Detection and screening equipment for magnetic particles of battery electrode material

Abstract

The utility model belongs to the technical field of battery manufacturing, and discloses magnetic particle detecting and screening equipment for a battery electrode material. The battery electrode material magnetic particle detecting and screening equipment comprises a cylinder, an electromagnetic rod and a controller, a containing cavity of the cylinder is used for containing a to-be-screened material, and the center axis of the end wall of one axial end of the cylinder is connected with the output end of a driving mechanism so that the cylinder can rotate around the axis of the cylinder; the electromagnetic rod is axially inserted in the central axis of the end wall of the other axial end of the barrel in a sealed manner, and a heating assembly is arranged on the outer wall of the electromagnetic rod; the controller is connected to the electromagnetic rod and the heating assembly, and the controller can control the magnetic field intensity of the electromagnetic rod and the temperature of the heating assembly. The magnetic particle detection and screening equipment for the battery electrode material can improve the collection efficiency and collection effect of magnetic particles in the electrode material, reduces adsorption of the particles of the electrode material, and ensures that the subsequent magnetic particle detection result is more accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of battery manufacturing, in particular to a device for detecting and screening magnetic particles of battery electrode materials. Background Art

[0002] Magnetic foreign matter in the battery electrode material will slowly precipitate from the positive electrode during the battery cycle. Since the anode does not have the ability to de-embed the magnetic foreign matter, the magnetic foreign matter will precipitate on the surface of the negative electrode and may grow as dendrites, creating the risk of piercing the diaphragm, which can lead to severe self-discharge of the battery at the very least, and even worse, it may cause thermal runaway and cause serious safety accidents.

[0003] The current standards for determining the magnetic foreign matter content and residual alkali content of lithium-ion battery positive electrode materials and the detection standards for the magnetic foreign matter content in lithium-ion battery electrode materials are not applicable to lithium iron phosphate materials. This is because the iron element in lithium iron phosphate is a strong magnetic element, which causes lithium iron phosphate materials to usually exhibit paramagnetism during magnetic separation. After magnetic separation, the lithium iron phosphate material and the magnetic foreign matter cannot be completely separated, resulting in the iron content in the ICP (Inductively Coupled Plasma) test being much higher than the magnetic foreign matter content, which seriously affects the test accuracy of the magnetic foreign matter content.

[0004] The current mainstream sodium-ion battery electrode materials all contain ferromagnetic elements such as iron and nickel. Since ferromagnetic elements have unpaired electrons in their electron layers, they will exhibit a net magnetic moment in the absence of an external magnetic field. Under the action of an external magnetic field, these dipoles tend to point in the direction of the external magnetic field, exhibiting paramagnetism, which causes some materials to be adsorbed on the magnetic rod, making it difficult to separate them from real magnetic foreign matter.

[0005] There are two methods for testing and adsorbing magnetic foreign matter in the prior art: one is the JMS test, which is to put a permanent magnetic bar in a nylon drum, collect magnetic foreign matter through the rolling of the material and the adsorption of the permanent magnetic bar, and then perform magnetic particle detection; the other is the MI test, which is to put a permanent magnetic bar in a plastic drum, collect the material through the rolling of the material and the adsorption of the permanent magnetic bar, then wash the collected material by ultrasound, boil it with acid to make it constant, and test the content of impurities such as iron, chromium, nickel, copper, and zinc by ICP. However, no matter how the above two methods are ultrasonically cleaned, there will be residual sodium ion electrode materials, which will affect the accuracy of the final test results.

[0006] Therefore, there is an urgent need to provide a new type of battery electrode material magnetic particle detection and screening equipment to solve the above-mentioned technical problems existing in the prior art. Utility Model Content

[0007] The purpose of the utility model is to provide a battery electrode material magnetic particle detection and screening device, which can improve the collection efficiency and collection effect of magnetic particles in the electrode material, and reduce the adsorption of electrode material particles, so as to ensure that the subsequent magnetic particle detection results are more accurate.

[0008] To achieve this purpose, the utility model adopts the following technical solutions:

[0009] The battery electrode material magnetic particle detection and screening equipment comprises a cylinder, an electromagnetic rod and a controller. The accommodating cavity of the cylinder is used to accommodate the material to be screened. The central axis of the end wall at one axial end of the cylinder is connected to the output end of a driving mechanism so that the cylinder can rotate around its own axis. The electromagnetic rod is axially sealed and inserted at the central axis of the end wall at the other axial end of the cylinder. A heating assembly is arranged on the outer wall of the electromagnetic rod. The controller is connected to the electromagnetic rod and the heating assembly. The controller can control the magnetic field strength of the electromagnetic rod and the temperature of the heating assembly.

[0010] Optionally, the cylinder body comprises a cylinder cover and a cylinder body, the cylinder body is connected to the output end of the driving mechanism, the cylinder cover is penetrated by the electromagnetic rod, and the cylinder cover is detachably connected to the cylinder body.

[0011] Optionally, the cylinder cover is flange-connected to the cylinder body.

[0012] Optionally, a sealing ring is provided at the flange connection between the cylinder cover and the cylinder body.

[0013] Optionally, a dynamic sealing ring is fixedly connected to the outer wall of the axial end wall of the cylinder cover, and the inner wall of the dynamic sealing ring is sealed and connected to the electromagnetic rod and can rotate relatively.

[0014] Optionally, the electromagnetic rod is fixedly connected with a static sealing ring, and the static sealing ring is sealed and connected to the inner wall of the axial end wall of the cylinder cover and can slide relative to it.

[0015] Optionally, the outer wall of the heating component is also covered with a non-magnetic outer jacket.

[0016] Optionally, the non-magnetic outer sleeve is made of ceramic or plastic.

[0017] Optionally, a plurality of stirring parts are provided on the circumferential inner wall of the cylinder, and the stirring parts are extended toward the central axis of the cylinder.

[0018] Optionally, the heating assembly includes a thermocouple, a heating element and a temperature control system, the thermocouple and the temperature control system are both communicatively connected to the controller, and the heating element is electrically connected to the temperature control system.

[0019] Beneficial effects:

[0020] The battery electrode material magnetic particle detection and screening device in the utility model accommodates the material to be screened in a cylinder, and the axis of the axial end wall of the cylinder is connected to the output end of the driving mechanism, so that the driven mechanism is driven to rotate around its own axis, driving the material to be screened to roll in the accommodating cavity, fully contacting the electromagnetic rod set on the other end wall, and adsorbing as many magnetic particles in the material to be screened as possible; and the outer wall of the electromagnetic rod is also provided with a heating component, and the controller is connected to the electromagnetic rod and the heating component, so as to control the magnetic field strength of the electromagnetic rod and the temperature of the heating component, and according to the different characteristics of the Curie temperature of different materials, the foreign matter of the magnetic particles in the material to be screened is collected at different temperatures, and the electrode material particles in the material to be screened are not adsorbed. The battery electrode material magnetic particle detection and screening device can improve the collection efficiency and collection effect of the magnetic particle foreign matter in the positive electrode material, and reduce the adsorption of the positive electrode material particles, so as to ensure that the subsequent magnetic particle detection results are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a device for detecting and screening magnetic particles of battery electrode materials provided by a specific embodiment of the utility model;

[0022] Figure 2 This is the Curie temperature test curve of the sodium ion battery electrode material in Example 1 provided in the specific implementation manner of the utility model.

[0023] In the figure:

[0024] 100, cylinder; 101, driving mechanism; 110, cylinder body; 111, stirring part; 120, cylinder cover; 121, dynamic sealing ring; 122, static sealing ring; 130, connecting flange; 131, sealing ring;

[0025] 210, electromagnetic rod; 220, heating component; 230, non-magnetic jacket;

[0026] 300. Controller. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0028] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0031] Please refer to Figure 1 In this embodiment, the battery electrode material magnetic particle detection and screening device includes a cylinder 100, an electromagnetic rod 210 and a controller 300. The accommodating cavity of the cylinder 100 is used to accommodate the material to be screened. The output end of the driving mechanism 101 is connected to the central axis of the end wall at one axial end of the cylinder 100 to enable the cylinder 100 to rotate around its own axis; the electromagnetic rod 210 is axially sealed and inserted at the central axis of the end wall at the other axial end of the cylinder 100, and a heating component 220 is arranged on the outer wall of the electromagnetic rod 210; the controller 300 is connected to the electromagnetic rod 210 and the heating component 220, and the controller 300 can control the magnetic field strength of the electromagnetic rod 210 and the temperature of the heating component 220.

[0032] The battery electrode material magnetic particle detection and screening device in this embodiment accommodates the material to be screened in the cylinder 100, and the axis of the axial end wall of the cylinder 100 is connected to the output end of the driving mechanism 101, so that the driving mechanism 101 is driven to rotate around its own axis, driving the material to be screened to roll in the containing chamber, and fully contacting with the electromagnetic rod 210 set on the other end wall, so as to adsorb as many magnetic particles in the material to be screened as possible; and, the outer wall of the electromagnetic rod 210 is also provided with a heating component 220, and the controller 300 is connected to the electromagnetic rod 210 and the heating component 220, so as to control the magnetic field strength of the electromagnetic rod 210 and the temperature of the heating component 220, and according to the different characteristics of the Curie temperature of different materials, the foreign matter of the magnetic particles in the material to be screened is collected at different temperatures without adsorbing the electrode material particles in the material to be screened. Specifically, the material to be screened is the positive electrode material of a sodium ion battery or a lithium iron phosphate battery. The battery electrode material magnetic particle detection and screening equipment can improve the collection efficiency and collection effect of magnetic particle foreign matter in the positive electrode material, and reduce the adsorption of positive electrode material particles, ensuring that subsequent magnetic particle detection results are more accurate.

[0033] Furthermore, the cylinder 100 includes a cylinder cover 120 and a cylinder body 110, wherein the cylinder body 110 is connected to the output end of the driving mechanism 101, and the cylinder cover 120 is provided with the electromagnetic rod 210, and the cylinder cover 120 is detachably connected to the cylinder body 110. The cylinder 100 configured in this way can conveniently place the material to be screened into the cylinder body, and then cover the cylinder cover 120 to achieve the sealing of the cylinder body 110. The detachable connection method is simple and reliable, and is easy to disassemble. After the cylinder cover 120 connected with the electromagnetic rod 210 is directly removed, the magnetic particle foreign matter on the electromagnetic rod 210 is collected, which is convenient for subsequent detection operations.

[0034] Optionally, the cylinder cover 120 is connected to the cylinder body 110 by flange. Figure 1 As shown, a connecting flange 130 is provided at the connection between the cylinder cover 120 and the cylinder body 110. The connecting flange 130 is fixed by two bolts, which can conveniently realize the detachable connection between the cylinder cover 120 and the cylinder body 110, and is stable and reliable after installation.

[0035] Specifically, a sealing ring 131 is provided at the flange connection between the cylinder cover 120 and the cylinder body 110. The provision of the sealing ring 131 can improve the sealing performance of the gap of the connecting flange 130, prevent the material to be screened from leaking from the gap, ensure the cleanliness of the operating environment, and avoid wasting the material to be screened. The sealing ring 131 is made of rubber, which is not specifically limited here, as long as it can achieve sealing.

[0036] Please continue to refer to Figure 1The outer wall of the axial end wall of the cylinder cover 120 is fixed with a dynamic sealing ring 121, and the inner wall of the dynamic sealing ring 121 is sealed and connected to the electromagnetic rod 210 and can rotate relatively. The dynamic sealing ring 121 can further seal the gap between the electromagnetic rod 210 and the outer wall of the axial end wall of the end cover to prevent the material to be screened from leaking therefrom.

[0037] Furthermore, the electromagnetic rod 210 is fixedly connected with a static sealing ring 122, and the static sealing ring 122 is sealed and relatively slidable with the inner wall of the axial end wall of the cylinder cover 120. The fine sealing ring can seal the gap between the electromagnetic rod 210 and the inner wall of the axial end wall of the cylinder cover 120, and can form two seals in combination with the dynamic sealing ring 121, and can also firmly fix the electromagnetic rod 210 on the end cover to prevent the electromagnetic rod 210 from falling off.

[0038] like Figure 1 As shown, the outer wall of the heating component 220 is also covered with a non-magnetic jacket 230. Under the magnetic attraction of the electromagnetic rod 210, the magnetic particle foreign matter is collected on the non-magnetic jacket 230. At this time, the electromagnetic rod 210 is removed, and the magnetic particle foreign matter is directly collected from the non-magnetic jacket 230 to prevent the magnetic particle foreign matter from contaminating the electromagnetic rod 210 and the heating component 220. The collection is more thorough to prevent the magnetic particle foreign matter from remaining, thereby improving the accuracy of subsequent magnetic particle detection.

[0039] Optionally, the non-magnetic jacket 230 is made of ceramic or plastic. The smooth surface of ceramic or plastic can prevent magnetic particles from being embedded in the grooves of the non-magnetic jacket 230, further ensuring that the magnetic particles are collected more thoroughly, thereby improving the accuracy of subsequent magnetic particle detection.

[0040] In this embodiment, a plurality of stirring parts 111 are provided on the circumferential inner wall of the cylinder 100, and the stirring parts 111 are extended toward the central axis of the cylinder 100. The stirring parts 111 can break up and stir the materials to be screened evenly, ensuring that the materials to be screened can fully contact the electromagnetic rod 210, and ensuring that the magnetic particle foreign matter is completely adsorbed by the electromagnetic rod 210.

[0041] Optionally, the heating assembly 220 includes a thermocouple, a heating element and a temperature control system, the thermocouple and the temperature control system are both communicatively connected to the controller 300, and the heating element is electrically connected to the temperature control system. The thermocouple may be one or more of S, R, B, N, K, J, and T-type thermocouples, the heating element may be one or more of a heating wire, a heating sheet, and a heating pad, the temperature control system transmits the temperature value fed back by the thermocouple to the PID (Proportional-Integral-Derivative) temperature control program of the controller 300, and the temperature control program controls the current value output to the heating element, thereby achieving temperature control, and the temperature control accuracy range includes 0.05°C to 100°C.

[0042] In this embodiment, the material of the cylinder cover 120, the cylinder body 110, the connecting flange 130, the stirring part 111 and the non-magnetic jacket 230 can be ceramic or plastic. Ceramics include alumina, zirconia, etc., and plastic materials include nylon, polyurethane, etc., which will not be repeated here.

[0043] The magnetic core of the electromagnetic rod 210 can be hydroxy iron powder, alloy material or amorphous material, the alloy material includes FeSi alloy, FeCr alloy, FeSiCr alloy, AlNiCo alloy, etc.; the amorphous material includes any one of Fe, Co, Ni, Si, Cr, P, B, Nb; the wire of the electromagnetic rod 210 can be ordinary wire or superconducting wire, the ordinary wire includes single crystal copper wire enameled wire, single crystal silver wire enameled wire, single crystal gold wire enameled wire, single crystal iron wire enameled wire, single crystal aluminum wire enameled wire, copper wire enameled wire, aluminum wire enameled wire, etc., the superconducting wire can be niobium titanium alloy wire (NbTi), magnesium boron alloy wire (MgB2), niobium tin alloy wire (Nb3Sn), etc. The electromagnetic rod 210 is made of a magnetic core and winding wire with uniform density. The magnetic field uniformity of the electromagnetic rod 210 is between 0.01% and 50%.

[0044] Furthermore, the driving mechanism 101 is selected to be a motor, which can be a variable frequency motor or a fixed frequency motor, and can achieve a rotation speed of 10 rpm to 1000 rpm.

[0045] Embodiment 1

[0046] Types of Magnetic Particles Curie temperature / ℃ iron 1043 cobalt 1400 nickel 627 Iron (III) oxide 948 Ferroferric oxide 858

[0047] In this embodiment 1, the material to be screened is a positive electrode material for a sodium ion battery. The above table shows the Curie temperature of the magnetic particle foreign matter in the positive electrode material. The Curie temperature test graph of the positive electrode material is as follows: Figure 2 shown.

[0048] It can be known that the material exhibits weak paramagnetism. If traditional permanent magnetic adsorption is used, part of the positive electrode material will be adsorbed, which has a great impact on the test results. At the same time, the positive electrode material will reach the Curie point at about 220°C, at which time demagnetization will occur. This temperature is lower than the Curie point of all the magnetic particle foreign matter in the above table. When using the battery electrode material magnetic particle detection and screening device in this embodiment, the temperature of the heating component 220 is adjusted to slightly above 220°C to demagnetize the positive electrode material. At this time, if the magnetic particle foreign matter is collected, the positive electrode material will not be collected, ensuring the accuracy of subsequent magnetic particle detection.

[0049] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. Battery electrode material magnetic particle detection and screening equipment, characterized in that: include: A cylinder (100), wherein the accommodating cavity of the cylinder (100) is used to accommodate materials to be screened, and the output end of a driving mechanism (101) is connected to the central axis of the end wall at one axial end of the cylinder (100) so that the cylinder (100) can rotate around its own axis; An electromagnetic rod (210), the electromagnetic rod (210) being inserted and sealed along the axial direction at the central axis of the end wall at the other axial end of the cylinder (100), and a heating component (220) being provided on the outer wall of the electromagnetic rod (210); A controller (300) is connected to the electromagnetic rod (210) and the heating component (220), and the controller (300) is capable of controlling the magnetic field strength of the electromagnetic rod (210) and the temperature of the heating component (220).

2. The battery electrode material magnetic particle detection and screening device according to claim 1, characterized in that: The cylinder (100) comprises a cylinder cover (120) and a cylinder body (110); the cylinder body (110) is connected to the output end of the driving mechanism (101); the cylinder cover (120) is provided with the electromagnetic rod (210); and the cylinder cover (120) is detachably connected to the cylinder body (110).

3. The battery electrode material magnetic particle detection and screening device according to claim 2, characterized in that: The cylinder cover (120) is flange-connected to the cylinder body (110).

4. The battery electrode material magnetic particle detection and screening device according to claim 3, characterized in that: A sealing ring (131) is provided at the flange connection between the cylinder cover (120) and the cylinder body (110).

5. The battery electrode material magnetic particle detection and screening device according to claim 2, characterized in that: A dynamic sealing ring (121) is fixedly connected to the outer wall of the axial end wall of the cylinder cover (120), and the inner wall of the dynamic sealing ring (121) is sealed and connected to the electromagnetic rod (210) and can rotate relatively.

6. The battery electrode material magnetic particle detection and screening device according to claim 5, characterized in that: The electromagnetic rod (210) is fixedly connected with a static sealing ring (122), and the static sealing ring (122) is sealed and connected to the inner wall of the axial end wall of the cylinder cover (120) and can slide relative to each other.

7. The battery electrode material magnetic particle detection and screening device according to claim 1, characterized in that: The outer wall of the heating component (220) is also covered with a non-magnetic outer jacket (230).

8. The battery electrode material magnetic particle detection and screening device according to claim 7, characterized in that: The non-magnetic outer shell (230) is made of ceramic or plastic.

9. The battery electrode material magnetic particle detection and screening device according to any one of claims 1 to 8, characterized in that: A plurality of stirring portions (111) are provided on the circumferential inner wall of the cylinder (100), and the stirring portions (111) are extended toward the central axis of the cylinder (100).

10. The battery electrode material magnetic particle detection and screening device according to any one of claims 1 to 8, characterized in that: The heating component (220) comprises a thermocouple, a heating element and a temperature control system, the thermocouple and the temperature control system are both communicatively connected to the controller (300), and the heating element is electrically connected to the temperature control system.

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