Slurry de-magnetizing device

Abstract

The present application relates to the field of magnetic equipment, specifically provides a kind of slurry magnetic device, to solve the problem of poor magnetic effect of slurry magnetic equipment in prior art, there is the risk of nickel precipitation.For this purpose, the magnetic device of the present application includes accommodating body and multistage magnetic unit, the accommodating cavity is provided in the accommodating body, the accommodating cavity is used for the slurry to pass;The multistage magnetic unit is sequentially arranged in the accommodating cavity along the direction of the slurry passing, at least one level of the multistage magnetic unit includes pulse electromagnetic assembly, by the above technical solution, the magnetic foreign matter in slurry can be attracted and removed by high-intensity pulsed magnetic field, and the risk of nickel precipitation in slurry caused by persistent high-intensity magnetic field can be avoided.

Description

Technical Field

[0001] This invention relates to the field of demagnetizing equipment, and specifically provides a slurry demagnetizing device. Background Technology

[0002] Lithium-ion batteries for automobiles, as a type of high-energy-density electrochemical battery unit, can be used in various consumer products and vehicles such as hybrid electric vehicles (HEVs) and pure electric vehicles (EVs). A typical power battery usually includes the following components: positive and negative electrodes that can insert and extract lithium ions, a separator containing electronic insulation and ion transport functions between the positive and negative electrodes, an electrolyte that conducts lithium ions, and accessories such as current collectors, tabs, and casing.

[0003] Currently, thermal runaway in lithium-ion batteries is a major safety concern, primarily caused by magnetic foreign objects piercing the separator within the cell. This piercing can occur in two ways: first, the foreign object is too close to the outer edge of the positive and negative electrode coatings. During hot pressing, the compression of the electrode foils, coatings, and separator causes the foreign object to pierce the separator, resulting in a short circuit. Second, the high electrode potential of the positive electrode causes the magnetic foreign object to oxidize and dissolve into ions. When these dissolved ions migrate to the surface of the negative electrode under the influence of an electric field, the extremely low electrode potential reduces them to a metallic state, forming dendrites. When these dendrites grow large enough to pierce the separator, a short circuit occurs, leading to self-discharge and ultimately thermal runaway.

[0004] As can be seen from the above description, the removal of magnetic foreign matter in the manufacturing process of power batteries is a very important step. Therefore, in the current manufacturing of power batteries, after the positive and negative electrode materials and conductive agents, binders, solvents and other materials form a slurry, the slurry is generally passed through a permanent magnet demagnetizing device to remove magnetic foreign matter before being coated onto the surface of the positive and negative electrode foils to form electrodes.

[0005] Existing demagnetization technology uses permanent magnet rods for demagnetization. These demagnetization devices generally use a combination of one or more permanent magnet rods. The rods are typically cylindrical, with a surface magnetic field strength of 2000-20000 Gauss. The diameter of the rods is usually about 1.5-3.0 cm. When the slurry passes through this demagnetization device formed by a combination of single or multiple rods, the magnetic metal foreign particles contained in the slurry are adsorbed onto the surface of the rods, thereby achieving the purpose of removing magnetic foreign particles.

[0006] However, this demagnetization method has two major drawbacks. First, since the permanent magnet rod only contacts the surface of the flowing slurry, when the distance between the permanent magnet rod and the slurry flow channel wall is too large, only magnetic foreign objects close to the rod can be attracted, while magnetic foreign objects farther away or with weaker magnetism cannot be well attracted to the rod. When the distance is too small, it may affect the flow of the slurry. Second, since the permanent magnet is a continuous magnetic field, when the magnetic field strength is too high, the continuous strong magnetic field will cause the risk of nickel deposition in the material, while when the magnetic field strength is too low, the demagnetization effect is very poor. Therefore, in actual battery manufacturing, the demagnetization effect of permanent magnets is limited and difficult to control. Poor slurry demagnetization will directly affect the subsequent application of the slurry, such as the quality of power batteries.

[0007] Accordingly, there is a need in the field for a new slurry demagnetization device to solve the above problems. Summary of the Invention

[0008] This invention aims to solve the aforementioned technical problems, namely, the poor demagnetization effect and the risk of nickel precipitation in existing slurry demagnetization equipment. To this end, this invention provides a slurry demagnetization device, which includes:

[0009] A receiving body, wherein a receiving cavity is provided within the receiving body for the passage of the slurry;

[0010] A multi-stage demagnetizing unit is provided, wherein the multi-stage demagnetizing units are sequentially arranged in the receiving cavity along the direction in which the slurry passes, and the multi-stage demagnetizing unit has at least one magnetic attraction unit including a pulse electromagnetic component.

[0011] In the specific embodiments of the above-described slurry demagnetizing device, the multi-stage demagnetizing unit has at least one magnetic attraction unit including a permanent magnet component; and / or

[0012] The multi-stage demagnetizing unit has at least one magnetic attraction unit, which includes the pulse electromagnetic component and the permanent magnet component.

[0013] In the specific embodiment of the above-mentioned slurry demagnetization device, the demagnetization device further includes a stirring unit, which is disposed between the multi-stage demagnetization units.

[0014] In the specific embodiment of the above-mentioned slurry demagnetization device, the demagnetization device further includes a buffer dispersion plate, the receiving body is provided with a slurry inlet and a slurry outlet, and the buffer dispersion plate is disposed at the slurry inlet and the slurry outlet.

[0015] In the specific embodiment of the above-mentioned slurry demagnetization device, the demagnetization device further includes a pulse magnetic field controller. The pulse electromagnetic component includes a housing, a soft magnet and an electromagnetic coil. The housing is connected to the inner wall of the receiving body. A plurality of electromagnetic coils are spaced apart on the housing. The soft magnet is disposed on the housing and passes through the electromagnetic coil. The electromagnetic coil is electrically connected to the pulse magnetic field controller.

[0016] In the specific embodiment of the above-mentioned slurry demagnetization device, the containing body is a box, the stirring unit includes a driving component and a stirring blade, the driving component is disposed on the outside of the containing body, and the stirring blade is connected to the driving end of the driving component that extends into the containing body.

[0017] In the specific embodiment of the above-mentioned slurry demagnetization device, the stirring blade includes a plurality of propeller blades, the driving assembly includes a drive motor and a reducer adapted to the drive motor, and the ends of the plurality of propeller blades are connected to the output end of the reducer that extends into the receiving body.

[0018] In the specific embodiment of the above-mentioned slurry demagnetization device, the buffer dispersion plate is provided with a plurality of dispersion holes, and the height of the slurry outlet is higher than the height of the slurry inlet.

[0019] In the specific embodiment of the above-mentioned slurry demagnetization device, a cleaning and sewage discharge outlet is provided at the bottom of the receiving body.

[0020] In the specific embodiment of the above-mentioned slurry demagnetizing device, the demagnetizing device further includes a cover plate, which is disposed on the receiving body, and the wiring terminal of the pulse magnetic attraction component is located inside the cover plate.

[0021] By adopting the above technical solution, the present invention can reduce the risk of nickel precipitation in the slurry during demagnetization while removing magnetic foreign matter from the slurry more efficiently and thoroughly. Specifically, the slurry is demagnetized by a conveying method in which it flows through a receiving body with a receiving cavity. The receiving body can be selected with a suitable shape according to the application scenario. The demagnetization method involves installing a multi-stage demagnetization unit in the receiving cavity. At least one stage of the demagnetization unit is a pulsed electromagnetic component. The pulsed electromagnetic component generates a high-intensity pulsed magnetic field, which can better attract magnetic foreign matter in the slurry. Even magnetic particles with low magnetic properties can be adsorbed and removed. The remaining parts of the multi-stage demagnetization unit can use other demagnetization components to achieve a continuous magnetic field with a low magnetic field strength, attracting and removing the remaining magnetic foreign matter in the slurry. The high-intensity pulsed magnetic field avoids the risk of nickel precipitation in the slurry due to magnetic attraction, improves the removal effect of magnetic foreign matter, thereby improving the quality of the slurry and avoiding safety hazards in the battery caused by its use as a raw material for power battery production. Attached Figure Description

[0022] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0023] Figure 1 This is a schematic diagram of the structure of a demagnetizing device in the prior art;

[0024] Figure 2 This is a schematic diagram of the internal structure of the demagnetizing device in this invention. Figure 1 The diagram shows the positional relationships of the multi-stage demagnetizing units;

[0025] Figure 3 This is a schematic diagram of the internal structure of the demagnetizing device in this invention. Figure 2 The structure of the buffer dispersion plate and the stirring unit is shown therein;

[0026] Figure 4 This is a schematic diagram of the pulse electromagnetic component in this invention;

[0027] Figure 5 This is a schematic diagram of the permanent magnet component in this invention.

[0028] In the diagram: 1. Container body, 2. Container cavity, 3. Multi-stage demagnetizing unit, 4. Pulse electromagnetic component, 5. Permanent magnet component, 6. Stirring unit, 7. Buffer dispersion plate, 8. Slurry inlet, 9. Slurry outlet, 10. Pulse magnetic field controller, 11. Shell, 12. Soft magnet, 13. Electromagnetic coil, 14. Drive component, 15. Stirring blade, 16. Propeller blade, 17. Drive motor, 18. Reducer, 19. Dispersion hole, 20. Cleaning and sewage outlet, 21. Cover plate, 22. Demagnetizing pipe, 23. Feed inlet, 24. Discharge outlet, 25. Permanent magnet demagnetizing unit, 26. Permanent magnet. Detailed Implementation

[0029] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings and in conjunction with a demagnetizing device for power battery slurry. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. For example, as... Tube The specification describes the invention in conjunction with a demagnetizing device for power battery slurry; however, this is not limiting, and those skilled in the art can apply the invention to other demagnetizing devices as needed.

[0030] It should be noted that in the description of this invention, terms such as "upper," "lower," "left," "right," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the relevant devices or elements must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, ordinal numbers such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] like Figure 1 The diagram shows a demagnetizing device for power battery slurry in the prior art. Specifically, the demagnetizing device in the prior art is a demagnetizing pipe 2 with an inlet 23 and an outlet 24. The shape of the demagnetizing pipe and the number of permanent magnet demagnetizing units can be selected according to requirements. In the illustrated embodiment, U-shaped pipes are connected in series, and permanent magnet demagnetizing units 25 are installed in two branch pipes inside the U-shaped pipes. The slurry is introduced from the inlet 23 and flows in the demagnetizing pipe 22. The slurry is split into two branch pipes of the two U-shaped pipes and contacts the permanent magnet demagnetizing units 25, attracting and removing magnetic foreign objects in the slurry. However, in this demagnetizing device, the contact area between the slurry and the permanent magnet demagnetizing units 25, the distance between the magnetic foreign objects and the permanent magnet demagnetizing units 25, and the contact time between the slurry and the permanent magnet demagnetizing units 25 during the flow are all limited. Therefore, the demagnetizing effect is poor. If the magnetic field strength is increased, a continuous high-intensity magnetic field will cause nickel precipitation in the slurry, affecting the quality of the slurry.

[0033] like Figures 2 to 3 As shown, the present invention proposes a slurry demagnetizing device, the demagnetizing device comprising:

[0034] The container body 1 has a container cavity 2 inside, which is used for the slurry to pass through;

[0035] A multi-stage demagnetizing unit 3 is arranged sequentially in the receiving cavity 2 along the direction in which the slurry passes. The multi-stage demagnetizing unit 3 has at least one magnetic attraction unit including a pulse electromagnetic component 4.

[0036] In this embodiment, a multi-stage demagnetizing unit 3 is installed in the receiving cavity 2 within the receiving body 1. At least one stage of the multi-stage demagnetizing unit 3 is a pulsed electromagnetic component 4, thereby forming a pulsed magnetic field with a magnetic field strength of 10,000-20,000 Gs and a pulse frequency of 100-1,000 Hz. The high-intensity pulsed magnetic field can adsorb magnetic foreign matter in the slurry. Even magnetic foreign matter with low magnetic properties can be attracted and removed. Since it is a pulsed magnetic field, there are intermittent periods, which can effectively avoid nickel precipitation in the slurry caused by a continuous high-intensity magnetic field.

[0037] Based on the above embodiments, see [link / reference] Figure 2 and Figure 3 In this embodiment, the receiving body 1 is in the shape of a box. The box has a slurry inlet 8 and a slurry outlet 9. The slurry enters from the slurry inlet 8 and flows into the receiving cavity 2 to the slurry outlet 9. After the slurry enters the receiving body 1, a multi-level magnetic suction unit is set along its flow direction to remove magnetic foreign objects in the slurry.

[0038] In this embodiment, the slurry inlet 8 and slurry outlet 9 are preferably opened on opposite sides, so that the slurry flows directly and the path distance is larger. A multi-stage demagnetizing unit 3 is installed between the slurry inlet 8 and slurry outlet 9. The multi-stage demagnetizing unit 3 should cover the cross-sectional area of ​​the slurry flowing in the receiving body 1, allowing the slurry to pass through the gaps between the demagnetizing units. The demagnetizing unit can be a permanent magnet demagnetizing unit in the prior art or a continuously energized electromagnetic component to form a continuous magnetic field with a low magnetic field strength. A pulse electromagnetic component 4 must be installed in the multi-stage demagnetizing unit 3 to form a high-intensity pulse magnetic field. In this embodiment, the demagnetizing unit is installed close to the slurry inlet 8 and slurry outlet 9. The demagnetizing units are arranged in a row and arrayed, with gaps between the demagnetizing units for the slurry to pass through. The demagnetizing units of the slurry inlet 8 and slurry outlet 9 are both permanent magnet components 5 and pulse electromagnetic components 4 arranged in a row. The gaps between the permanent magnet components 5 and the gaps between the pulse electromagnetic components 4 are staggered, which helps to improve the contact between the slurry and the demagnetizing unit.

[0039] It should be noted that in the above embodiments, the receiving body 1 can be other forms suitable for slurry passage, such as tubular or cylindrical shapes; the positions of the slurry inlet 8 and slurry outlet 9 on the receiving body 1 can also be flexibly set according to the installation requirements of the demagnetizing device.

[0040] Based on the above embodiments, see [link to relevant documentation]. Figure 4 and Figure 5The pulse electromagnetic component 4 and the permanent magnet component 5 are combined to form a multi-stage demagnetizing unit 3. The arrangement of the pulse electromagnetic component 4 and the permanent magnet component 5 can be flexibly set according to the requirements. They can be arranged in a straight matrix or in other matrix shapes, as long as the slurry can be adsorbed and demagnetized within the gap between the demagnetizing units.

[0041] Figure 4 and Figure 5 This is a schematic diagram of the structure of the pulse electromagnetic component 4 and the permanent magnet component 5 in this invention. The permanent magnet component 5 consists of a permanent magnet 26 installed inside a housing 11 via a covering layer. The permanent magnet 26 is mainly composed of magnetic materials such as magnetite (Fe3O4), maghematite (γ-Fe2O3), neodymium iron boron magnets, samarium cobalt magnets, AlNiCo magnets, iron-chromium-cobalt magnets, and ferrite magnets. The covering layer can be composed of wear-resistant, organic solvent-resistant, and corrosion-resistant materials such as stainless steel, epoxy resin, polytetrafluoroethylene (commonly known as Teflon), resin, and ceramics. The pulse electromagnetic component 4 encloses the soft magnet 12 and the electromagnetic coil 13 within the housing 11. Both ends are connected to the inner wall of the receiving cavity 2. Soft magnets 12 are installed on the housing 11. Electromagnetic coils 13 are also installed at intervals along the length of the housing 11. Soft magnets 12 pass through electromagnetic coils 13. Electromagnetic coils 13 charge and demagnetize soft magnets 12 through a pulse electromagnetic controller. Soft magnets 12 can be charged and demagnetized in real time. Electromagnetic coils 13 and soft magnets 12 are covered inside the housing 11 by a coating layer. The coating layer can be composed of stainless steel, epoxy resin, polytetrafluoroethylene (commonly known as Teflon), resin, ceramics, etc. The specific shape of the housing 11 can be flexibly selected according to the actual application scenario and can be round, square, elliptical or trapezoidal.

[0042] Based on the above embodiments, by installing a stirring unit 6 inside the receiving body 1, the slurry can be disturbed during the flow process, thereby allowing the slurry to fully contact the demagnetizing unit. Those skilled in the art can select a suitable structural device based on the receiving body 1, and can adopt rotary stirring, reciprocating stirring, or vibration stirring.

[0043] Based on the above embodiments, refer to Figure 2 and Figure 3The container body 1 adopts a box-type structure. Magnetic suction units are set at both the slurry inlet 8 and the slurry outlet 9. A rotary stirring device is installed between the two magnetic suction units. Specifically, a drive motor 17 and a reducer 18 adapted to it are installed on the container body 1. The output end of the reducer 18 extends into the receiving cavity 2 inside the container body 1. A stirring blade 15 is installed on the output end of the reducer 18. The stirring blade 15 is preferably a propeller blade 16. The propeller blade 16 stirs the slurry to form a vortex. In this embodiment, the straight-flowing slurry is driven by the propeller blade 16 to form a vortex, which can contact the demagnetizing unit more evenly, increase the contact area, and also make the straight-flowing slurry mix evenly from left to right. The propeller blade 16 consists of several single spiral blades connected by a connecting rod. Several spiral blades are connected by bending to form a hollow propeller blade 16, which facilitates the passage of slurry and also achieves the purpose of stirring to form a vortex.

[0044] Based on the above embodiments, please continue to refer to Figure 2 and Figure 3 A buffer dispersion plate 7 is installed at the slurry inlet 8 and the slurry outlet 9. The buffer dispersion plate 7 has dispersion holes 19 that allow the slurry to pass through, which can reduce the impact force of the slurry flow and improve the dispersion degree of the slurry through the dispersion holes 19. In addition, the height of the slurry outlet 9 is higher than the height of the slurry inlet 8, which can allow the slurry to maintain sufficient adsorption and demagnetization in the container body 1. After demagnetization, the internal impurities are cleaned and the cleaning agent and waste are discharged from the cleaning and sewage outlet 20 located at the bottom of the container body 1.

[0045] Installing a cover plate 21 on the housing 1 protects the wiring terminals of the pulse magnetic system components, improves safety protection, avoids aging and corrosion, and extends the service life of the equipment.

[0046] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A slurry demagnetizing device, characterized in that, The demagnetizing device includes: The container body (1) has a container cavity (2) inside, which is used for the passage of the slurry; A multi-stage demagnetizing unit (3) is arranged sequentially in the receiving cavity (2) along the direction in which the slurry passes. The multi-stage demagnetizing unit (3) has at least one magnetic attraction unit including a pulse electromagnetic component (4) and a permanent magnet component (5). The gaps between the pulse electromagnetic components (4) and the gaps between the permanent magnet components (5) are staggered. The pulsed electromagnetic component (4) forms a high-intensity pulsed magnetic field, and the magnetic field strength formed by the permanent magnet component (5) is lower than that of the pulsed magnetic field, in order to prevent nickel deposition in the slurry; The demagnetizing device also includes a stirring unit (6), which is disposed between the multi-stage demagnetizing units (3).

2. The slurry demagnetizing device according to claim 1, characterized in that, The demagnetizing device also includes a buffer dispersion plate (7), and the receiving body (1) is provided with a slurry inlet (8) and a slurry outlet (9). The buffer dispersion plate (7) is provided at the slurry inlet (8) and the slurry outlet (9).

3. The slurry demagnetizing device according to claim 1, characterized in that, The demagnetizing device further includes a pulse magnetic field controller (10). The pulse electromagnetic component (4) includes a housing (11), a soft magnet (12), and an electromagnetic coil (13). The housing (11) is connected to the inner wall of the receiving body (1). A plurality of electromagnetic coils (13) are spaced apart on the housing (11). The soft magnet (12) is disposed on the housing (11) and passes through the electromagnetic coil (13). The electromagnetic coil (13) is electrically connected to the pulse magnetic field controller (10).

4. The slurry demagnetizing device according to claim 1, characterized in that, The container body (1) is a box, and the stirring unit (6) includes a driving assembly (14) and a stirring blade (15). The driving assembly (14) is located on the outside of the container body (1), and the stirring blade (15) is connected to the driving end of the driving assembly (14) extending into the container body (1).

5. The slurry demagnetizing device according to claim 4, characterized in that, The stirring blade (15) includes a plurality of propeller blades (16), and the drive assembly (14) includes a drive motor (17) and a reducer (18) adapted to the drive motor (17). The ends of the plurality of propeller blades (16) are connected to the output end of the reducer (18) that extends into the receiving body (1).

6. The slurry demagnetizing device according to claim 2, characterized in that, The buffer dispersion plate (7) is provided with a plurality of dispersion holes (19), and the height of the slurry outlet (9) is higher than the height of the slurry inlet (8).

7. The slurry demagnetizing device according to any one of claims 1 to 6, characterized in that, The bottom of the container (1) is provided with a cleaning and sewage outlet (20).

8. The slurry demagnetizing device according to claim 3, characterized in that, The demagnetizing device also includes a cover plate (21), which is disposed on the receiving body (1), and the wiring terminal of the pulse electromagnetic component (4) is located inside the cover plate (21).

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