Method and device for supplementing missing elements in waste lithium battery positive electrode material

Abstract

The application provides a kind of waste lithium battery positive material supplement missing element mixing method and device, comprising: supplement raw material and solvent stirring mixing, obtain mixed solution;Mixed solution is transferred to spray mechanism by conveying mechanism;The mixed solution is sprayed into the missing element waste lithium battery positive material by the spray mechanism, and the missing element waste lithium battery positive material is mixed evenly with the supplement raw material by the mixing mechanism.The beneficial effects of the present application: the missing element waste lithium battery positive material can be mixed evenly with the supplement raw material.

Description

Technical Field

[0001] This invention belongs to the field of waste lithium battery recycling and regeneration, and in particular relates to a method and apparatus for mixing missing elements in the cathode material of waste lithium batteries. Background Technology

[0002] After the dismantling and sorting of spent lithium-ion batteries, cathode materials with minimal or reversible structural changes can be directly repaired. By adding lithium salts or other compounds to the cathode materials and then subjecting them to high-temperature roasting, lithium ions are brought into the lattice sites of the failed cathode material through particle contact, thereby restoring its electrochemical performance. It is important to note that before high-temperature repair, the cathode material and lithium salt must be uniformly mixed, and the reactant particle size must be appropriate to facilitate lithium ion diffusion during roasting, resulting in a cathode active material with better repair performance.

[0003] Currently, lithium replenishment is mainly achieved through two processes: solid-phase lithium replenishment and liquid-phase lithium replenishment. Solid-phase lithium replenishment involves mixing the waste lithium-ion battery material with a lithium source through solid-solid mixing, while liquid-phase lithium replenishment disperses the waste lithium-ion cathode material in a LiOH aqueous solution. Solid-phase lithium replenishment, a dry-mixing process, suffers from problems such as uneven mixing and insufficient contact between the replenishing lithium source and the waste lithium-ion battery material. Liquid-phase lithium replenishment requires low-temperature drying followed by high-temperature calcination, but the solvent drying process is prone to uneven lithium salt concentration distribution and agglomeration, complicating subsequent processing of the sintered material. Therefore, new methods and approaches are needed to address these issues. Summary of the Invention

[0004] In view of this, the present invention aims to propose a method and apparatus for mixing missing elements in waste lithium battery cathode materials to solve the above-mentioned technical shortcomings. Through the process of "emulsion atomization-solid fluidization", the mixing of waste lithium battery cathode materials and missing elements is realized.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for mixing missing elements in waste lithium battery cathode materials includes the following steps:

[0007] S1. Mix the lithium iron phosphate cathode material of the waste lithium battery to be repaired with a solvent to obtain a mixture;

[0008] S2. After the mixture obtained from S1 is transferred to the spraying mechanism through the conveying mechanism, steps S3 and S4 are started simultaneously.

[0009] S3. The spraying mechanism sprays the mixture onto the waste battery cathode material that is missing elements;

[0010] S4. The mixing mechanism is used to mix the waste lithium battery cathode material with missing elements evenly with the supplementary raw materials.

[0011] Furthermore, the supplementary raw material mentioned in step S1 is one or more components selected from NiSO4, CoSO4, MnSO4, LiNO3, Li2CO3, LiOH, and LiOOCH3.

[0012] The solvent mentioned in step S1 is one or more components of water and alcohol.

[0013] Furthermore, the waste lithium battery cathode material in step S1 includes one or more of lithium iron phosphate, ternary lithium, lithium cobalt oxide, lithium manganese oxide, and lithium nickel oxide.

[0014] Furthermore, the waste lithium battery cathode material with missing elements mentioned in step S3 is lithium iron phosphate with one or two missing elements of lithium and iron; ternary lithium with one or more missing elements of lithium, nickel, cobalt, and manganese; lithium manganese oxide with one or two missing elements of lithium and manganese; and lithium nickel oxide with one or two missing elements of lithium and nickel.

[0015] Furthermore, the mixed material described in step S4 has a moisture content of less than 20%.

[0016] Furthermore, a mixing device for replenishing missing elements in waste lithium battery cathode materials includes a stirring mechanism, a conveying mechanism, a spraying mechanism, and a mixing mechanism connected in sequence. The stirring mechanism includes a solution storage container and a stirring paddle, used to stir and mix the waste lithium iron phosphate cathode material to be repaired with a solvent to obtain a mixture. The conveying mechanism is located above the stirring mechanism and is used to convey the mixture to the spraying mechanism. The spraying mechanism is located at the rear end of the conveying mechanism and is used to atomize the mixture. The mixing mechanism is located below the spraying mechanism and is used to mix the atomized liquid with the missing element lithium battery cathode material to be repaired evenly.

[0017] Furthermore, the stirring mechanism includes a storage container and a stirring paddle. The storage container is equipped with the stirring paddle and is used for storing the supplement and the dispersion medium. The stirring paddle is used for stirring and dissolving the supplement and the dispersion medium.

[0018] Furthermore, the stirring mechanism includes at least one stirring paddle and one feeding port.

[0019] Furthermore, the conveying mechanism is corrosion-resistant and does not introduce metal impurities, and includes a front-end conveying pipe, a conveying pump, and a rear-end conveying pipe. One end of the front-end conveying pipe is connected to the stirring mechanism, and the other end of the front-end conveying pipe is connected to one end of the rear-end conveying pipe through the conveying pump. The other end of the rear-end conveying pipe is connected to the spraying mechanism.

[0020] Furthermore, the size of the particles sprayed by the spraying mechanism is in the range of 1-5 μm.

[0021] Furthermore, the mixing mechanism has an adjustable stirring frequency of 5-50Hz.

[0022] Compared with existing technologies, the mixing method and apparatus for replenishing missing elements in waste lithium battery cathode materials described in this invention have the following advantages:

[0023] The present invention discloses a mixing method and apparatus for replenishing missing elements in waste lithium battery cathode materials, which can uniformly mix waste lithium battery cathode materials with missing elements and supplementary raw materials; compared with liquid phase mixing, the mixed material of this method does not need to be dried, which can reduce energy consumption and lower costs; compared with solid phase mixing, the mixed material of this method is more uniform; the apparatus is compatible with different solvents and supplementary raw materials through "emulsion atomization-solid fluidization". Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 This is a schematic diagram of the mixing device according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the charge-discharge curve in Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the charge-discharge curve in Embodiment 2 of the present invention;

[0028] Figure 4 This is a schematic diagram of the charge-discharge curve in Comparative Example 1 according to an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the charge-discharge curve in Comparative Example 2 of the present invention;

[0030] Figure 6 This is a schematic diagram of the charge-discharge curve in Comparative Example 3 of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Mixing mechanism; 2. Conveying mechanism; 3. Spraying mechanism; 4. Mixing mechanism. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., 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 with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] like Figures 1 to 6 As shown, a method for replenishing missing elements in waste lithium battery cathode materials mainly includes the following four steps, based on the production sequence:

[0038] S1: Mix the supplementary raw materials with the solvent to obtain a mixture;

[0039] S2: The mixture obtained from mixing in S1 is transferred to the spraying mechanism via a conveying mechanism;

[0040] S3: The spraying mechanism sprays the mixture into the cathode material of the waste battery that is missing elements;

[0041] S4: The mixing mechanism ensures that the waste lithium battery cathode material lacking elements is mixed evenly with the supplementary raw materials.

[0042] It is worth noting that: Step S4 starts at the same time as step S3. Through the interaction between the mixing mechanism and the spraying mechanism, the waste lithium battery cathode material with missing elements is mixed evenly with the supplementary raw materials.

[0043] In a preferred embodiment of the present invention, the supplementary raw material mentioned in S1 is one or more components selected from NiSO4, CoSO4, MnSO4, LiNO3, Li2CO3, LiOH, and LiOOCH3.

[0044] In a preferred embodiment of the present invention, the solvent mentioned in S1 is one or more components of water and alcohol.

[0045] In a preferred embodiment of the present invention, the cathode material of the waste lithium battery includes one or more of lithium iron phosphate, ternary lithium, lithium cobalt oxide, lithium manganese oxide, and lithium nickel oxide.

[0046] In a preferred embodiment of the present invention, the waste lithium battery cathode material with missing elements mentioned in S3 is lithium iron phosphate with one or two missing elements of lithium and iron; ternary lithium with one or more missing elements of lithium, nickel, cobalt, and manganese; lithium manganese oxide with one or two missing elements of lithium and manganese; and lithium nickel oxide with one or two missing elements of lithium and nickel.

[0047] This patent application also provides a mixing device for replenishing missing elements in waste battery materials, comprising a stirring mechanism 1, a conveying mechanism 2, a spraying mechanism 3, and a mixing mechanism 4 connected in sequence. The stirring mechanism 1 includes a solution storage container and a stirring paddle for replenishing the mixing and emulsification of raw materials and dispersion media. The conveying mechanism 2 is positioned above the stirring mechanism 1 and conveys the mixture to the spraying mechanism 3. The spraying mechanism 3 is positioned at the rear end of a peristaltic pump and atomizes the mixture. The mixing mechanism 4 is positioned below the spraying mechanism 3 and mixes the atomized liquid with the missing elements in the lithium battery cathode material to be repaired, ensuring uniform mixing. This device ensures that the missing elements in the lithium battery cathode material to be repaired are uniformly mixed.

[0048] In a preferred embodiment of the present invention, the stirring mechanism 1 includes a storage container and a stirring paddle. The storage container is used for storing supplements and dispersion media, and its temperature is adjustable. The stirring speed of the stirring paddle is adjustable, and the supplements and dispersion media are dissolved or emulsified under the action of the stirring paddle.

[0049] In a preferred embodiment of the present invention, the conveying mechanism 2 is disposed above the stirring mechanism 1 and is used to convey the mixture to the spraying mechanism 3; the conveying mechanism 2 is corrosion resistant and does not introduce metal impurities, and includes a front-end conveying pipe, a conveying pump, and a rear-end conveying pipe.

[0050] In a preferred embodiment of the present invention, the spraying mechanism 3 is disposed at the rear end of the conveying mechanism 2 and is used to atomize the mixture; the particle size sprayed by the spraying mechanism 3 is in the range of 1-5μm.

[0051] In a preferred embodiment of the present invention, the mixing mechanism 4 is disposed below the spraying mechanism 3, and uses supplementary raw materials and waste lithium-ion battery materials by stirring. The stirring frequency of the mixing mechanism 4 is adjustable from 5 to 50 Hz.

[0052] In a preferred embodiment of the present invention, the mixed material has a moisture content of less than 20%.

[0053] Advantages of this application:

[0054] This method can uniformly mix waste lithium battery cathode materials lacking elements with supplementary raw materials; compared with liquid phase mixing, the mixed material does not need to be dried, which can reduce energy consumption and lower costs; compared with solid phase mixing, the mixed material is more uniform; this device is compatible with different solvents and supplementary raw materials through "emulsion atomization-solid fluidization".

[0055] Example 1

[0056] 3.2g of lithium hydroxide monohydrate and 28g of water were mixed using the stirring mechanism 1 in this patent. The lithium hydroxide solution was then sprayed onto the mixing mechanism 4 via the conveying mechanism 2 in this patent. Through the interaction between the mixing mechanism 4 and the spraying mechanism 3, 150g of lithium iron phosphate cathode material from the waste lithium-ion battery to be repaired was uniformly mixed with the lithium hydroxide aqueous solution. After high-temperature repair, the mixed lithium iron phosphate exhibited a 0.1C discharge specific capacity of 155mAh / g, as shown in the charge-discharge curve. Figure 2 .

[0057] Example 2

[0058] 2.8g of lithium carbonate was dispersed in 28g of alcohol and mixed using the stirring mechanism 1 of this patent. The lithium carbonate mixture was then sprayed onto the mixing mechanism 4 via the conveying mechanism 2 of this patent. Through the interaction between the mixing mechanism 4 and the spraying mechanism 3, 150g of lithium iron phosphate cathode material from the waste lithium-ion battery to be repaired was uniformly mixed with the lithium carbonate mixture. After high-temperature repair, the mixed lithium iron phosphate exhibited a 0.1C discharge specific capacity of 145mAh / g, as shown in the charge-discharge curve. Figure 3 .

[0059] Comparative Example 1

[0060] 150g of lithium iron phosphate cathode material from waste lithium batteries to be repaired was directly subjected to high-temperature repair to obtain repaired lithium iron phosphate. Its 0.1C discharge specific capacity was 107mAh / g. The charge-discharge curve is shown in [Figure number missing]. Figure 4.

[0061] Comparative Example 2

[0062] 3.2g of lithium hydroxide monohydrate was dissolved in 150g of water. 150g of the lithium iron phosphate cathode material from the waste lithium-ion battery to be repaired was added to the lithium hydroxide monohydrate solution and stirred to obtain a slurry. After drying at 110℃, the slurry was repaired at high temperature to obtain repaired lithium iron phosphate. Its 0.1C discharge specific capacity was 151mAh / g. Its charge-discharge curve is shown in [Figure number missing]. Figure 5 .

[0063] Comparative Example 3

[0064] 2.8g of lithium carbonate and 150g of lithium iron phosphate cathode material from waste lithium batteries to be repaired were mixed using a solid-solid mixing method. The mixture was then subjected to high-temperature repair to obtain repaired lithium iron phosphate, which had a 0.1C discharge specific capacity of 128mAh / g. Its charge-discharge curve is shown in [Figure number missing]. Figure 5 .

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for mixing waste lithium battery cathode materials to replenish missing elements, implemented by a waste lithium battery cathode material replenishment and mixing device, characterized in that: The method includes the following steps: S1. Mix the supplementary raw materials with the solvent to obtain a mixture; S2. After the mixture obtained from S1 is transferred to the spraying mechanism (3) through the conveying mechanism (2), steps S3 and S4 are started simultaneously. S3, the spraying mechanism (3) sprays the mixture into the waste lithium battery cathode material lacking elements, and the particle size sprayed by the spraying mechanism (3) is in the range of 1-5μm; S4. The waste lithium battery cathode material with missing elements is mixed evenly with the supplementary raw materials through the mixing mechanism (4). The mixing mechanism (4) has a stirring frequency in the range of 5-50Hz. After mixing, the material has a water content of less than 20% and is slightly moist. It can be directly connected to high temperature repair without drying. The supplementary raw material mentioned in step S1 is one or more components selected from NiSO4, CoSO4, MnSO4, LiNO3, Li2CO3, and LiOH. The solvent mentioned in step S1 is one or more components of water and alcohol; The cathode materials of waste lithium batteries include one or more of lithium iron phosphate, ternary lithium, lithium cobalt oxide, lithium manganese oxide, and lithium nickel oxide. The missing elements in the waste lithium battery cathode material mentioned in step S3 are: lithium iron phosphate with one or two missing elements of lithium and iron; ternary lithium with one or more missing elements of lithium, nickel, cobalt, and manganese; lithium manganese oxide with one or two missing elements of lithium and manganese; and lithium nickel oxide with one or two missing elements of lithium and nickel. The waste lithium battery cathode material replenishment and mixing device includes a stirring mechanism (1), a conveying mechanism (2), a spraying mechanism (3), and a mixing mechanism (4) connected in sequence. The stirring mechanism (1) includes a storage solution container and a stirring paddle, used to stir and mix the replenishing raw materials and solvent to obtain a mixture. The conveying mechanism (2) is located above the stirring mechanism (1) and is used to convey the mixture to the spraying mechanism (3). The spraying mechanism (3) is located at the rear end of the conveying mechanism (2) and is used to atomize the mixture. The mixing mechanism (4) is located below the spraying mechanism (3) and is used to mix the atomized liquid with the waste lithium battery cathode material with missing elements evenly. Mix the waste lithium battery cathode material lacking the missing elements with the supplementary raw materials evenly.

2. The method for mixing missing elements in waste lithium battery cathode materials according to claim 1, characterized in that: The stirring mechanism (1) includes a storage container and a stirring paddle. The storage container is equipped with a stirring paddle and is used to store raw materials and solvents. The stirring paddle is used to stir, dissolve, and replenish raw materials and solvents.

3. The method for mixing missing elements in waste lithium battery cathode materials according to claim 1, characterized in that: The conveying mechanism (2) is corrosion resistant and does not introduce metal impurities. It includes a front conveying pipe, a conveying pump, and a rear conveying pipe. One end of the front conveying pipe is connected to the stirring mechanism (1), and the other end of the front conveying pipe is connected to one end of the rear conveying pipe through the conveying pump. The other end of the rear conveying pipe is connected to the spraying mechanism (3).

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