A device for separating and enriching non-magnetic foreign matters of lithium ion battery cathode materials

Abstract

The utility model discloses a kind of lithium ion battery positive electrode material non-magnetic foreign matter separation enrichment device, including bottom shell, hollow inner ring, negative outer ring, positive electrode column, positive electrode and negative electrode;The inside of the bottom shell is sequentially provided with positive electrode column, hollow inner ring and negative outer ring from inside to outside, lithium ion battery positive electrode material is filled between the hollow inner ring and positive electrode column;The side of the hollow inner ring close to negative outer ring is provided with diaphragm, and electrolyte is added;The end of the positive electrode and negative electrode respectively extends into bottom shell interior and is connected with positive electrode column, negative outer ring.This utility model assembles lithium ion positive electrode material into battery positive electrode and carries out charge and discharge, the negative outer ring of enrichment non-magnetic foreign matter copper, zinc element is sequentially cleaned, digested, inductively coupled plasma emission spectrometer quantitative test, can obtain accurate non-magnetic foreign matter copper zinc element content, with good practicability.

Description

Technical Field

[0001] This utility model belongs to the technical field of lithium-ion battery cathode material separation equipment, specifically relating to a device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode materials. Background Technology

[0002] In recent years, lithium-ion batteries have become the most widely used type of rechargeable battery due to their advantages such as high energy density, high capacity, and long cycle life. For example, lithium-ion batteries have been applied in electronic devices, satellites, spacecraft, and underwater robots. A lithium-ion battery mainly consists of four parts: a positive electrode, a negative electrode, an electrolyte, and a separator. The positive electrode material plays a crucial role in lithium-ion batteries. However, during the manufacturing process, it is inevitable that some elemental or compound metals containing Fe, Cu, Cr, Ni, and Zn will be introduced. These include magnetic impurities such as iron, nickel, and chromium, and non-magnetic impurities such as copper and zinc. The presence of these metallic impurities can cause battery self-discharge or even explosion, severely impacting the performance of lithium-ion batteries. Therefore, it is necessary to remove these metallic impurities.

[0003] Current product standards for lithium-ion battery cathode materials all have technical requirements for the content of magnetic materials, and there is also a corresponding national standard for testing, GB / T 41704-2022, "Test Methods for Lithium-ion Battery Cathode Materials: Determination of Magnetic Foreign Matter Content and Residual Alkali Content". However, there are currently no testing and technical indicators for non-magnetic foreign matter, and no relevant standards have been published.

[0004] Existing patent CN116297607A discloses a method for measuring metallic foreign matter in cathode materials, including the following steps: Step 1, weigh the sample, spread the sample flat on an air-jet sieve, and begin air-jet sieving until the volume of material on the sieve no longer changes, at which point sieving is complete; Step 2, use small tweezers to pick up a cut piece of conductive tape and attach the foreign matter on the sieve to the conductive tape; Step 3, place the conductive tape with the foreign matter attached in the sample chamber of a scanning electron microscope (SEM), obtain the shape and size of the foreign matter particles using SEM, and perform energy dispersive spectroscopy (EDS) analysis on the particles identified as foreign matter. This method can quickly separate metallic foreign matter and lithium nickel cobalt manganese oxide through air-jet sieving, allowing both magnetic and non-magnetic foreign matter to be separated from the cathode material, facilitating subsequent detection. However, it is a semi-quantitative analysis method and cannot accurately obtain the content of non-magnetic copper and zinc elements.

[0005] Existing patent CN115096983A discloses a method for detecting the content of metal impurities in cathode materials. The method includes the following steps: S1. Taking lithium-ion battery cathode material and physically pulverizing it to obtain powder with a particle size D99 ≤ 1 μm; S2. Mixing the powder with a solvent to obtain a suspension, filtering, and obtaining filter residue with a particle size > 1 μm; S3. Determining the content of metal impurities in the filter residue using ICP technology, and calculating the metal impurity content in the lithium-ion battery cathode material. This detection method can effectively enrich metal impurities in lithium-ion battery cathode materials, and then, combined with ICP technology, can accurately determine the content of metal impurities. Furthermore, this method can detect not only the content of magnetic metal impurities but also the content of non-magnetic metal impurities. However, this method may result in the loss of the analyte or may measure the total amount of non-magnetic elements and compounds instead of the content of impurity elements, thus failing to accurately reflect the content of non-magnetic foreign matter such as copper and zinc. Utility Model Content

[0006] The purpose of this invention is to provide a device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode materials, aiming to achieve the separation and enrichment of non-magnetic foreign matter such as copper and zinc.

[0007] This utility model is mainly achieved through the following technical solutions:

[0008] A device for separating and enriching non-magnetic foreign matter in lithium-ion battery positive electrode material includes a bottom shell, a hollow inner ring, a negative outer ring, a positive electrode column, a positive electrode, and a negative electrode. The bottom shell contains, from the inside out, a positive electrode column, a hollow inner ring, and a negative outer ring. Lithium-ion battery positive electrode material is filled between the hollow inner ring and the positive electrode column. A separator is provided on the side of the hollow inner ring closest to the negative outer ring, and an electrolyte is added thereon. The ends of the positive and negative electrodes extend into the bottom shell and are connected to the positive electrode column and the negative outer ring, respectively.

[0009] To better realize this utility model, it further includes a cover, the top of which is detachably provided with a cover, and the ends of the positive electrode and the negative electrode are respectively connected to the positive electrode post and the negative electrode outer ring.

[0010] To better realize this utility model, the positive electrode and the negative electrode each include a base and a plug-in electrode head. The middle and edge of the cover are respectively provided with snap-fit ​​holes corresponding to the base. The base is snapped into the snap-fit ​​holes, and the plug-in electrode heads of the positive electrode and the negative electrode pass through the snap-fit ​​holes and are connected to the positive electrode post and the negative electrode outer ring, respectively.

[0011] To better realize this utility model, the positive electrode post and the negative electrode outer ring are respectively provided with insertion holes corresponding to the insertion electrode head.

[0012] To better realize this utility model, the hollow inner ring is further made of stainless steel, and the side wall of the stainless steel ring is provided with several through holes.

[0013] To better realize this utility model, the bottom of the inner part of the bottom shell is provided with a mounting groove corresponding to the positive electrode post, and the outer side of the mounting groove is provided with a snap-fit ​​groove corresponding to the hollow inner ring.

[0014] To better realize this utility model, it further includes a pressure ring, wherein the top of the negative electrode outer ring is provided with a pressure ring, and the pressure ring is used to compact the lithium-ion battery positive electrode material.

[0015] The beneficial effects of this utility model are as follows:

[0016] This invention involves inserting lithium-ion battery positive electrode material into the inner side of a hollow inner ring and compacting it with a ring-shaped clamping ring. A separator is assembled on the outer side of the hollow inner ring, and electrolyte is added. The positive and negative electrodes are then charged and discharged separately to achieve the separation and enrichment of non-magnetic copper and zinc impurities in the lithium-ion battery positive electrode material. The lithium-ion positive electrode material is assembled into a battery positive electrode and charged and discharged. The negative electrode outer ring, enriched with non-magnetic copper and zinc impurities, is then sequentially cleaned, digested, and quantitatively tested using inductively coupled plasma atomic emission spectrometry (ICP-AES) to obtain accurate content of non-magnetic copper and zinc impurities. This invention has a simple structure, is easy to install and operate, accumulates fewer impurities, and can obtain relatively accurate content of non-magnetic copper and zinc impurities, making it highly practical. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the separation and enrichment device of this utility model;

[0018] Figure 2 This is a top view of the separation and enrichment device of this utility model;

[0019] Figure 3 for Figure 2 Schematic diagram of the AA section;

[0020] Figure 4 This is a cross-sectional view of the bottom shell;

[0021] Figure 5 A schematic diagram of the hollow inner ring structure;

[0022] Figure 6 This is a schematic diagram of the connection structure between the pressure ring and the negative electrode outer ring.

[0023] The components are: 1-bottom shell, 2-cover, 3-positive electrode, 4-negative electrode, 5-negative outer ring, 6-positive column, 7-hollow inner ring, 8-mounting groove, and 9-pressure ring. Detailed Implementation

[0024] Example 1:

[0025] A device for separating and enriching non-magnetic foreign matter in lithium-ion battery positive electrode material includes a bottom shell 1, a hollow inner ring 7, a negative outer ring 5, a positive electrode column 6, a positive electrode 3, and a negative electrode 4. The positive electrode column 6, the hollow inner ring 7, and the negative outer ring 5 are arranged sequentially from the inside to the outside of the bottom shell 1. The space between the hollow inner ring 7 and the positive electrode column 6 is filled with lithium-ion battery positive electrode material. A separator is provided on the side of the hollow inner ring 7 near the negative outer ring 5, and an electrolyte is added thereto. The ends of the positive electrode 3 and the negative electrode 4 extend into the bottom shell 1 and are connected to the positive electrode column 6 and the negative outer ring 5, respectively.

[0026] Preferably, such as Figures 1-3 As shown, the system also includes a cover 2, which is detachably mounted on the top of the bottom shell 1. The ends of the positive electrode 3 and the negative electrode 4 are respectively connected to the positive electrode post 6 and the negative electrode outer ring 5. Further, the positive electrode 3 and the negative electrode 4 each include a base and a connector electrode head. The middle and edge of the cover 2 are respectively provided with snap-fit ​​holes corresponding to the base. The base engages with the snap-fit ​​holes, and the connector electrode heads of the positive electrode 3 and the negative electrode 4 pass through the snap-fit ​​holes and connect to the positive electrode post 6 and the negative electrode outer ring 5, respectively. The positive electrode post 6 and the negative electrode outer ring 5 are respectively provided with connector holes corresponding to the connector electrode heads.

[0027] Preferably, such as Figure 5 As shown, the hollow inner ring 7 is a stainless steel ring, and the sidewall of the stainless steel ring has several through holes. Further, as... Figure 4 As shown, a mounting groove 8 is provided in the center of the inner bottom of the bottom shell 1 corresponding to the positive electrode post 6, and a snap-fit ​​groove is provided on the outer side of the mounting groove 8 corresponding to the hollow inner ring 7. Further, as... Figure 6 As shown, the top of the negative electrode outer ring 5 is detachably provided with an annular pressure ring 9 for compacting the filled lithium-ion battery positive electrode material. The pressure ring 9 is provided with a through clearance hole corresponding to the insertion hole of the negative electrode outer ring 5.

[0028] This invention involves inserting lithium-ion battery positive electrode material into the inner side of a hollow inner ring 7 and compacting it with a pressure ring 9. A separator is assembled on the outer side of the hollow inner ring 7, and electrolyte is added. The positive electrode 3 and negative electrode 4 are then charged and discharged separately to achieve the separation and enrichment of non-magnetic foreign matter copper and zinc in the lithium-ion battery positive electrode material. This invention assembles the lithium-ion positive electrode material into a battery positive electrode for charging and discharging. The negative electrode outer ring 5, enriched with non-magnetic foreign matter copper and zinc, is then sequentially cleaned, digested, and quantitatively tested using inductively coupled plasma atomic emission spectrometry (ICP-AES) to obtain accurate content of non-magnetic foreign matter copper and zinc. This invention has a simple structure, is easy to install and operate, accumulates fewer impurities, and can obtain relatively accurate content of non-magnetic foreign matter copper and zinc, making it highly practical.

[0029] Example 2:

[0030] A device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode materials, such as... Figures 1-3 As shown, the device includes a bottom shell 1, a cover 2, a hollow inner ring 7, a positive electrode post 6, a negative electrode outer ring 5, a positive electrode 3, and a negative electrode 4. The cover 2 is detachably mounted on the top of the bottom shell 1. The positive electrode post 6, the hollow inner ring 7, and the negative electrode outer ring 5 are sequentially installed inside the bottom shell 1 from the inside out. The space between the positive electrode post 6 and the hollow inner ring 7 is filled with lithium-ion battery positive electrode material. The ends of the positive electrode 3 and the negative electrode 4 are respectively connected to the positive electrode post 6 and the negative electrode outer ring 5. The space between the positive electrode post 6 and the hollow inner ring 7 is filled with a mixture of lithium-ion battery positive electrode material, a conductive agent, and a binder. Figure 5 As shown, the sidewall of the hollow inner ring 7 has several through holes for the transfer of lithium ions during lithium-ion charging and discharging. Preferably, the hollow inner ring 7 is a stainless steel ring.

[0031] Preferably, such as Figure 1 and Figure 3 As shown, the top of the bottom shell 1 is detachably connected to the cover 2 by bolts. One end of the positive electrode 3 and the negative electrode 4 respectively passes through the cover 2 and extends into the bottom shell 1, correspondingly inserting into the positive electrode cavity and the negative electrode outer ring 5. Further, the positive electrode 3 and the negative electrode 4 each include a base and an electrode insertion head. Mounting holes are respectively provided at the center and edge of the cover 2. The base engages with the mounting holes, and the electrode insertion head passes through the mounting holes and is correspondingly inserted into the positive electrode cavity and the negative electrode outer ring 5.

[0032] Preferably, such as Figure 6 As shown, it also includes a pressure ring 9, which is disposed between the outer ring and the cover 2. The pressure ring 9 is used to compact the filled lithium-ion battery positive electrode material.

[0033] In use, the lithium-ion battery positive electrode material, conductive agent, and binder are mixed evenly, dried, and then filled into the filling position of the positive electrode material, i.e., the inner side of the hollow inner ring 7. The mixture is then compacted using a ring-shaped pressing ring 9, which can be removed after compaction. A separator is assembled on the outer side of the hollow inner ring 7, and electrolyte is added. Aluminum foil is assembled on the outer ring 5 of the negative electrode. The positive electrode 3 and negative electrode 4 are charged and discharged respectively, achieving the separation and enrichment of non-magnetic foreign matter, copper and zinc, in the lithium-ion battery positive electrode material.

[0034] This invention utilizes electrochemical principles to separate and enrich non-magnetic copper and zinc elements in lithium-ion battery cathode materials. The dissolution voltage of Cu is 3.382V, and that of Zn is 2.2772V. Non-magnetic copper and zinc elements oxidize at the cathode and are reduced and precipitated at the anode. This allows for the complete enrichment of all non-magnetic copper and zinc elements at the anode, rather than other copper-zinc alloys and compounds that interfere with the accuracy of the test. Based on this principle, this invention assembles lithium-ion cathode materials into battery cathodes for charging and discharging. The outer ring 5 of the anode enriched with non-magnetic copper and zinc elements is sequentially cleaned, digested, and quantitatively tested using inductively coupled plasma atomic emission spectrometry (ICP-AES) to obtain accurate content of non-magnetic copper and zinc elements. This invention can also be extended to the determination of non-magnetic copper and zinc elements in lithium-ion battery anode materials and sodium-ion battery materials, demonstrating good practicality.

[0035] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode materials, characterized in that, The device includes a bottom shell (1), a hollow inner ring (7), a negative outer ring (5), a positive electrode column (6), a positive electrode (3), and a negative electrode (4). The bottom shell (1) is provided with the positive electrode column (6), the hollow inner ring (7), and the negative outer ring (5) in sequence from the inside to the outside. The hollow inner ring (7) and the positive electrode column (6) are filled with lithium-ion battery positive electrode material. A diaphragm is provided on the side of the hollow inner ring (7) near the negative outer ring (5), and an electrolyte is added thereon. The ends of the positive electrode (3) and the negative electrode (4) extend into the bottom shell (1) and are connected to the positive electrode column (6) and the negative outer ring (5), respectively.

2. The device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode material according to claim 1, characterized in that, It also includes a cover (2), the top of the bottom shell (1) is detachably provided with a cover (2), and the ends of the positive electrode (3) and the negative electrode (4) are respectively connected to the positive electrode column (6) and the negative electrode outer ring (5).

3. The device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode material according to claim 2, characterized in that, The positive electrode (3) and negative electrode (4) respectively include a base and a plug-in electrode head. The middle and edge of the cover (2) are respectively provided with snap-fit ​​holes corresponding to the base. The base is snapped into the snap-fit ​​holes, and the plug-in electrode heads of the positive electrode (3) and negative electrode (4) pass through the snap-fit ​​holes and are connected to the positive electrode post (6) and the negative electrode outer ring (5).

4. The device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode material according to claim 3, characterized in that, The positive electrode post (6) and the negative electrode outer ring (5) are respectively provided with insertion holes corresponding to the insertion electrode head.

5. The device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode material according to claim 1, characterized in that, The hollow inner ring (7) is a stainless steel ring, and the side wall of the stainless steel ring is provided with several through holes.

6. The device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode material according to any one of claims 1-5, characterized in that, The bottom of the base shell (1) has an installation groove (8) in the middle of the inner bottom corresponding to the positive electrode column (6), and the outer side of the installation groove (8) has a snap-fit ​​groove corresponding to the hollow inner ring (7).

7. The device for separating and enriching non-magnetic foreign matter in lithium-ion battery cathode material according to claim 1, characterized in that, It also includes a pressure ring (9), which is provided on the top of the negative electrode outer ring (5). The pressure ring (9) is used to compact the positive electrode material of the lithium-ion battery.

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