when the rotating column 410 rotates, as the overlapping position of the long groove area 411 and the air supply channel 408 gradually increases, the air discharged into the long groove area 411 by the air supply channel 408 can gradually blow the dispersion in the long groove area 411 into the buckle cover 204, that is, the dispersion is gradually diffused into the buckle cover 204, and the air will not directly and massively push the dispersion into the buckle cover 204, causing the dispersion to be unable to effectively diffuse.

[0085] Based on the above embodiments, Figure 12 and Figure 13 As shown, the spraying structure 400 further includes a power unit for providing power for the rotation of the rotating column 410;

[0086] The power unit includes a driving disc and a driven disc. The driven disc is in driving connection with the rotating column 410. The driving disc includes a coaxial large gear 412 and a small gear 413. The driven disc includes a coaxial large sector gear disc 414 and a small sector gear disc 415. The large sector gear disc 414 and the small sector gear disc 415 are staggered in the circumferential direction. The large gear 412 and the small sector gear disc 415 are used in conjunction with each other, and the small gear 413 is used in conjunction with the large sector gear disc 414.

[0087] The driving disc is in transmission connection with one of the large sector toothed disc 414 or the small sector toothed disc 415 in the driven disc;

[0088] In the present invention, the length of the conductive area 301 is generally set to be greater than the length of the insulating area 302, which can increase the detection amount of the dispersion. Therefore, within one rotation cycle of the rotating column 410, the time when the long groove area 411 corresponds to the position of the diffusion channel 402 is greater than the time when the long groove area 411 corresponds to the position of the feeding channel 403. However, the rotating column 410 needs to isolate the air supply channel 408 from the feeding channel 403. Therefore, when the rotating column 410 rotates at a constant speed, the time when the long groove area 411 corresponds to the position of the diffusion channel 402 is less than the time when the long groove area 411 corresponds to the position of the feeding channel 403. This will cause inconsistency. To avoid this phenomenon, it is necessary to control the rotation speed of the rotating column 410, that is, when the long groove area 411 corresponds to the position of the diffusion channel 402, the rotating column 410 10's rotation speed should be slow, and the rotation speed of the rotating column 410 should be fast when the long groove area 411 corresponds to the position of the feeding channel 403. To achieve this purpose, the active disk and the driven disk in the above-mentioned structural method can be used. The active disk can rotate at a uniform speed, and its power can be provided by the power motor 416. When the small gear 413 and the large fan toothed disk 414 are engaged and transmitted, the driven disk rotates at a slower speed, and the rotation speed of the rotating column 410 is reduced accordingly. When the large gear 412 and the small fan toothed disk 415 are engaged and transmitted, the driven disk rotates at a faster speed, and the rotation speed of the rotating column 410 is faster. In some embodiments, the power motor 416 can also be directly used to provide power to the driven disk. However, this method requires the rotation speed of the power motor 416 to be alternately changed between fast and slow, which can easily cause damage to the power motor 416, and the operation method is cumbersome.

[0089] The method for measuring the wet specific surface area of ​​a graphene material, using the above-mentioned device for measuring the wet specific surface area of ​​a graphene material, comprises the following steps:

[0090] The strip-shaped substrate 300 is wound on the fixed disk 200 at least once, and the strip-shaped substrate 300 can be continuously transported on the fixed disk 200;

[0091] A predetermined amount of electrolyte is introduced into the electrolytic tank 100, and the bottom of the fixed plate 200 is immersed in the electrolyte;

[0092] The internal space of the electrolytic tank 100 is divided by two partitions 101;

[0093] Connect one electrode of the external power supply to the counter electrode 105, and connect the other electrode of the external power supply in parallel to the reference electrode 106 and the strip substrate 300;

[0094] When the power supply is supplied, double-layer capacitance is generated between the portion of the strip substrate 300 and the counter electrode 105, and between the counter electrode 105 and the reference electrode 106 in the first chamber 102. The double-layer capacitance between the strip substrate 300 and the counter electrode 105 is the measured capacitance, and the capacitance between the counter electrode 105 and the reference electrode 106 is the reference capacitance.

[0095] The strip substrate 300 is conveyed, and the spraying structure 400 continuously sprays the graphene dispersion onto the strip substrate 300. When the graphene follows the strip substrate 300 into the electrolyte, the capacitance value to be measured of the graphene and the reference capacitance value at this time are measured;

[0096] Calculate the graphene wet specific surface area by the capacitance value to be measured and the reference capacitance value;

[0097] The strip substrate 300 is continuously conveyed to achieve continuous and dynamic measurement of the graphene wet specific surface area.

[0098] Using the above method, continuous measurement of graphene in the workshop production process can be achieved, thereby incorporating the graphene detection work into the production line, and the above detection method can correct the capacitance to be measured based on the reference capacitance, thereby making the measurement value of the wet specific surface area of ​​the graphene material more accurate and improving the detection accuracy.

[0099] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for measuring the wet specific surface area of ​​a graphene material, characterized in that: An electrolytic tank (100) for storing an electrolyte is provided with two partitions (101) in the electrolytic tank (100), and the two partitions (101) divide the internal space of the electrolytic tank (100) into a first chamber (102) at the upper side, a second chamber (103) in the middle, and a third chamber (104) at the lower side. The second chamber (103) and the third chamber (104) are respectively provided with a counter electrode (105) and a reference electrode (106); A fixed disk (200) is provided in the first chamber (102), a strip-shaped substrate (300) is wound and transported on the fixed disk (200), and the strip-shaped substrate (300) is wound around the fixed disk (200) at least once; The fixed disk (200) is provided with a spraying structure (400) for spraying a graphene dispersion onto the surface of the strip-shaped substrate (300), and a portion of the fixed disk (200) is immersed in the electrolyte in the first chamber (102); The strip-shaped substrate (300) is composed of a plurality of conductive areas (301) and a plurality of insulating areas (302) that are sequentially and staggeredly connected, and the spraying structure (400) sprays the graphene dispersion onto the conductive areas (301), or onto the conductive areas (301) and the insulating areas (302); A plurality of conveying rollers (201) are rotatably provided on the outer wall of the fixed disk (200), a conductive roller (202) is rotatably provided on the bottom of the fixed disk (200), and the conductive roller (202) is connected to an external power supply. Both ends of the conductive roller (202) are provided with rubber retaining edges (203); A detection capacitor is formed between the first chamber (102) and the second chamber (103), and a reference capacitor is formed between the third chamber (104) and the second chamber (103); The liquid level of the electrolyte in the electrolytic tank (100) is higher than the bottom of the fixed plate (200), the graphene is immersed in the electrolyte, one pole of the external power supply is connected to the counter electrode (105), and the other pole is connected in parallel to the strip substrate (300) and the reference electrode (106), and double-layer capacitance is formed between the counter electrode (105) and a portion of the strip substrate (300) in the first chamber (102), and between the counter electrode (105) and the reference electrode (106).

2. The device for measuring the wet specific surface area of ​​a graphene material according to claim 1, wherein: The strip-shaped substrate (300) is one of carbon paper, carbon nanofiber, and metal foam with an intermediate interlayer, and the intermediate interlayer is at least one of titanium mesh, stainless steel mesh, and aramid.

3. The device for measuring the wet specific surface area of ​​a graphene material according to claim 1, wherein: A buckle cover (204) is provided on the fixed disk (200), the buckle cover (204) is buckled on a portion of the strip-shaped base (300) on the fixed disk (200), and the spraying structure (400) is installed on the buckle cover (204); A negative pressure chamber (205) corresponding to the buckle cover (204) is provided in the fixed disk (200), and a plurality of air holes (206) communicating with the negative pressure chamber (205) are provided on the outer wall of the fixed disk (200).

4. The device for measuring the wet specific surface area of ​​a graphene material according to claim 3, wherein: The spraying structure (400) comprises an intermediate cylinder (401) and a diffusion channel (402) and a feed channel (403) connected and mounted on the intermediate cylinder (401). A rotating body is provided in the intermediate cylinder (401) for controlling the connection or disconnection between the diffusion channel (402) and the feed channel (403). The diffusion channel (402) has a flat mouth area (407) connected to the buckle cover (204), the upper surface of the diffusion channel (402) is a plane area (404), and the lower surface of the diffusion channel (402) is a concave arc area (405), and the distance between the plane area (404) and the arc area (405) gradually decreases in the direction toward the buckle cover (204) and then gradually increases.

5. The device for measuring the wet specific surface area of ​​a graphene material according to claim 4, wherein: The diffusion channel (402) and the material supply channel (403) are staggered along the axis of the intermediate cylinder (401); an air supply channel (408) is provided at one end of the intermediate cylinder (401) close to the material supply channel (403); and a pressure regulating valve (409) is provided on the air supply channel (408); The rotating body synchronously controls the air supply channel (408) to be connected or disconnected with the intermediate cylinder (401).

6. The device for measuring the wet specific surface area of ​​a graphene material according to claim 5, characterized in that: The rotating body is a rotating column (410), and the rotating column (410) has a long groove area (411). The diffusion channel (402) and the air supply channel (408) are located on the same side of the axis of the intermediate cylinder (401), and the air supply channel (408) and the material supply channel (403) are located on both sides of the axis of the intermediate cylinder (401). During the rotation of the rotating column (410), the long groove area (411) is alternately connected to the air supply channel (408) or the material supply channel (403).

7. The device for measuring the wet specific surface area of ​​a graphene material according to claim 6, characterized in that: The spraying structure (400) further includes a power unit for providing power for the rotation of the rotating column (410); The power unit comprises a driving disc and a driven disc, the driven disc being in driving connection with the rotating column (410), the driving disc comprising a coaxial large gear (412) and a small gear (413), the driven disc comprising a coaxial large sector gear disc (414) and a small sector gear disc (415), and the large sector gear disc (414) and the small sector gear disc (415) are staggered in the circumferential direction, the large gear (412) and the small sector gear disc (415) are used in conjunction with each other, and the small gear (413) and the large sector gear disc (414) are used in conjunction with each other; The driving disc is in transmission connection with one of the large sector toothed disc (414) or the small sector toothed disc (415) in the driven disc.

8. A method for measuring the wet specific surface area of ​​a graphene material, comprising: The steps include: The strip-shaped substrate (300) is wound on the fixed disk (200) at least once, and the strip-shaped substrate (300) can be continuously transported on the fixed disk (200); A prescribed amount of electrolyte is introduced into the electrolytic tank (100), and the bottom of the fixed plate (200) is immersed in the electrolyte; The internal space of the electrolytic tank (100) is divided by the two partitions (101); Connecting one electrode of an external power source to the counter electrode (105), and connecting the other electrode of the external power source in parallel to the reference electrode (106) and the strip-shaped substrate (300); Power is supplied, and double-layer capacitance is generated between the portion of the strip-shaped substrate (300) and the counter electrode (105), and between the counter electrode (105) and the reference electrode (106) in the first chamber (102), wherein the double-layer capacitance between the strip-shaped substrate (300) and the counter electrode (105) is the capacitance to be measured, and the capacitance between the counter electrode (105) and the reference electrode (106) is the reference capacitance; The strip-shaped substrate (300) is transported, and the spraying structure (400) continuously sprays the graphene dispersion onto the strip-shaped substrate (300); when the graphene follows the strip-shaped substrate (300) and moves into the electrolyte, the capacitance value to be measured of the graphene and the reference capacitance value at that time are measured; The wet specific surface area of ​​graphene is calculated by comparing the measured capacitance value with the reference capacitance value. Specifically, the wet specific surface area value is obtained by subtracting the reference capacitance from the measured capacitance and then dividing the result by the capacitance per unit area. The capacitance per unit area value is between 5–25 μF / cm². The strip-shaped substrate (300) is continuously conveyed to achieve continuous and dynamic measurement of the graphene wet specific surface area.

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