A positive electrode material precursor reaction device and preparation method thereof

Abstract

The present invention provides a positive electrode material precursor reaction device, comprising: a salt system; an alkali system; an inert gas system; a reactor; the salt system comprises a salt dissolving tank and a salt delivery pipeline, the salt delivery pipeline is sequentially connected in series with a salt filter, a salt deironer and a salt storage tank, the salt system also comprises a salt recovery tank connected to the salt filter and the salt deironer, and a salt circulation pipeline is provided between the salt storage tank and the salt recovery tank; the alkali system comprises an alkali dissolving tank and an alkali delivery pipeline, the alkali delivery pipeline is sequentially connected in series with an alkali filter, an alkali deironer and an alkali storage tank, the alkali system also comprises an alkali recovery tank connected to the alkali filter and the alkali deironer, and an alkali circulation pipeline is provided between the alkali storage tank and the alkali recovery tank. The present invention also provides a positive electrode material precursor preparation method applied to the positive electrode material precursor reaction device. Through the above-mentioned arrangement, the residual amount of salt stock solution and alkali stock solution is reduced, and it is easier for oxygen in the salt stock solution and the alkali stock solution to precipitate.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a reaction device for a positive electrode material precursor and a preparation method thereof. Background Art

[0002] With the popularization of electrification technology, new energy vehicles are gradually replacing fuel vehicles to become the mainstream means of transportation. Raw materials are formed from mineral mining and chemical smelting, and then precursor materials are synthesized through co-precipitation of raw materials. The precursor materials are proportioned and sintered to become positive electrode materials, which are then applied to the processing and manufacturing of battery cells.

[0003] Commonly used raw materials for precursor preparation include precipitant sodium hydroxide, chelating agent ammonia water, metal salts manganese sulfate, nickel sulfate and other compounds. The utilization rate of raw materials in precursor manufacturing is closely related to manufacturing costs. However, during the production and testing process, certain raw materials will remain inside the iron remover and filter.

[0004] A Chinese patent document with publication number CN215742284U discloses a multi-stage filtration device for a ternary precursor raw material solution, comprising a first storage tank, an iron remover, a filter, a second storage tank, a large precision filter, a small precision filter, and a third storage tank. The liquid outlet of the side wall of the first storage tank is connected to the liquid inlet of the iron remover through a pipe, the liquid outlet of the iron remover is connected to the liquid inlet at the top of the bag filter through a pipe, the liquid outlet of the side wall of the bag filter is connected to the liquid inlet at the top of the second storage tank, the liquid outlet of the side wall of the second storage tank is connected to the liquid inlet of the side wall of the large precision filter, the liquid outlet at the top of the large precision filter is connected to the liquid inlet of the side wall of the small precision filter, and the liquid outlet at the bottom of the small precision filter is connected to the liquid inlet at the top of the third storage tank.

[0005] Chinese patent document with publication number CN110270292A discloses a ternary precursor filtration and concentration system and its concentration method, including a deoiling and demagnetizing system connected to a raw material dissolution tank, and a thickening system connected to the deoiling and demagnetizing system. The deoiling and demagnetizing system includes a filter, and the filter is connected to a first transition tank. An oil remover and a demagnetizer are also provided between the discharge end of the filter and the feed end of the first transition tank. A stirring mechanism is provided between the first transition tanks, and the discharge end of the first transition tank is connected to the thickening system through a metering pump.

[0006] When these devices are used, there will inevitably be residual raw materials. If the residual raw materials are not processed for a long time, crystallization will occur and the pipeline will be blocked. At the same time, the filtration of the raw materials is relatively simple, and some impurities are still not filtered out. The oxygen therein will gradually cause the divalent metal ions in the residual raw materials to oxidize. If the oxidized ions participate in the reaction, it will cause the quality of the precursor product to decline. If the residual salt and alkali raw materials are discharged and collected and stored by manually opening the cover, it will increase the risk of oxidation of the raw materials and easily pollute the environment, increase the pressure of environmental protection treatment and endanger the health of workers. Summary of the Invention

[0007] In order to address the deficiencies of the prior art, the present invention provides a cathode material precursor reaction device and a preparation method thereof, which can fully filter out impurities in a raw liquid.

[0008] A cathode material precursor reaction device, comprising:

[0009] a salt system for forming a salt stock solution;

[0010] an alkali system for forming an alkali stock solution;

[0011] an inert gas system connected to the salt system and the alkali system and used to charge the salt system and the alkali system with inert gas at a preset pressure;

[0012] The reactor is connected to the salt system and the alkali system, and the salt solution and the alkali solution react in the reactor;

[0013] The salt system includes a salt dissolving tank for forming a salt stock solution and a salt delivery pipeline for delivering the salt stock solution in the salt dissolving tank to the reactor. The salt delivery pipeline is sequentially connected in series with a salt filter, a salt deironer and a salt storage tank. The salt system also includes a salt recovery tank respectively connected to the upstream end of the salt filter and the salt deironer and used to recover the residual salt stock solution in the salt filter and the salt deironer. A salt circulation pipeline is provided between the salt storage tank and the salt recovery tank.

[0014] The alkali system includes an alkali dissolution tank for forming an alkali stock solution and an alkali delivery pipeline for delivering the alkali stock solution in the alkali dissolution tank to the reactor. The alkali delivery pipeline is sequentially connected in series with an alkali filter, an alkali iron remover and an alkali storage tank. The alkali system also includes an alkali recovery tank respectively connected to the upstream end of the alkali filter and the alkali iron remover and used for recovering the residual alkali stock solution in the alkali filter and the alkali iron remover. An alkali circulation pipeline is provided between the alkali storage tank and the alkali recovery tank.

[0015] Preferably, the cathode material precursor reaction device includes a first state and a second state. A first drive assembly is provided in the salt delivery pipeline and / or the salt circulation pipeline, and a second drive assembly is provided in the alkali delivery pipeline and / or the alkali circulation pipeline. When the cathode material precursor reaction device is in the first state, the first drive assembly drives the salt stock solution to circulate in the salt delivery pipeline and the salt circulation pipeline, and the second drive assembly drives the alkali stock solution to circulate in the alkali delivery pipeline and the alkali circulation pipeline. When the cathode material precursor reaction device is in the second state, the salt stock solution in the salt system and the alkali stock solution in the alkali system flow into the reactor to react. After the salt stock solution and the alkali stock solution are circulated and fully filtered to remove impurities, they flow into the reactor to react, thereby forming a cathode material precursor with better sphericity and higher density, which is beneficial to improving the product quality of the cathode material precursor.

[0016] Furthermore, the positive electrode material precursor reaction device includes a first three-way valve, which includes a first interface, a second interface and a third interface. The first interface is connected to the salt storage tank, the second interface is connected to the salt recovery tank, and the third interface is connected to the reactor. This setting method can simplify the structure and number of pipelines.

[0017] Furthermore, when the cathode material precursor reaction device is in a first state, the first interface and the second interface are connected; when the cathode material precursor reaction device is in a second state and there is salt stock solution in the salt storage tank, the first interface and the third interface are connected; when the cathode material precursor reaction device is in the second state and there is no salt stock solution in the salt storage tank, the second interface and the third interface are connected. The three-way valve is used to achieve the conversion between the first and second states of the cathode material reaction device and to allow the salt stock solution in the salt storage tank or salt recovery tank to flow into the reactor. The structure is simple, practical, and low-cost.

[0018] Furthermore, the positive electrode material precursor reaction device includes a second three-way valve, the second three-way valve includes a fourth interface, a fifth interface and a sixth interface, the fourth interface is connected to the alkali storage tank, the fifth interface is connected to the alkali recovery tank, and the sixth interface is connected to the reactor. This setting method can simplify the structure and number of pipelines.

[0019] Furthermore, when the cathode material precursor reaction device is in the first state, the fourth interface and the fifth interface are connected; when the cathode material precursor reaction device is in the second state and there is alkali stock solution in the alkali storage tank, the fourth interface and the sixth interface are connected; when the cathode material precursor reaction device is in the second state and there is no alkali stock solution in the alkali storage tank, the fifth interface and the sixth interface are connected. The three-way valve is used to achieve the conversion between the first and second states of the cathode material reaction device and to allow the alkali stock solution in the alkali storage tank or alkali recovery tank to flow into the reactor, resulting in a simple, practical and low-cost structure.

[0020] Preferably, the first drive assembly includes a first drive state and a second drive state. When the first drive assembly is in the first drive state, the salt stock solution flows in the salt delivery pipeline and the salt circulation pipeline in a clockwise direction; when the first drive assembly is in the second drive state, the salt stock solution flows in the salt delivery pipeline and the salt circulation pipeline in a counterclockwise direction. This arrangement enables the salt filter and the salt deironer to fully filter out impurities in the salt stock solution from different directions, and enables the salt stock solution to fully remove residual salt stock solution in the salt filter and the salt deironer from different directions.

[0021] Preferably, the second drive assembly includes a third drive state and a fourth drive state. When the second drive assembly is in the third drive state, the alkali stock solution flows clockwise through the alkali delivery pipeline and the alkali circulation pipeline; when the second drive assembly is in the fourth drive state, the alkali stock solution flows counterclockwise through the alkali delivery pipeline and the alkali circulation pipeline. This arrangement enables the salt filter and the salt deironer to fully remove impurities from the salt stock solution from different directions, and enables the salt stock solution to fully remove residual salt stock solution from the salt filter and the salt deironer from different directions.

[0022] Preferably, the system further comprises an aging kettle and a filter, one end of which is connected to the reactor, and the other end of which is connected to the filter. After the slurry reacts in the reactor, it is transferred to the aging kettle for aging. After aging, it is transferred to the filter for filtration. After filtration, the precursor material containing the positive electrode material can be output.

[0023] The present invention also provides a method for preparing a cathode material precursor, using any of the cathode material precursor reaction devices described above, the preparation method comprising the following steps:

[0024] Step 1: stirring and dissolving a salt raw material and pure water in a salt dissolving tank to form a salt stock solution, and stirring and dissolving an alkali raw material in pure water to form an alkali stock solution;

[0025] Step 2: The salt solution is transported from the salt dissolution tank to the salt storage tank using a salt transport pipeline. During the transport process, it passes through a salt filter and a salt deironer to remove impurities and iron. The salt solution is then transported back from the salt storage tank to the salt recovery tank using a salt circulation pipeline. The salt solution in the salt recovery tank passes through the salt filter again and enters the salt transport pipeline for circulation.

[0026] The alkali stock solution is transported from the alkali dissolution tank to the alkali storage tank using the alkali transport pipeline. During the transportation process, it passes through the alkali filter and alkali iron remover to filter and remove impurities and iron. Then, the alkali stock solution is returned from the alkali storage tank to the alkali recovery tank using the alkali circulation pipeline. The alkali stock solution in the alkali recovery tank passes through the alkali filter again and enters the alkali transport pipeline to realize circulation.

[0027] During the circulation of the salt and alkali stock solutions, the inert gas system fills the salt system and the alkali system with inert gas of preset pressure, thereby removing oxygen from the salt and alkali stock solutions;

[0028] Step 3: transport the salt solution and alkali solution after the impurity removal, iron removal and oxygen removal in step 2 to the reactor for reaction.

[0029] Step 4, aging the slurry after the reaction is completed;

[0030] Step 5: Filter the aged slurry to obtain the final positive electrode material precursor material.

[0031] Beneficial effects of the present invention:

[0032] During the circulation process, the salt and alkali stock solutions remove residual salt and alkali stock solutions from the salt filter, salt deironer, alkali filter, and alkali deironer, reducing the residual amount of salt and alkali stock solutions and preventing blockage of the salt filter and salt deironer pipelines due to crystallization of residual salt stock solutions. Furthermore, as the salt and alkali stock solutions circulate, the inert gas at a preset pressure, introduced into the salt and alkali systems by the inert gas system, also circulates along with the salt and alkali stock solutions. At this point, the inert gas is fully in contact with and mixed with the salt and alkali stock solutions, providing a stirring function. The pressure of the inert gas facilitates the precipitation of impurity gases in the salt and alkali stock solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structural principle of the cathode material precursor reaction device of the present invention.

[0034] Figure 2 Schematic diagram of the structural principle of the salt circulation system of the present invention.

[0035] Figure 3 Schematic diagram of the structural principle of the alkali circulation system of the present invention.

[0036] Figure 4 It is a schematic diagram of the structural principle of the reactor of the present invention.

[0037] Figure 5 This is an electron microscope result diagram of Example 1 of the present invention.

[0038] Figure 6 This is an electron microscope result diagram of Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, a cathode material precursor reaction device 100 includes a salt system 11, an alkali system 12, an inert gas system 13, and a reactor 14. The salt system 11 and the alkali system 12 are both connected to the reactor 14. The salt system 11 converts the salt raw material into a salt stock solution and transfers it to the reactor 14. The alkali system 12 converts the alkali raw material into an alkali stock solution and transfers it to the reactor 14. The salt stock solution and the alkali stock solution undergo corresponding reactions in the reactor 14 to generate a slurry containing the cathode material precursor. The salt system 11 and the alkali system 12 are also at least partially connected to the inert gas system 13. The inert gas system 13 fills the salt system 11 and the alkali system 12 with an inert gas at a preset pressure to prevent the salt stock solution in the salt system 11 and the alkali stock solution in the alkali system 12 from being contaminated, thereby ensuring the product quality of the cathode material precursor. At the same time, the pressure of the inert gas exerts a force on the salt stock solution and the alkali stock solution, causing the impurity gases dissolved in the salt stock solution and the alkali stock solution to precipitate, further ensuring the product quality of the positive electrode material precursor.

[0041] like Figure 2 As shown, the salt system 11 includes a salt dissolving tank 111 and a salt delivery pipeline 112. The salt raw material is stirred and dissolved with pure water in the salt dissolving tank 111 to form a salt stock solution. The salt delivery pipeline 112 connects the salt dissolving tank 111 with the reactor 14. The salt dissolving tank 111 delivers the alkali stock solution to the reactor 14 through the salt delivery pipeline 112. A salt filter 113, a salt iron remover 114, and a salt storage tank 115 are connected in series from the upstream end to the downstream end of the salt stock solution flow direction in the salt delivery pipeline 112. Specifically, the salt delivery pipeline 112 includes a first flow pipeline 1121, a second flow pipeline 1122, and a third flow pipeline 1123. The first flow pipeline 1121 is disposed between the salt filter 113 and the salt dissolving tank 111, the second flow pipeline 1122 is disposed between the salt iron remover 114 and the salt storage tank 115, and the third flow pipeline 1123 is disposed between the salt storage tank 115 and the reactor 14. Among them, the salt filter 113 and the salt iron remover 114 are used to remove impurities and iron from the salt raw liquid, and the salt storage tank 115 provides the salt raw liquid participating in the reaction to the reactor 14.

[0042] The salt system 11 also includes a salt recovery tank 116, a first recovery line 117, and a second recovery line 118. The salt recovery tank 116 is connected to the upstream end of the salt filter 113 via the first recovery line 117. The salt recovery tank 116 is also connected to the salt deironing device 114 via the second recovery line 118. The residual salt solution in the salt filter 113 and the salt deironing device 114 can flow into the salt recovery tank 116. This arrangement reduces the amount of residual salt solution in the salt filter 113 and the salt deironing device 114 and avoids clogging of the salt filter 113 and the salt deironing device 114 due to crystallization of the residual salt solution.

[0043] The salt system 11 also includes a salt circulation pipeline 119 and a first drive assembly 211. The two ends of the salt circulation pipeline 119 are respectively connected to the salt recovery tank 116 and the salt storage tank 115. The first drive assembly 211 is arranged in the salt circulation pipeline 119 and / or the second circulation pipeline 1122. The salt circulation pipeline 119, the second circulation pipeline 1122, the first recovery pipeline 117, the salt recovery tank 116, the salt storage tank 115, the salt deironing device 114, the salt filter 113, and the first drive assembly 211 constitute a first circulation path of the salt raw liquid. The first drive assembly 211 can drive the salt raw liquid to circulate in the first circulation path, so that the salt raw liquid can pass through the salt filter 113 and the salt deironing device 114 multiple times to filter out impurities therein, so that the salt filter 113 and the salt deironing device 114 have a better filtering effect. The salt stock solution can also carry away the residual salt stock solution in the salt filter 113 and the salt deironer 114, thus avoiding the blockage of the salt filter 113 and the salt deironer 114 due to the crystallization of the residual salt stock solution; at the same time, it also avoids the need to manually clean the residual salt stock solution and its crystallization in the salt filter 113 and the salt deironer 114, thereby further reducing the risk of contamination of the salt filter 113 and the salt deironer 114 and saving maintenance costs. In addition, when the salt stock solution flows in the first circulation path, the inert gas of a preset pressure injected into the salt system 11 by the inert gas system 13 also circulates along with the salt stock solution. At this time, the inert gas and the salt stock solution are fully contacted and mixed and have a stirring function on the salt stock solution. The air pressure of the inert gas makes it easier for oxygen in the salt stock solution to precipitate. Among them, shut-off valves can be set in the first recovery pipeline 117 and the second recovery pipeline 118 to control the opening and closing of the first recovery pipeline 117 and the second recovery pipeline 118. While the salt filter 113 and the salt iron remover 114 fully discharge the residual salt solution therein, the salt solution can also be fully filtered during the circulation process.

[0044] The first driving component 211 includes a first driving state and a second driving state, such as Figure 2In the first circulation path shown, when the first drive assembly 211 is in the first driving state, the salt stock solution flows in a clockwise direction within the first circulation path; when the first drive assembly 211 is in the second driving state, the salt stock solution flows in a counterclockwise direction within the first circulation path. This configuration enables the salt filter 113 and the salt deironer 114 to fully remove impurities from the salt stock solution from different directions and allows the salt stock solution to fully remove residual salt stock solution from the salt filter 113 and the salt deironer 114.

[0045] A first control valve 11211 is provided in the first circulation conduit 1121. When the salt dissolving tank 111 replenishes salt solution into the salt storage tank 115, the first control valve 11211 opens the first circulation conduit 1121, allowing the salt solution to flow into the salt storage tank 115. When the salt storage tank 115 does not need to replenish salt solution or the salt solution in the salt dissolving tank 111 is low, the first control valve 11211 disconnects the first circulation conduit 1121 to prevent the salt solution in the first circulation path from coming into contact with the outside air, thereby preventing the salt solution in the first circulation path from being contaminated. A first driving member 11212 is also provided in the first circulation conduit 1121 to drive the salt solution from the salt dissolving tank 111 to the salt storage tank 115.

[0046] like Figure 3 As shown, the alkali system 12 includes an alkali dissolution tank 121 and an alkali delivery pipeline 122. The alkali raw material is stirred and dissolved with pure water in the alkali dissolution tank 121 to form an alkali stock solution. The alkali delivery pipeline 112 connects the alkali dissolution tank 121 with the reactor 14, and the alkali stock solution is delivered to the reactor 14 via the alkali delivery pipeline 122. From the upstream end to the downstream end of the flow direction of the saline alkali stock solution in the alkali delivery pipeline 122, an alkali filter 123, an alkali iron remover 124, and an alkali storage tank 125 are connected in series. Specifically, the alkali delivery pipeline 122 includes a fourth flow pipeline 1221, a fifth flow pipeline 1222, and a sixth flow pipeline 1223. The fourth flow pipeline 1221 is disposed between the alkali filter 123 and the alkali dissolution tank 121, the fifth flow pipeline 1222 is disposed between the alkali iron remover 124 and the alkali storage tank 125, and the sixth flow pipeline 1223 is disposed between the alkali storage tank 125 and the reactor 14. The alkali filter 123 and the alkali iron remover 124 are used to remove impurities and iron from the alkali stock solution, and the alkali storage tank 125 provides the reactor 14 with the alkali stock solution for the reaction.

[0047] The alkali system 12 also includes an alkali recovery tank 126, a third recovery line 127, and a fourth recovery line 128. The alkali recovery tank 126 is connected to the upstream end of the alkali filter 123 via the third recovery line 127. The alkali recovery tank 126 is also connected to the alkali iron remover 124 via the fourth recovery line 128. The residual alkali stock solution in the alkali filter 123 and the alkali iron remover 124 can flow into the alkali recovery tank 126. This arrangement reduces the amount of residual alkali stock solution in the alkali filter 123 and the alkali iron remover 124 and avoids clogging of the alkali filter 123 and the alkali iron remover 124 due to crystallization of the residual alkali stock solution.

[0048] The alkali system 12 also includes an alkali circulation pipeline 129 and a second drive assembly 221. The two ends of the alkali circulation pipeline 129 are respectively connected to the alkali recovery tank 126 and the alkali storage tank 125. The second drive assembly 221 is arranged in the alkali circulation pipeline 129 and / or the fifth circulation pipeline 1222. The alkali circulation pipeline 129, the fifth circulation pipeline 1222, the third recovery pipeline 127, the alkali recovery tank 126, the alkali storage tank 125, the alkali iron remover 124, the alkali filter 123, and the second drive assembly 221 constitute a second circulation path of the alkali raw liquid. The second drive assembly 221 can drive the alkali raw liquid to circulate in the second circulation path, so that the alkali raw liquid can pass through the alkali filter 123 and the alkali iron remover 124 multiple times to filter out impurities therein, thereby achieving a better filtering effect of the alkali filter 123 and the alkali iron remover 124. The alkali stock solution can also carry away the residual alkali stock solution in the alkali filter 123 and the alkali iron remover 124, thereby preventing the alkali filter 123 and the alkali iron remover 124 from being clogged due to the crystallization of the residual alkali stock solution. At the same time, it also avoids the need to manually clean the residual alkali stock solution and its crystallization in the alkali filter 123 and the alkali iron remover 124, thereby further reducing the risk of contamination of the alkali filter 123 and the alkali iron remover 124 and saving maintenance costs. In addition, when the alkali stock solution flows in the second circulation path, the inert gas of a preset pressure injected into the alkali system 12 by the inert gas system 14 also circulates along with the alkali stock solution. At this time, the inert gas and the alkali stock solution are fully contacted and mixed and have a stirring function on the alkali stock solution. The air pressure of the inert gas makes it easier for oxygen in the alkali stock solution to precipitate. Among them, shut-off valves can be set in the third recovery pipeline 127 and the fourth recovery pipeline 128 to control the opening and closing of the third recovery pipeline 127 and the fourth recovery pipeline 128. While the alkali filter 123 and the alkali iron remover 124 fully discharge the residual alkali stock solution therein, the alkali stock solution can also be fully filtered during the circulation process.

[0049] The second driving assembly 221 includes a third driving state and a fourth driving state, such as Figure 3In the second circulation path shown, when the second drive assembly 221 is in the third drive state, the alkali stock solution flows in a clockwise direction within the second circulation path; when the second drive assembly 221 is in the fourth drive state, the alkali stock solution flows in a counterclockwise direction within the second circulation path. This arrangement enables the alkali filter 123 and the alkali iron remover 124 to fully remove impurities from the alkali stock solution from different directions and allows the alkali stock solution to fully remove residual alkali stock solution from the alkali filter 123 and the alkali iron remover 124.

[0050] A second control valve 12211 is provided in the fourth circulation line 1221. When the alkali dissolving tank 121 replenishes the alkali storage tank 125 with alkali solution, the second control valve 12211 opens the fourth circulation line 1221, allowing the alkali solution to flow into the alkali storage tank 125. When the alkali storage tank 125 does not need to replenish alkali solution or the alkali solution in the alkali dissolving tank 121 is low, the second control valve 12211 shuts off the fourth circulation line 1221 to prevent the alkali solution in the second circulation path from coming into contact with the outside air, thereby preventing contamination of the alkali solution in the second circulation path. A second driving member 12212 is also provided in the fourth circulation line 1221 to drive the alkali solution from the alkali dissolving tank 121 to the alkali storage tank 125.

[0051] The positive electrode material precursor reaction device 100 includes a first state and a second state. When the positive electrode material precursor reaction device 100 is in the first state, the first driving component 211 drives the salt solution to circulate in the first circulation path, and the second driving component 221 drives the alkali solution to circulate in the second circulation path; when the positive electrode material precursor reaction device 100 is in the second state, the salt solution in the salt storage tank 115 and the alkali solution in the alkali storage tank 125 flow into the reactor 14 for related reactions.

[0052] like Figure 4As shown, the positive electrode material precursor reaction device 100 includes a first three-way valve 15, and the first three-way valve 15 includes a first interface 151, a second interface 152 and a third interface 153. The first interface 151 is connected to the third circulation pipeline 1123 and is connected to the salt storage tank 115, the second interface 152 is connected to the salt circulation pipeline 119 and is connected to the salt recovery tank 116, and the third interface 153 is connected to the third circulation pipeline 1123 and is connected to the reactor 14. When the positive electrode material precursor reaction device 100 is in the first state, the first interface 151 and the second interface 152 are connected so that the salt stock solution circulates in the first circulation path; when the positive electrode material precursor reaction device 100 is in the second state and there is a lot of salt stock solution in the salt storage tank 115, the first interface 151 and the third interface 153 are connected so that the salt stock solution in the salt storage tank 115 can enter the reactor 14; when the positive electrode material precursor reaction device 100 is in the second state and the salt stock solution in the salt storage tank 115 is exhausted, the second interface 152 and the third interface 153 are connected so that the salt stock solution in the salt recovery tank 116 can enter the reactor 14.

[0053] The positive electrode material precursor reaction device 100 includes a second three-way valve 16, which includes a fourth interface 161, a fifth interface 162 and a sixth interface 163. The fourth interface 161 is connected to the sixth circulation pipeline 1223 and is connected to the alkali storage tank 125. The fifth interface 162 is connected to the alkali circulation pipeline 129 and is connected to the alkali recovery tank 126. The sixth interface 163 is connected to the sixth circulation pipeline 1223 and is connected to the reactor 14. When the positive electrode material precursor reaction device 100 is in the first state, the fourth interface 161 and the fifth interface 162 are connected so that the alkali solution circulates in the first circulation path; when the positive electrode material precursor reaction device 100 is in the second state and there is a lot of alkali solution in the alkali storage tank 125, the fourth interface 161 and the sixth interface 163 are connected so that the alkali solution in the alkali storage tank 125 can enter the reactor 14; when the positive electrode material precursor reaction device 100 is in the second state and the alkali solution in the alkali storage tank 125 is used up, the fifth interface 162 and the sixth interface 163 are connected so that the alkali solution in the alkali recovery tank 126 can enter the reactor 14.

[0054] The cathode material precursor reaction device 100 further includes an aging kettle 17 and a filter 18. One end of the aging kettle 17 is connected to the reactor 14, and the other end of the aging kettle 17 is connected to the filter 18. After the slurry reacts in the reactor 14, it is transported to the aging kettle 17 for aging. After aging, it is transported to the filter 18 for filtration. After filtration, the slurry containing the cathode material precursor can be output.

[0055] The embodiment further provides a method for preparing a cathode material precursor, using the cathode material precursor reaction device 100 described above, the preparation method includes the following steps:

[0056] Step 1: stirring and dissolving a salt raw material and pure water in a salt dissolving tank to form a salt stock solution, and stirring and dissolving an alkali raw material in pure water to form an alkali stock solution;

[0057] Step 2: The salt solution is transported from the salt dissolution tank to the salt storage tank using a salt transport pipeline. During the transport process, it passes through a salt filter and a salt deironer to remove impurities and iron. The salt solution is then transported back from the salt storage tank to the salt recovery tank using a salt circulation pipeline. The salt solution in the salt recovery tank passes through the salt filter again and enters the salt transport pipeline for circulation.

[0058] The alkali stock solution is transported from the alkali dissolution tank to the alkali storage tank using the alkali transport pipeline. During the transportation process, it passes through the alkali filter and alkali iron remover to filter and remove impurities and iron. Then, the alkali stock solution is returned from the alkali storage tank to the alkali recovery tank using the alkali circulation pipeline. The alkali stock solution in the alkali recovery tank passes through the alkali filter again and enters the alkali transport pipeline to realize circulation.

[0059] During the circulation of the salt stock solution and the alkali stock solution, the inert gas system fills the salt system and the alkali system with inert gas of preset pressure, thereby removing oxygen from the salt stock solution and the alkali stock solution;

[0060] Step 3: transport the salt solution and alkali solution after the impurity removal, iron removal and oxygen removal in step 2 to the reactor for reaction.

[0061] Step 4, aging the slurry after the reaction is completed;

[0062] Step 5: Filter the aged slurry to obtain the final positive electrode material precursor material.

[0063] In the present invention, the salt stock solution is circulated in the first circulation path and the alkali stock solution is circulated in the second circulation path, so that the salt stock solution and the alkali stock solution can be filtered multiple times to remove impurities therein, and by filling the salt system 11 and the alkali system 12 with inert gas, the impurity gas in the salt stock solution and the alkali stock solution is removed and the salt stock solution and the alkali stock solution are prevented from being contaminated, so that the salt stock solution and the alkali stock solution react to form a positive electrode material precursor with better sphericity and more density. At the same time, the salt stock solution and the alkali stock solution also take away the residual salt stock solution and the residual alkali stock solution in the salt filter 113, the salt deironer 114, the alkali filter 123 and the alkali deironer 124 during the circulation process, avoiding the salt filter 113 and the salt deironer 114 from being blocked by the crystallization of the residual salt stock solution; at the same time, it also avoids the need to manually clean the residual salt stock solution and its crystallization in the salt filter 113 and the salt deironer 114, thereby further reducing the risk of contamination of the salt filter 113 and the salt deironer 114 and saving maintenance costs.

[0064] Example 1

[0065] Nickel sulfate, cobalt sulfate, and manganese sulfate were added to water at a molar ratio of nickel sulfate: cobalt sulfate: manganese sulfate = 6:2:2 to prepare 25 L of a 2 mol / L mixed salt solution. Liquid caustic soda with a mass fraction of 32% was prepared into a 5 mol / L alkali solution as a precipitant. Ammonia solution with a concentration of 0.5 mol / L as a complexing agent was stirred and mixed with the alkali solution to prepare 25 L of a mixed alkali solution.

[0066] Nitrogen is filled into the first circulation path and the second circulation path. In the nitrogen environment, the mixed salt solution is circulated in the first circulation path and the mixed alkali solution is circulated in the second circulation path to remove impurities and waste gas in the mixed salt solution and the mixed alkali solution.

[0067] The mixed salt solution was added to the reactor 14 at a rate of 2 L / h and the mixed alkali solution was added at a rate of 1.6 L / h for stirring reaction. The stirring speed was 300 rpm / min. During the reaction, the strength of the positive electrode material precursor was controlled to be 5.0±0.3 μm, and the pH value of the reaction system was 10.6±0.1.

[0068] After the reaction in the reactor 14 is completed, the slurry containing the positive electrode material precursor in the reactor 14 is transported to the aging reactor 17 for aging reaction. After aging for 5 hours, the slurry is transported to the filter 18 for filtration to obtain a precursor with a certain degree of dryness.

[0069] The precursor was dried in an oven and weighed to calculate the yield to be 99.5%. The experimental results are as follows Figure 5 shown.

[0070] Comparative Example 1

[0071] Nickel sulfate, cobalt sulfate, and manganese sulfate were added to water at a molar ratio of nickel sulfate: cobalt sulfate: manganese sulfate = 6:2:2 to prepare 25 L of a 2.0 mol / L mixed salt solution. Liquid caustic soda with a mass fraction of 32% was prepared into a 5 mol / L alkali solution as a precipitant. Ammonia solution with a concentration of 0.5 mol / L as a complexing agent was stirred and mixed with the alkali solution to prepare 25 L of a mixed alkali solution.

[0072] Nitrogen was filled into the first circulation path and the second circulation path. In the nitrogen environment, the mixed salt solution was added to the reactor 14 at a rate of 2 L / h and the mixed alkali solution was added at a rate of 1.6 L / h for stirring reaction. The stirring speed was 300 rpm / min. During the reaction, the particle size of the positive electrode material precursor was controlled to be 5.0±0.3 μm, and the pH value of the reaction system was 10.6±0.1.

[0073] After the reaction in the reactor 14 is completed, the slurry containing the positive electrode material precursor in the reactor 14 is transported to the aging reactor 17 for aging reaction. After aging for 5 hours, the slurry is transported to the filter 18 for filtration to obtain a precursor with a certain degree of dryness.

[0074] The precursor was dried in an oven and weighed to calculate the yield to be 99.4%. The experimental results are as follows Figure 6 shown.

[0075] Test Example 1

[0076] Bulk density test:

[0077] The obtained dry product was ground in a mortar for 20 minutes and sieved with 200 mesh. The product was then allowed to fall freely from the funnel into a measuring cylinder using the funnel method. The measuring cylinder had a capacity of 100 ml and the height of the funnel was 5 cm higher than the measuring cylinder. When the product filled the 100 ml scale line of the measuring cylinder, the product weight m1 was recorded to obtain the bulk density m1 / 100.

[0078] Tap density test:

[0079] The obtained dry product was ground in a mortar for 20 minutes and sieved through 200 mesh, and the product weight m2 was accurately weighed. The product was allowed to fall freely from the funnel into a measuring cylinder with a capacity of 100 ml and a height of 5 cm higher than the measuring cylinder. After the product was completely filled in the measuring cylinder, it was placed on a tap density meter and vibrated 3000 times. The volume T2 was read to obtain the tap density m2 / T2.

[0080] The test data comparison is shown in Table 1.

[0081] Table 1

[0082] Test items Example 1 Comparative Example 1 Bulk density g / cm3 0.98 0.82 Tap density g / cm3 1.35 1.16

[0083] The results show that this method effectively improves the tap density of the product, increases the stacking amount of the material under the same volume, and thus increases the energy density per unit volume.

Claims

1. A cathode material precursor reaction device, characterized in that: include: a salt system for forming a salt stock solution; an alkali system for forming an alkali stock solution; an inert gas system connected to the salt system and the alkali system, and used to fill the salt system and the alkali system with an inert gas of a preset pressure; A reactor, connected to the salt system and the alkali system, wherein the salt stock solution and the alkali stock solution react in the reactor; The salt system includes a salt dissolving tank for forming the salt stock solution and a salt delivery pipeline for delivering the salt stock solution in the salt dissolving tank to the reactor, wherein a salt filter, a salt deironing device and a salt storage tank are sequentially connected in series on the salt delivery pipeline, and the salt system also includes a salt recovery tank respectively connected to the upstream end of the salt filter and the salt deironing device and used for recovering the residual salt stock solution in the salt filter and the salt deironing device, and a salt circulation pipeline is provided between the salt storage tank and the salt recovery tank; The alkali system includes an alkali dissolving tank for forming the alkali stock solution and an alkali delivery pipeline for delivering the alkali stock solution in the alkali dissolving tank to the reactor, wherein an alkali filter, an alkali iron remover and an alkali storage tank are sequentially connected in series to the alkali delivery pipeline. The alkali system also includes an alkali recovery tank respectively connected to the upstream end of the alkali filter and the alkali iron remover and used to recover the residual alkali stock solution in the alkali filter and the alkali iron remover, and an alkali circulation pipeline is provided between the alkali storage tank and the alkali recovery tank; The positive electrode material precursor reaction device includes a first state and a second state, a first driving component is provided in the salt delivery pipeline and / or the salt circulation pipeline, and a second driving component is provided in the alkali delivery pipeline and / or the alkali circulation pipeline. When the positive electrode material precursor reaction device is in the first state, the first driving component drives the salt stock solution to circulate in the salt delivery pipeline and the salt circulation pipeline, and the second driving component drives the alkali stock solution to circulate in the alkali delivery pipeline and the alkali circulation pipeline; when the positive electrode material precursor reaction device is in the second state, the salt stock solution in the salt system and the alkali stock solution in the alkali system flow into the reactor to react; The first driving assembly includes a first driving state and a second driving state. When the first driving assembly is in the first driving state, the salt solution flows in the salt delivery pipeline and the salt circulation pipeline in a clockwise direction; when the first driving assembly is in the second driving state, the salt solution flows in the salt delivery pipeline and the salt circulation pipeline in a counterclockwise direction. The second drive assembly includes a third drive state and a fourth drive state. When the second drive assembly is in the third drive state, the alkali stock solution flows in the alkali delivery pipeline and the alkali circulation pipeline in a clockwise direction; when the second drive assembly is in the fourth drive state, the alkali stock solution flows in the alkali delivery pipeline and the alkali circulation pipeline in a counterclockwise direction.

2. The cathode material precursor reaction device according to claim 1, characterized in that: It includes a first three-way valve, which includes a first interface, a second interface and a third interface. The first interface is connected to the salt storage tank, the second interface is connected to the salt recovery tank, and the third interface is connected to the reactor.

3. The cathode material precursor reaction device according to claim 2, characterized in that: When the positive electrode material precursor reaction device is in the first state, the first interface and the second interface are connected; when the positive electrode material precursor reaction device is in the second state and there is the salt stock solution in the salt storage tank, the first interface and the third interface are connected; when the positive electrode material precursor reaction device is in the second state and there is no salt stock solution in the salt storage tank, the second interface and the third interface are connected.

4. The cathode material precursor reaction device according to claim 1, characterized in that: It includes a second three-way valve, which includes a fourth interface, a fifth interface and a sixth interface. The fourth interface is connected to the alkali storage tank, the fifth interface is connected to the alkali recovery tank, and the sixth interface is connected to the reactor.

5. The cathode material precursor reaction device according to claim 4, characterized in that: When the positive electrode material precursor reaction device is in the first state, the fourth interface and the fifth interface are connected; when the positive electrode material precursor reaction device is in the second state and there is the alkali stock solution in the alkali storage tank, the fourth interface and the sixth interface are connected; when the positive electrode material precursor reaction device is in the second state and there is no alkali stock solution in the alkali storage tank, the fifth interface and the sixth interface are connected.

6. The cathode material precursor reaction device according to claim 1, characterized in that: It also includes an aging kettle and a filter, one end of the aging kettle is connected to the reaction kettle, and the other end of the aging kettle is connected to the filter.

7. A method for preparing a cathode material precursor, characterized in that: Using the positive electrode material precursor reaction device according to any one of claims 1 to 6, the preparation method comprises the following steps: Step 1: stirring and dissolving a salt raw material and pure water in a salt dissolving tank to form a salt stock solution, and stirring and dissolving an alkali raw material in pure water to form an alkali stock solution; Step 2: The salt solution is transported from the salt dissolution tank to the salt storage tank using a salt transport pipeline. During the transport process, it passes through a salt filter and a salt deironer to remove impurities and iron. The salt solution is then transported back from the salt storage tank to the salt recovery tank using a salt circulation pipeline. The salt solution in the salt recovery tank passes through the salt filter again and enters the salt transport pipeline for circulation. The alkali stock solution is transported from the alkali dissolution tank to the alkali storage tank using the alkali transport pipeline. During the transportation process, it passes through the alkali filter and alkali iron remover to filter and remove impurities and iron. Then, the alkali stock solution is returned from the alkali storage tank to the alkali recovery tank using the alkali circulation pipeline. The alkali stock solution in the alkali recovery tank passes through the alkali filter again and enters the alkali transport pipeline to realize circulation. During the circulation of the salt stock solution and the alkali stock solution, the inert gas system fills the salt system and the alkali system with inert gas of preset pressure, thereby removing oxygen from the salt stock solution and the alkali stock solution; Step 3: transport the salt solution and alkali solution after the impurity removal, iron removal and oxygen removal in step 2 to the reactor for reaction. Step 4, aging the slurry after the reaction is completed; Step 5: Filter the aged slurry to obtain the final positive electrode material precursor material.

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