A device and method for continuous demetallization of supercapacitor activated carbon

Abstract

The present disclosure relates to a device and method for continuous demetallization of supercapacitor activated carbon, which comprises an outer shell arranged in the horizontal direction along the axis, and a filter membrane and an inner shell arranged in turn inwardly from the outer shell and coaxially with the outer shell, each of the outer shell, the filter membrane and the inner shell being independently cylindrical; a first cylindrical cavity is formed between the outer shell and the filter membrane; a first partition, a second partition, a third partition and a fourth partition are provided on the outer shell to sequentially divide the first cylindrical cavity into an impregnation zone, an acid pickling zone, a water washing zone and a discharge zone; a plurality of filtrate channels are arranged in the second cylindrical cavity. The device can realize continuous purification of supercapacitor activated carbon crude products, and has the advantages of simple device, high efficiency, small floor area, short process flow, easy operation and high production capacity.

Description

Technical Field

[0001] This disclosure relates to the field of carbon materials technology, and more specifically, to an apparatus and method for continuous demetallization of activated carbon in supercapacitors. Background Technology

[0002] Supercapacitors possess characteristics such as high power density, rapid charge and discharge, long cycle life, and safety and reliability, leading to their widespread application in both military and civilian fields. The energy storage performance of supercapacitors largely depends on the electrode materials. Heavy oil, a complex mixture of numerous aliphatic hydrocarbons, cycloalkanes, and polycyclic aromatic hydrocarbons, exhibits complex and multi-layered composition and structure. It contains a large number of aromatic structures and abundant heteroatoms such as S, N, P, and O, making it an excellent precursor for activated carbon in supercapacitors.

[0003] Compared to ordinary activated carbon, the indicator system for supercapacitor activated carbon is more complex and has higher requirements, especially regarding ash content and metallic impurities, where the requirements are more stringent. Metallic impurities in the carbon-based materials of supercapacitor electrode activated carbon mainly originate from two sources: firstly, inherent in the raw materials, such as the metallic impurities contained in coconut shells, coal, petroleum coke, and asphalt used as carbon sources; secondly, introduced during the preparation process, such as activators like KOH and ZnCl2, and Fe, Ni, and Co introduced during reactor wall corrosion. Currently, the commonly used method for removing metallic impurities from supercapacitor activated carbon is an intermittent process of acid washing followed by water washing. Typically, the crude product is immersed in hydrochloric acid, nitric acid, sulfuric acid, or hydrofluoric acid solutions, combined with stirring, aeration, pressurization, and the addition of chelating agents to promote the penetration, diffusion, and reaction dissolution of impurities into the porous structure, removing them as metal salts. Afterwards, repeated water washing and pressure filtration, along with pH adjustment, remove Cl... - SO4 2- NO3 - F -Ions. Patent CN112537772A discloses a method for preparing supercapacitor materials. In the purification process, the crude product is thoroughly mixed with HCl and acetic acid solutions at a certain temperature in a batch reactor, causing metal ions to form soluble salts. The initial activated carbon product is then repeatedly washed with water and filtered using a plate and frame filter press until the filtrate's pH value and chloride ion residue are within acceptable limits. However, this method has a long overall purification process, involving acid washing, filtration, multiple water washings, and multiple filtrations, each step taking more than 2 hours, resulting in low processing efficiency and severely limited production capacity. To improve purification efficiency, patent CN115394566A discloses a purification method for supercapacitor electrode activated carbon-based materials, which optimizes the acid washing components by using a hydrochloric acid-alcohol solution (an organic solvent containing HCl and HF) instead of the traditional dilute acid aqueous solution impregnation. Hydrochloric acid-alcohol solution has low surface tension, allowing it to effectively penetrate and diffuse into micropores, mesopores, capillaries, complex irregular surfaces, high aspect ratio structures, and difficult-to-wet substrates in carbon-based materials. This facilitates full contact and reaction between the acid and impurities. After several washes with deionized water and drying, a high-purity carbon-based material with ultra-low impurity content is obtained: total ash <0.5%, Fe, Ni, and Zn <20 ppm. Patent CN115385335A discloses a supercritical cleaning method for deep purification of porous carbon materials for supercapacitors, specifically a method using supercritical CO2 cleaning to deeply remove metallic and non-metallic impurities from porous carbon materials used in supercapacitor energy storage. TBP(HNO3) is used as an example. x (H2O) y TBP(HF) x (H2O) y and TBP(HCl) x (H2O) y The cleaning agent is transported to the difficult-to-wet surface, pore ports and interior of the porous carbon material used for supercapacitor energy storage via supercritical CO2, and reacts with metallic and non-metallic impurities to generate cleaning byproducts dissolved in supercritical CO2, thus removing impurities more thoroughly.

[0004] In summary, existing intermittent demetallization processes suffer from low efficiency, large footprint, and limited capacity. Current technological developments to improve the purification efficiency and capacity of activated carbon in supercapacitors mainly focus on improving the acidic components in the acid washing process and the contact method, without optimizing the purification process and equipment from an overall process perspective. Consequently, problems such as complex and discontinuous purification processes persist. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides an apparatus and method for continuous demetallization of activated carbon for supercapacitors. This apparatus enables continuous purification of crude activated carbon products for supercapacitors, and is simple, efficient, space-saving, has a short process flow, is easy to operate, and has a high production capacity.

[0006] To achieve the above objectives, the first aspect of this disclosure provides a device for continuous demetallization of activated carbon in supercapacitors. The device includes an outer shell arranged axially in a horizontal direction, and a filter membrane and an inner shell arranged sequentially from the outer shell and coaxial with the outer shell. The outer shell, the filter membrane, and the inner shell are each independently cylindrical. A first cylindrical cavity is formed between the outer shell and the filter membrane; a first partition, a second partition, a third partition, and a fourth partition are provided on the outer shell to divide the first cylindrical cavity into an immersion zone, an acid pickling zone, a water washing zone, and a discharge zone in sequence; a first pure water inlet is provided on the outer shell corresponding to the immersion zone and near the first partition, an acidic solution inlet is provided on the outer shell corresponding to the acid pickling zone and near the second partition, and a second pure water inlet is provided on the outer shell corresponding to the water washing zone and near the third partition; multiple baffles are provided on the filter membrane and located inside the first cylindrical cavity; A second cylindrical cavity is formed between the filter membrane and the inner shell. Multiple filtrate channels are provided in the second cylindrical cavity. The inlet of each filtrate channel is connected to the filter membrane, and the outlet of each filtrate channel is connected to the filtrate outlet of the inner shell. The device further includes a driving device for driving the filter membrane and the inner shell to rotate together and drive the rotation of each baffle and each filtrate channel; in the state of rotation or non-rotation, the first separator, the second separator, the third separator and the fourth separator each independently contact at least one baffle.

[0007] Optionally, the central angle corresponding to the immersion zone is 60-90°, the central angle corresponding to the pickling zone is 120-180°, the central angle corresponding to the washing zone is 60-90°, and the central angle corresponding to the discharge zone is greater than 0° and less than 120°.

[0008] Optionally, the aspect ratio of the outer shell is (1-5):1, the aspect ratio of the filter membrane is (2-6):1, and the aspect ratio of the inner shell is (5-25):1. Preferably, the ratio of the diameters of the outer shell, the filter membrane, and the inner shell is (5-6):(4-5):1.

[0009] Optionally, the height of each baffle is less than the distance between the outer housing and the filter membrane.

[0010] Optionally, the distance between adjacent baffles is less than the width of each of the first, second, third, and fourth partitions.

[0011] Optionally, the device further includes a Z-shaped scraper, which includes an upper scraper, an intermediate receiving plate, and a lower draining plate, wherein the upper scraper and the lower draining plate are respectively disposed at both ends of the intermediate receiving plate; The upper scraper is vertically connected to the intermediate receiving plate and is located in the first cylindrical cavity; The lower guide plate is movably connected to the intermediate receiving plate and is located at the discharge port on the outer shell corresponding to the discharge area.

[0012] A second aspect of this disclosure provides a method for continuous demetallization of activated carbon in supercapacitors, the method comprising the following steps: S1. Turn on the drive device to drive the filter membrane and inner shell to rotate together and drive each baffle and each filtrate channel to rotate. S2. The crude activated carbon product for supercapacitors and impregnation water are introduced into the impregnation zone through the first pure water inlet for impregnation treatment to obtain the first material. S3. The acidic solution enters the pickling zone through the acidic solution inlet, and under the rotation drive of each baffle, the first material enters the pickling zone and comes into contact with the acidic solution for pickling treatment to obtain the second material. S4. The washing water enters the washing zone through the second pure water inlet, and the second material enters the washing zone and comes into contact with the washing water for washing under the rotation drive of each baffle. The resulting third material is discharged from the discharge port of the discharge zone under the rotation drive of each baffle.

[0013] Optionally, in step S1, the rotational speed is 0.1-3.0 r / h; In step S2, the weight ratio of the crude activated carbon product for the supercapacitor to the impregnation water is 1:(3-8), and the impregnation time is 15-60 min. In step S3, the weight ratio of the first material to the acidic solution is 1:(3-5), and the pickling time is 30-120 min. In step S4, the weight ratio of the second material to the washing water is 1:(4-8), and the washing time is 15-60 min.

[0014] Optionally, the mass concentration of the acidic solution is 5-7%, and the acidic solution is selected from at least one of hydrochloric acid, sulfuric acid, and nitric acid.

[0015] Optionally, the method further includes: drying and grinding the discharged third material to obtain supercapacitor activated carbon.

[0016] Through the above technical solution, the device disclosed herein can realize the continuous purification of crude activated carbon products for supercapacitors, and the device has the advantages of high efficiency, small footprint, short process flow, convenient operation, and high production capacity.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the device for continuous demetallization of activated carbon in a supercapacitor disclosed herein.

[0019] Explanation of reference numerals in the attached figures 1. First pure water inlet; 2. Acidic solution inlet; 3. Second pure water inlet; 4. Z-shaped scraper; 5 First partition; 6 Second partition; 7 Third partition; 8. Fourth separator; 9. Baffle; 10. Outer shell; 11. Filter membrane; 12 Filtration channel; 13 Filtration outlet; 14 Inner shell. Detailed Implementation

[0020] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0021] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" refer to the outline of the device. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] like Figure 1 As shown, the first aspect of this disclosure provides a device for continuous demetallization of activated carbon in supercapacitors. The device includes an outer shell 10 arranged axially in a horizontal direction, and a filter membrane 11 and an inner shell 14 arranged sequentially inward from the outer shell 10 and coaxial with the outer shell 10. The outer shell 10, the filter membrane 11 and the inner shell 14 are each independently cylindrical. A first cylindrical cavity is formed between the outer shell 10 and the filter membrane 11. A first separator 5, a second separator 6, a third separator 7, and a fourth separator 8 are provided on the outer shell 10 to divide the first cylindrical cavity into an immersion zone, an acid pickling zone, a water washing zone, and a discharge zone in sequence. A first pure water inlet 1 is provided on the outer shell 10 corresponding to the immersion zone and near the first separator 5. An acidic solution inlet 2 is provided on the outer shell 10 corresponding to the acid pickling zone and near the second separator 6. A second pure water inlet 3 is provided on the outer shell 10 corresponding to the water washing zone and near the third separator 7. Multiple baffles 9 are provided on the filter membrane 11 and located inside the first cylindrical cavity. A second cylindrical cavity is formed between the filter membrane 11 and the inner shell 14. A plurality of filtrate channels 12 are provided in the second cylindrical cavity. The inlet of each filtrate channel 12 is connected to the filter membrane 11, and the outlet of each filtrate channel 12 is connected to the filtrate outlet 13 of the inner shell 14. The device further includes a driving device for driving the filter membrane 11 and the inner housing 14 to rotate together and drive the rotation of each baffle 9 and each filtrate channel 12; in the state of rotation or non-rotation, the first separator 5, the second separator 6, the third separator 7 and the fourth separator 8 each independently contact at least one baffle 9.

[0023] In this disclosure, the continuous demetallization device for activated carbon in supercapacitors is a horizontal device. The device employs a zoned design, dividing the first cylindrical cavity into an impregnation zone, an acid washing zone, a water washing zone, and a discharge zone. This enables integrated impregnation, acid washing, and water washing processes, facilitating continuous demetallization of activated carbon for supercapacitors and significantly reducing the purification process flow. Multiple baffles are installed within the first cylindrical cavity of the device, enhancing the contact between the material and the liquid under the impact pressure of the baffles, reducing the surface tension of the porous carbon, and particularly improving the degree of acid washing purification. The device produces a small batch of purified crude product, which facilitates thorough mixing of the material and the liquid. Furthermore, the device allows for continuous washing and filtration simultaneously, which not only facilitates the removal of soluble salts but also effectively reduces backmixing during the crude product purification process, decreasing the consumption of acidic solution and water. Compared to existing autoclave-type acid washing and water washing equipment, the device of this disclosure offers advantages such as high efficiency, small footprint, short process flow, convenient operation, and high production capacity.

[0024] In this disclosure, the filter membrane can be any material known to those skilled in the art. The filter membrane only needs to satisfy the requirement that it allows water molecules and soluble salt ions to pass through but not the activated carbon particles of the supercapacitor. For example, it can be a metal mesh filter membrane, a sintered mesh, a cellulose / polypropylene filter membrane, or a nylon filter membrane.

[0025] In this disclosure, the drive device can be coaxial with the housing 10 and located at the rear end of the device for continuous demetallization of activated carbon in supercapacitors. Here, "rear end" refers to the rear end of the device under normal operating conditions.

[0026] According to this disclosure, the central angles corresponding to the immersion zone, pickling zone, washing zone, and discharge zone can vary within a wide range. In one embodiment, the central angle corresponding to the immersion zone is 60-90°, the central angle corresponding to the pickling zone is 120-180°, the central angle corresponding to the washing zone is 60-90°, and the central angle corresponding to the discharge zone is greater than 0° and less than 120°.

[0027] In this disclosure, the central angles corresponding to the immersion zone, pickling zone, washing zone, and discharge zone refer to the central angles corresponding to the arcs of the outer shells of each zone. The central angles corresponding to the immersion zone, pickling zone, washing zone, and discharge zone can be determined based on the immersion, washing, and pickling times. Within the scope of the above embodiments, it is beneficial for the material to remain in the immersion zone, pickling zone, and washing zone for a sufficient time, ensuring the effectiveness of immersion, pickling, and washing.

[0028] In one embodiment, the aspect ratio of the outer shell 10 is (1-5):1, the aspect ratio of the filter membrane 11 is (2-6):1, and the aspect ratio of the inner shell 14 is (5-25):1; preferably, the ratio of the diameters of the outer shell 10, the filter membrane 11, and the inner shell 14 is (5-6):(4-5):1. Within the scope of the above embodiments, the spaces of the first cylindrical cavity and the second cylindrical cavity are suitable, which is more conducive to the complete contact between the material and the liquid in the impregnation zone, pickling zone, and washing zone, so that the crude activated carbon product for supercapacitors can be completely de-ashed and free of metallic impurities.

[0029] According to this disclosure, in the state of rotation or non-rotation, the first partition, the second partition, the third partition and the fourth partition each independently contact at least one baffle. Here, contact means that it is just enough to separate the immersion zone, the pickling zone, the washing zone and the discharge zone to prevent liquid from flowing between the zones, but contact does not affect the rotation of the baffle.

[0030] According to this disclosure, a plurality of baffles are disposed on the filter membrane and located within the first cylindrical cavity, specifically, the baffles are disposed within the first cylindrical cavity and one side of the baffle is connected to the filter membrane. In a preferred embodiment, the height of each baffle 9 is less than the distance between the outer housing 10 and the filter membrane 11. In this disclosure, the height of the baffle refers to the distance between one side connected to the filter membrane and its opposite side; the distance between the outer housing and the filter membrane refers to the length of the line segment between the inner side of the outer housing and the outer side of the filter membrane when a straight line passes perpendicularly through the outer housing and is perpendicularly connected to the axis, wherein the outer side of the filter membrane refers to the side facing the inner side of the outer housing.

[0031] In one embodiment, the distance between adjacent baffles 9 is less than the widths of the first separator 5, the second separator 6, the third separator 7, and the fourth separator 8. In this disclosure, the widths of the first, second, third, and fourth separators refer to the distance between two sides perpendicular to the outer casing. The distance between adjacent baffles 9 refers to the length of the arc between adjacent baffles. This disclosure does not specifically limit the number of baffles; for example, it can be 22, 24, or 26. When the widths of the first, second, third, and fourth separators satisfy the range of the above embodiment, it can be ensured that each baffle, whether rotated or not, can contact at least one baffle, thereby separating the immersion zone, pickling zone, washing zone, and discharge zone, preventing liquid exchange between the zones.

[0032] like Figure 1 As shown, the device further includes a Z-shaped scraper 4, which comprises an upper scraper, an intermediate receiving plate, and a lower guide plate. The upper scraper and the lower guide plate are respectively disposed at both ends of the intermediate receiving plate. The upper scraper is vertically connected to the intermediate receiving plate and is located in the first cylindrical cavity. The lower guide plate is movably connected to the intermediate receiving plate and is disposed at the discharge port on the outer shell 10 corresponding to the discharge area. In this disclosure, there is a space between each pair of adjacent baffles to accommodate the upper scraper of the Z-shaped scraper. The lower guide plate is movably connected to the intermediate receiving plate, allowing the upper scraper to swing within the space between a set of two adjacent baffles. As the baffles rotate, the scraper contacts the baffles and is bounced away, then returns to its original position and enters the space between the next set of two adjacent baffles, continuing the above movement. The material can leave the purification device under the action of the scraper and enter the subsequent process.

[0033] A second aspect of this disclosure provides a method for continuous demetallization of activated carbon in supercapacitors, the method comprising the following steps: S1. Turn on the drive device to drive the filter membrane 11 and the inner shell 14 to rotate together and drive each baffle 9 and each filtrate channel 12 to rotate. S2. The crude activated carbon product of the supercapacitor and the impregnation water are introduced into the impregnation zone from the first pure water inlet 1 for impregnation treatment to obtain the first material; S3. The acidic solution enters the pickling zone through the acidic solution inlet 2, and under the rotation drive of each baffle 9, the first material enters the pickling zone and comes into contact with the acidic solution for pickling treatment to obtain the second material. S4. The washing water enters the washing zone through the second pure water inlet 3, and the second material enters the washing zone and comes into contact with the washing water for washing under the rotation drive of each baffle 9. The resulting third material is discharged from the discharge port of the discharge zone under the rotation drive of each baffle 9.

[0034] In this disclosure, the pressure of the pure water or acidic solution at the first pure water inlet, the acidic solution inlet, and the second pure water inlet can be 0.5-5.0 MPa, and the temperature can be 80-90℃. The immersion water and washing water can be deionized water. The immersion water, acidic solution, and washing water enter the continuous demetallization device under a certain pressure, causing them to mix with the material after vigorous agitation. Furthermore, the continuous inflow of immersion water, acidic solution, and washing water ensures thorough rinsing of the material. Especially during the pickling process, the acidic solution fully contacts and reacts with the metallic impurities to generate soluble chlorides. The resulting waste liquid can be directly discharged through the filter membrane and the filtrate channel under pressure. The apparatus disclosed herein can be used to purify activated carbon for supercapacitors, enabling continuous purification with high purification efficiency. Furthermore, the purified activated carbon for supercapacitors meets the following requirements: ash content <0.2%, Fe, Ni, and Al <50 ppm, Co and Cu <20 ppm, Na and K <100 ppm, and Cl <20 ppm.

[0035] In this disclosure, the filter membrane and inner shell are driven to rotate together, which in turn drives each baffle and each filtrate channel to rotate, wherein the filter membrane, inner shell, each baffle, and each filtrate channel rotate at the same rotational speed. The rotational speed can vary within a wide range. In one embodiment, in step S1, the rotational speed is 0.1-3.0 r / h; in the above embodiment, the residence time of the material in the impregnation zone, acid washing zone, and water washing zone can be sufficiently guaranteed, so that the impregnation, acid washing, and water washing of the material are all more thorough, which is beneficial to the removal of ash and metal impurities from the crude activated carbon product of supercapacitors. In one embodiment, in step S2, the weight ratio of the crude activated carbon product of the supercapacitor to the impregnation water is 1:(3-8), and the impregnation time is 15-60 min; in step S3, the weight ratio of the first material to the acidic solution is 1:(3-5), and the acid washing time is 30-120 min; in step S4, the weight ratio of the second material to the washing water is 1:(4-8), and the washing time is 15-60 min.

[0036] In the above embodiments, the mass concentration of the acidic solution is 5-7%, and the acidic solution is selected from at least one of hydrochloric acid, sulfuric acid, and nitric acid.

[0037] In this disclosure, the method further includes: drying and grinding the discharged third material to obtain supercapacitor activated carbon; wherein the drying and grinding can be carried out using devices and methods conventionally used by those skilled in the art, and this disclosure does not specifically limit the conditions for drying and grinding, as long as they meet the standards for supercapacitor activated carbon in GBT37386-2019.

[0038] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0039] Example 1 like Figure 1 As shown, the continuous metal removal device of this embodiment includes an outer shell (length-to-diameter ratio of 3:1) 10, a filter membrane (length-to-diameter ratio of 5:1) 11, and an inner shell (length-to-diameter ratio of 15:1) arranged coaxially from the outside to the inside. The outer shell 10, the filter membrane 11, and the inner shell 14 are each independently cylindrical (the ratio of the diameters of the outer shell, the filter membrane, and the inner shell is 5:3:1). A first cylindrical cavity is formed between the outer shell 10 and the filter membrane 11. A first partition 5, a second partition 6, a third partition 7, and a fourth partition 8 are provided on the outer shell 10 to sequentially divide the first cylindrical cavity into impregnation zones. (Corresponding central angle is 90°), pickling zone (corresponding central angle is 120°), water washing zone (corresponding central angle is 90°) and discharge zone (corresponding central angle is 60°); a first pure water inlet 1 is provided on the outer shell 10 corresponding to the immersion zone and on the side near the first partition 5; an acidic solution inlet 2 is provided on the outer shell 10 corresponding to the pickling zone and on the side near the second partition 6; a second pure water inlet 3 is provided on the outer shell 10 corresponding to the water washing zone and on the side near the third partition 7; 22 baffles 9 are provided on the filter membrane 11 and located in the first cylindrical cavity; A second cylindrical cavity is formed between the filter membrane 11 and the inner shell 14. A plurality of filtrate channels 12 are provided in the second cylindrical cavity. The inlet of each filtrate channel 12 is connected to the filter membrane 11, and the outlet of each filtrate channel 12 is connected to the filtrate outlet 13 of the inner shell 14. The device also includes a drive unit for driving the filter membrane 11 and the inner housing 14 to rotate together and drive the rotation of each baffle 9 and each filtrate channel 12; in the state of rotation or non-rotation, the first separator 5, the second separator 6, the third separator 7 and the fourth separator 8 each independently contact at least one baffle 9.

[0040] The device also includes a Z-shaped scraper 4, which includes an upper scraper, an intermediate receiving plate, and a lower guide plate. The upper scraper and the lower guide plate are respectively disposed at both ends of the intermediate receiving plate. The upper scraper is vertically connected to the intermediate receiving plate and is located in the first cylindrical cavity. The lower guide plate is movably connected to the intermediate receiving plate and is disposed at the discharge port on the outer shell 10 corresponding to the discharge area.

[0041] The continuous demetallization device of Example 1 was used for the continuous demetallization of activated carbon in supercapacitors. The specific method is as follows: S1. Turn on the drive device to drive the filter membrane and the inner shell to rotate together and drive each baffle and each filtrate channel to rotate (speed is 0.2r / h). S2. The crude activated carbon product for supercapacitors and impregnation water (the mass ratio of crude activated carbon product for supercapacitors to water is 1:3) are introduced into the impregnation zone through the first pure water inlet and impregnated for 60 minutes to obtain the first material. S3. The acidic solution enters the pickling zone through the acidic solution inlet, and under the rotation drive of each baffle, the first material enters the pickling zone and comes into contact with the acidic solution (the weight ratio of 5% dilute hydrochloric acid to the first material is 3:1) for pickling treatment for 100 minutes to obtain the second material. S4. The washing water enters the washing zone through the second pure water inlet, and under the rotation drive of each baffle, the second material enters the washing zone and comes into contact with the washing water (the mass ratio of deionized water to the second material is 4:1) for 60 minutes of washing treatment. The resulting third material is discharged from the discharge port of the discharge zone under the rotation drive of each baffle. Then it enters the drying and grinding treatment to obtain supercapacitor activated carbon A.

[0042] The liquid pressure at the first pure water inlet, the acidic solution inlet, and the second pure water inlet is 0.6 MPa, and the temperature is 80℃.

[0043] Example 2 The same apparatus as in Example 1 is used, except that: the immersion zone (corresponding to a central angle of 90°), the pickling zone (corresponding to a central angle of 150°), the water washing zone (corresponding to a central angle of 70°), and the discharge zone (corresponding to a central angle of 50°).

[0044] The specific method is as follows: S1. Turn on the drive device to drive the filter membrane and the inner shell to rotate together and drive each baffle and each filtrate channel to rotate (speed is 0.3r / h). S2. The crude activated carbon product for supercapacitors and impregnation water (the mass ratio of crude activated carbon product for supercapacitors to water is 1:5) are introduced into the impregnation zone through the first pure water inlet and impregnated for 50 minutes to obtain the first material. S3. The acidic solution enters the pickling zone through the acidic solution inlet, and driven by the rotation of each baffle, the first material enters the pickling zone and comes into contact with the acidic solution (the mass ratio of 5% dilute hydrochloric acid to the first material is 5:1) for pickling treatment for 83 minutes to obtain the second material; S4. The washing water enters the washing zone through the second pure water inlet, and under the rotation drive of each baffle, the second material enters the washing zone and comes into contact with the washing water (the mass ratio of deionized water to the second material is 8:1) for 39 minutes of washing treatment. The resulting third material is discharged from the discharge port of the discharge zone under the rotation drive of each baffle. Then it enters the drying and grinding treatment, supercapacitor activated carbon B.

[0045] The liquid pressure at the first pure water inlet, the acidic solution inlet, and the second pure water inlet is 2.0 MPa, and the temperature is 80℃.

[0046] Example 3 The same apparatus as in Example 1 is used, except that: the immersion zone (corresponding to a central angle of 60°), the pickling zone (corresponding to a central angle of 150°), the washing zone (corresponding to a central angle of 90°), and the discharge zone (corresponding to a central angle of 60°).

[0047] The specific method is as follows: S1. Turn on the drive device to drive the filter membrane and the inner shell to rotate together and drive each baffle and each filtrate channel to rotate (speed is 0.4r / h). S2. The crude activated carbon product for supercapacitors and impregnation water (the mass ratio of crude activated carbon product for supercapacitors to water is 1:8) are introduced into the impregnation zone through the first pure water inlet and impregnated for 21 minutes to obtain the first material. S3. The acidic solution enters the pickling zone through the acidic solution inlet, and driven by the rotation of each baffle, the first material enters the pickling zone and comes into contact with the acidic solution (the mass ratio of 5% dilute hydrochloric acid to the first material is 5:1) for pickling treatment for 62.5 minutes to obtain the second material; S4. The washing water enters the washing zone through the second pure water inlet, and under the rotation drive of each baffle, the second material enters the washing zone and comes into contact with the washing water (the mass ratio of deionized water to the second material is 6:1) for washing treatment for 37.5 minutes. The resulting third material is discharged from the discharge port of the discharge zone under the rotation drive of each baffle. Then it enters the drying and grinding process, and the supercapacitor activated carbon C.

[0048] The liquid pressure at the first pure water inlet, the acidic solution inlet, and the second pure water inlet is 3.0 MPa, and the temperature is 90℃.

[0049] Test Example 1 The activated carbons A, B, and C for supercapacitors prepared in Examples 1-3 were tested for ash content, Fe, Ni, Al, Co, Cu, Na, K, and Cl. Volatile matter was determined according to YB / T 5189, and trace metal elements were determined according to GB / T 24533. The results are recorded in Table 1.

[0050] Table 1

[0051] As shown in Table 1, the purified activated carbon for supercapacitors meets the following requirements: ash content <0.2%, Fe, Ni, and Al <50 ppm, Co and Cu <20 ppm, Na and K <100 ppm, and Cl <20 ppm. The device disclosed herein enables continuous purification and features high efficiency, small footprint, short process flow, convenient operation, and high production capacity.

[0052] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0053] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0054] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A device for continuous demetallization of activated carbon in supercapacitors, characterized in that, The device includes an outer shell (10) arranged axially in the horizontal direction, and a filter membrane (11) and an inner shell (14) arranged in sequence from the outer shell (10) and coaxial with the outer shell (10), wherein the outer shell (10), the filter membrane (11) and the inner shell (14) are each independently cylindrical; A first cylindrical cavity is formed between the outer shell (10) and the filter membrane (11); a first partition (5), a second partition (6), a third partition (7) and a fourth partition (8) are provided on the outer shell (10) to divide the first cylindrical cavity into an immersion zone, an acid pickling zone, a water washing zone and a discharge zone in sequence; a first pure water inlet (1) is provided on the outer shell (10) corresponding to the immersion zone and on the side near the first partition (5); an acidic solution inlet (2) is provided on the outer shell (10) corresponding to the acid pickling zone and on the side near the second partition (6); a second pure water inlet (3) is provided on the outer shell (10) corresponding to the water washing zone and on the side near the third partition (7); a plurality of baffles (9) are provided on the filter membrane (11) and located in the first cylindrical cavity. A second cylindrical cavity is formed between the filter membrane (11) and the inner shell (14). A plurality of filtrate channels (12) are provided in the second cylindrical cavity. The inlet of each filtrate channel (12) is connected to the filter membrane (11), and the outlet of each filtrate channel (12) is connected to the filtrate outlet (13) of the inner shell (14). The device further includes a driving device for driving the filter membrane (11) and the inner shell (14) to rotate together and drive the rotation of each baffle (9) and each filtrate channel (12); in the state of rotation or non-rotation, the first separator (5), the second separator (6), the third separator (7) and the fourth separator (8) each independently contact at least one baffle (9).

2. The apparatus according to claim 1, wherein, The central angle corresponding to the immersion zone is 60-90°, the central angle corresponding to the pickling zone is 120-180°, the central angle corresponding to the washing zone is 60-90°, and the central angle corresponding to the discharge zone is greater than 0° and less than 120°.

3. The apparatus according to claim 1, wherein, The aspect ratio of the outer shell (10) is (1-5):1, the aspect ratio of the filter membrane (11) is (2-6):1, and the aspect ratio of the inner shell (14) is (5-25):

1. Preferably, the ratio of the diameters of the outer shell (10), the filter membrane (11), and the inner shell (14) is (5-6):(4-5):

1.

4. The apparatus according to claim 1, wherein, The height of each baffle (9) is less than the distance between the outer housing (10) and the filter membrane (11).

5. The apparatus according to claim 4, wherein, The distance between adjacent baffles (9) is less than the width of each of the first separator (5), the second separator (6), the third separator (7) and the fourth separator (8).

6. The apparatus according to claim 1, wherein, The device also includes a Z-shaped scraper (4), which includes an upper scraper, an intermediate receiving plate and a lower draining plate, with the upper scraper and the lower draining plate respectively disposed at both ends of the intermediate receiving plate; The upper scraper is vertically connected to the intermediate receiving plate and is located in the first cylindrical cavity; The lower guide plate is movably connected to the intermediate receiving plate and is located at the discharge port on the outer shell (10) corresponding to the discharge area.

7. A method for continuous demetallization of activated carbon in supercapacitors, characterized in that, The method includes the following steps: S1. Turn on the drive device to drive the filter membrane (11) and the inner shell (14) to rotate together and drive each baffle (9) and each filtrate channel (12) to rotate; S2. The crude activated carbon product of the supercapacitor and the impregnation water are introduced into the impregnation zone through the first pure water inlet (1) for impregnation treatment to obtain the first material; S3. The acidic solution enters the pickling zone through the acidic solution inlet (2), and under the rotation drive of each baffle (9), the first material enters the pickling zone and comes into contact with the acidic solution for pickling treatment to obtain the second material. S4. The washing water enters the washing zone through the second pure water inlet (3), and under the rotation drive of each baffle (9), the second material enters the washing zone and comes into contact with the washing water for washing treatment. The resulting third material is discharged from the discharge port of the discharge zone under the rotation drive of each baffle (9).

8. The method according to claim 7, wherein, In step S1, the rotational speed is 0.1-3.0 r / h; In step S2, the weight ratio of the crude activated carbon product for the supercapacitor to the impregnation water is 1:(3-8), and the impregnation time is 15-60 min. In step S3, the weight ratio of the first material to the acidic solution is 1:(3-5), and the pickling time is 30-120 min. In step S4, the weight ratio of the second material to the washing water is 1:(4-8), and the washing time is 15-60 min.

9. The method according to claim 8, wherein, The acidic solution has a mass concentration of 5-7%, and the acidic solution is selected from at least one of hydrochloric acid, sulfuric acid, and nitric acid.

10. The method according to claim 7, wherein, The method further includes: drying and grinding the discharged third material to obtain supercapacitor activated carbon.

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