阅读说明：本技术 基于新型反应器的三元材料前驱体的制备方法 (Preparation method of ternary material precursor based on novel reactor ) 是由 游高平 晁锋刚 颜志梁 石小东 张东学 王楚明 苏德开 钟庆磊 于 2020-12-29 设计创作，主要内容包括：本发明提供了一种基于新型反应器的三元材料前驱体的制备方法,包括：S1,按配比将Ni:Co:Mn盐溶液、碱溶液和氨水通过进料管(11)加入到反应容器(12)内部并同时通入惰性气体反应,其中,Ni:Co:Mn盐溶液流量为300L/h,碱液流量为96L/h,氨水流量为15L/h；S2,当反应0.8～1.5小时后,全开溢流阀(17)、提固阀门(22)以及回流阀门(27),以及并将排清阀门(24)打开10～25％；S3,最后通过观察窗(28)观察让固含量体积占比保持在19％左右,降低氨水浓度达到6-7g/L,并实测pH达到11.2-11.4最终得到中间产物。(The invention provides a preparation method of a ternary material precursor based on a novel reactor, which comprises the following steps: s1, adding a Ni-Co-Mn salt solution, an alkali solution and ammonia water into a reaction container (12) through a feeding pipe (11) according to the proportion, and introducing inert gas for reaction, wherein the flow rate of the Ni-Co-Mn salt solution is 300L/h, the flow rate of the alkali solution is 96L/h, and the flow rate of the ammonia water is 15L/h; s2, after reacting for 0.8-1.5 hours, fully opening the overflow valve (17), the lifting and fixing valve (22) and the backflow valve (27), and opening the clear discharge valve (24) by 10-25%; and S3, finally, observing through an observation window (28) to keep the solid content volume ratio at about 19%, reducing the ammonia water concentration to 6-7g/L, and actually measuring the pH value to 11.2-11.4 to finally obtain an intermediate product.)

1. A preparation method of ternary material precursor based on a novel reactor is characterized in that the novel reactor comprises the following steps: a reaction unit (10) and a lifting unit (20);

the reaction unit (10) comprises a reaction container (12), an overflow pipeline (18) arranged at the upper part of the reaction container (12) and an overflow valve (17) arranged on the overflow pipeline (18);

the lifting and fixing unit (20) comprises: the device comprises a lifting and fixing device (23), a lifting and fixing pipeline (21) respectively connected to the upper part of the lifting and fixing device (23) and the upper part of the reaction container (12), a lifting and fixing valve (22) arranged on the lifting and fixing pipeline, a clear discharge pipeline (24) connected to the upper part of the lifting and fixing device (23), an observation port (28) connected to the top of the lifting and fixing device (23), a clear discharge valve (25) and an observation window (28) arranged on the clear discharge pipeline (24), a return pipeline (26) respectively connected to the bottom of the lifting and fixing device (23) and the bottom of the reaction container (12), and a return valve (27) arranged on the return pipeline (26); and a plurality of layers of grid plates (234) which are arranged in a stacked manner and used for accumulating and rapidly precipitating the ternary precursor are transversely arranged in the lifting and fixing device (23);

the preparation method comprises the following steps:

s1, adding a Ni-Co-Mn salt solution, an alkali solution and ammonia water into a reaction container (12) through a feeding pipe (11) according to the proportion, and introducing inert gas for reaction, wherein the flow rate of the Ni-Co-Mn salt solution is 300L/h, the flow rate of the alkali solution is 96L/h, and the flow rate of the ammonia water is 15L/h;

s2, after reacting for 0.8-1.5 hours, fully opening the overflow valve (17), the lifting and fixing valve (22) and the backflow valve (27), and opening the clear discharge valve (24) by 10-25%;

and S3, finally, observing through the observation window (28) to keep the solid content volume ratio at about 19%, reducing the ammonia water concentration to 6-7g/L, and actually measuring the pH value to 11.2-11.4 to finally obtain an intermediate product.

2. The method of preparing a ternary material precursor of claim 1, further comprising:

and S4, carrying out post-treatment on the intermediate product to obtain a ternary material precursor.

3. The method of claim 1, wherein the bottom of the lifter (23) is in an inverted cone shape, and the space volume of the lifter is 1/3-1/2 of the effective volume of the reaction vessel (12).

4. A method for preparing a ternary material precursor according to claim 3, wherein each grid plate (234) comprises a plurality of obliquely arranged grids (2342), and the grids (2342) between two adjacent grid plates (234) are interconnected.

5. The method for preparing the ternary material precursor of claim 4, wherein the number of the grid plates (234) is 2 to 5.

6. The method for producing a ternary material precursor according to claim 1, wherein the ratio of Ni to Co to Mn is 50.5%: 19.8%: 29.7% or according to 60.5%: 19.8%: 19.7% by mole.

7. The method for preparing the ternary material precursor according to claim 4, wherein in step S2, after 1 hour of reaction, the overflow valve (17), the lifting valve (22) and the return valve (27) are fully opened, and the purge valve (24) is opened by 10-25%.

8. The method of claim 4, wherein the axis of each grid (2342) forms an angle of 15 ° to 80 ° with the lifter (23).

9. The method of claim 4, wherein the grid (2342) between two adjacent layers of grid plates (234) is crossed in the oblique direction.

10. The method for preparing the ternary material precursor according to claim 4, wherein the reflow pipe (26) comprises two first bending discharging sections, a second bending discharging section connected with the first bending discharging section, a first extending section extending along the extending direction of the first bending discharging section, and a second extending section extending along the opposite direction of the second bending discharging section, and a first spiral push rod (262) and a second spiral push rod (264) are respectively arranged in the first extending section and the second extending section.

Technical Field

The invention relates to a preparation method of a ternary material precursor based on a novel reactor.

Background

Lithium ion secondary batteries having high safety and high capacity have been widely noticed and used due to the environmental problems and the remarkable problem of energy consumption. The preparation method of the lithium ion cathode material precursor is also perfected.

In the preparation process of the nickel-cobalt-manganese ternary hydroxide, methods for improving the solid content of the slurry are various, wherein a thickener is an important mode for preparing the nickel-cobalt-manganese ternary hydroxide with narrow particle size distribution. At present, the method using the thickener has high cost, complex equipment operation, high equipment maintenance expense and low fault-tolerant rate.

Disclosure of Invention

The invention provides a preparation method of a ternary material precursor based on a novel reactor, which can effectively solve the problems.

The invention is realized by the following steps:

a method for preparing a ternary material precursor based on a novel reactor, the novel reactor comprising: a reaction unit and a solid lifting unit;

the reaction unit comprises a reaction container, an overflow pipeline arranged at the upper part of the reaction container and an overflow valve arranged on the overflow pipeline;

a lifting and fixing unit comprising: the device comprises a lifting and fixing device, a lifting and fixing pipeline respectively connected to the upper part of the lifting and fixing device and the upper part of the reaction container, a lifting and fixing valve arranged on the lifting and fixing pipeline, a clear discharge pipeline connected to the upper part of the lifting and fixing device, an observation port connected to the top of the lifting and fixing device, a clear discharge valve and an observation window arranged on the clear discharge pipeline, a return pipeline respectively connected to the bottom of the lifting and fixing device and the bottom of the reaction container, and a return valve arranged on the return pipeline; the interior of the lifting and fixing device is transversely provided with a plurality of layers of grid plates which are arranged in a stacked mode and used for accumulating and rapidly precipitating the ternary precursor;

the preparation method comprises the following steps:

s1, adding a Ni-Co-Mn salt solution, an alkali solution and ammonia water into the reaction container through a feed pipe according to the proportion, and introducing inert gas for reaction, wherein the flow rate of the Ni-Co-Mn salt solution is 300L/h, the flow rate of the alkali solution is 96L/h, and the flow rate of the ammonia water is 15L/h;

s2, after reacting for 0.8-1.5 hours, fully opening the overflow valve, the lifting and fixing valve and the backflow valve, and opening the clear discharge valve by 10-25%;

and S3, finally, observing through the observation window to keep the solid content volume ratio at about 19%, reducing the ammonia water concentration to 6-7g/L, and actually measuring the pH value to 11.2-11.4 to finally obtain an intermediate product.

The invention has the beneficial effects that: according to the invention, a plurality of grating plates for accumulating and rapidly precipitating the ternary precursor are arranged in the solid lifting device, and through the reasonable design of parameters such as height, inclination angle and layer number of the grating, the overflow path of slurry entering the solid lifting device and the retention time in the solid lifting device can be effectively changed, so that the purpose of rapidly precipitating the material in the solid lifting device is achieved, the solid content of the slurry is finally improved, and the slurry can obtain good sphericity; in addition, the method has the characteristics of simple operation, easy industrial production and the like.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of a novel reactor provided by an embodiment of the invention.

FIG. 2 is a schematic structural diagram of a solids-lifting unit in the novel reactor provided by the embodiment of the invention.

FIG. 3 is a top view of a grid plate in a lifting unit of the novel reactor provided by an embodiment of the present invention.

Fig. 4 is a flow chart of a method for preparing a ternary precursor by using the novel reactor according to an embodiment of the present invention.

FIG. 5 shows Ni prepared in comparative example 1 of the present invention_0.5Co_0.2Mn_0.3(OH)₂Scanning electron micrographs of (A) and (B).

FIG. 6 shows Ni prepared in example 1 of the present invention_0.5Co_0.2Mn_0.3(OH)₂Scanning electron micrographs of (A) and (B).

Fig. 7 is a flow chart of a method for preparing a ternary precursor by using the novel reactor, which is provided by another embodiment of the invention.

FIGS. 8 and 9 are Ni prepared in example 2 of the present invention_0.6Co_0.2Mn_0.2(OH)₂Scanning electron micrographs (different magnifications).

FIGS. 10 to 11 show Ni prepared in comparative example 2 of the present invention_0.6Co_0.2Mn_0.2(OH)₂Scanning electron micrographs of (A) and (B).

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1, the present invention provides a novel reactor. The novel reactor is suitable for preparing ternary precursors.

The novel reactor comprises:

the reaction unit 10 comprises a reaction vessel 12, a feeding pipe 11 arranged in the reaction vessel 12, a stirring assembly arranged in the reaction vessel 12, a temperature control assembly 15 sleeved outside the bottom of the reaction vessel 12, an overflow pipeline 18 arranged on the upper part of the reaction vessel 12 and an overflow valve 17 arranged on the overflow pipeline 18;

the lifting and fixing unit 20 includes: the device comprises a lifting and fixing device 23 for accumulating and rapidly precipitating the ternary precursor, a lifting and fixing pipeline 21 respectively connected to the upper part of the lifting and fixing device 23 and the upper part of the reaction container 12, a lifting and fixing valve 22 arranged on the lifting and fixing pipeline 21, a drain pipeline 24 connected to the upper part of the lifting and fixing device 23, an observation port 28 connected to the top of the lifting and fixing device 23, a drain valve 25 and an observation window 28 arranged on the drain pipeline 24, a return pipeline 26 respectively connected to the bottom of the lifting and fixing device 23 and the bottom of the reaction container 12, and a return valve 27 arranged on the return pipeline 26. The supernatant valve 25 is used for discharging the supernatant liquid containing sulfur.

The feed pipe 11 is used for introducing nickel-cobalt-manganese salt solution prepared according to a proportion. The reaction vessel 12, the stirring member and the temperature control member 15 may be of any conventional structure, and will not be described in detail herein. Further, the overflow pipe 18 is flush with the lifting and fixing pipe 21. The reaction unit 10 may further include an exit conduit 16.

Referring to fig. 2-3, the lifting device 23 is a top bucket, the bottom is an inverted cone, and the space volume is 1/3-1/2 of the effective volume of the reaction vessel 12. The material of the lifting and fixing device 23 is not limited, and can be any one of 316L steel and PP. Further, a plurality of layers of grid plates 234 which are arranged in a stacked manner and used for accumulating and rapidly precipitating the ternary precursor are transversely arranged in the lifting and fixing device 23; each grid plate 234 includes a plurality of grids 2342 arranged in an inclined manner, and the grids 2342 between two adjacent grid plates 234 are communicated with each other and the inclined directions of the grids 2342 are crossed. It can be understood that by arranging the grids 2342 obliquely and crossing the oblique directions, the solid can be accumulated and rapidly precipitated through continuous collision, and finally the overall morphology of the ternary precursor is improved. Preferably, the number of the grid plates 234 is 2-5 layers. It can be understood that when the number of grating plates 234 is small, the number of collisions is low and accumulation is difficult, and rapid sedimentation and morphology lifting are achieved; when the number is large, the particle size tends to be excessively large. Further, the angle formed by the axis of each grid 2342 and the lifter 23 is controlled to allow solids to accumulate and rapidly settle through continuous collision. Too small an angle results in too small a collision area, and too large an angle tends to accumulate in grating plate 234. Therefore, preferably, the axis of each grid 2342 forms an angle of 15 ° to 80 ° with the anchor 23. More preferably, the axis of each grid 2342 forms an angle of 25 ° to 35 ° with the anchor 23. In one embodiment, the axis of each grid 2342 forms an angle of about 30 ° with the lifting device 23.

Each grid plate 234 is 10-30 cm in height, and the distance from the top grid plate 234 to the top of the lifter 23 is 30-50 cm. The shape of each grid 2342 is not limited and can be selected according to actual needs; the shape of each grid 2342 may be a regular or irregular structure. In one embodiment, each grid 2342 is a regular hexagonal structure with sides of 5-20 centimeters.

As a further improvement, the backflow pipeline 26 includes two first bending discharging sections, a second bending discharging section connected to the first bending discharging section, a first extending section extending along the extending direction of the first bending discharging section, and a second extending section extending along the second bending discharging section in the opposite direction, and the first extending section and the second extending section are respectively provided with a first spiral push rod 262 and a second spiral push rod 264. The screw ejector pin can play a role in dredging when the backflow pipeline 26 is blocked.

Referring to fig. 4, an embodiment of the present invention further provides a method for preparing a ternary material precursor based on the novel reactor, including the following steps:

s1, adding a Ni/Co/Mn salt solution, an alkali solution and ammonia water into the reaction container 12 through a metering pump on a feeding pipe 11 according to the proportion, and simultaneously introducing inert gas for reaction, wherein the flow rate of the Ni/Co/Mn salt solution is 300L/h, the flow rate of the alkali solution is 96L/h, the flow rate of the ammonia water is 15L/h, and the Ni/Co/Mn ratio is 50.5%: 19.8%: 29.7% by mole;

s2, after reacting for 0.8-1.5 hours, fully opening the overflow valve 17, the lifting valve 22 and the return valve 27, and opening the purge valve 24 by 10-25%, wherein the excessive reaction liquid loss caused by the excessive opening of the purge valve 24 is not beneficial to discharging excessive sulfate radicals when the excessive reaction liquid loss is too small;

s3, finally, observing through the observation window 28 to keep the solid content volume ratio at about 19%, reducing the ammonia water concentration to 6-7g/L, and actually measuring the pH value to 11.2-11.4 to finally obtain an intermediate product;

and S4, finally, carrying out post-treatment on the intermediate product to obtain the ternary material precursor.

Example 1:

adding Ni, Co and Mn into a mixture according to the weight percentage of 50.5%: 19.8%: 29.7% of nickel in molar proportionAdding cobalt manganese salt solution, 28% mass concentration alkali solution and 20% mass concentration ammonia water into the reaction container 12 by metering pump, and introducing 1m of feed liquid³The nitrogen gas/h, the flow of the salt solution is 300L/h, the flow of the alkaline solution is 96L/h, the flow of the ammonia water is 15L/h, the ammonia salt and alkaline metering pump is sequentially started to inject the reaction material liquid into the reaction container 12 to start the reaction, after the reaction is started for 1 hour, the overflow valve 17, the lifting and fixing valve 22 and the backflow valve 27 are fully opened, the clear valve 24 is opened for 15 percent, the material color is observed to keep the solid content volume ratio at about 19 percent, the ammonia water concentration is reduced to 6-7g/L, and the intermediate product is finally obtained when the actually measured pH value reaches 11.2-11.4. Finally, the intermediate product is stirred and aged for 3 hours by the frequency of 10-20 Hz; removing the mother liquor by a centrifugal machine; adding the solid with the mother liquor removed into a sodium hydroxide solution with the concentration of 0.8mol/L and the temperature of 60 ℃, and circularly stirring for 15-60 minutes to obtain slurry; washing the slurry until the content of sodium element is less than or equal to 150ppm, and then drying and dehydrating; finally, the mixture is subjected to batch mixing and demagnetizing, and the mixture is sieved by a 300-mesh sieve to obtain Ni_0.5Co_0.2Mn_0.3(OH)₂。

Comparative example 1:

the same as example 1 except that: after one hour of the reaction, the relief valve 17 was opened fully, and the lift valve 22, the return valve 27, and the purge valve 24 were held closed.

Referring to FIGS. 5 to 6 together, FIG. 5 shows Ni, a final product obtained in comparative example 1_0.5Co_0.2Mn_0.3(OH)₂In FIG. 5, the sulfur content reached about 1305 ppm. FIG. 6 shows Ni as a final product obtained in example 1_0.5Co_0.2Mn_0.3(OH)₂It can be seen from the figure that the use of the solid-lifting unit 20 can significantly improve the technical problems of too much small particles Dmin and poor sphericity in the continuous process, and simultaneously can reduce the sulfur content of the finished product to about 790, thereby improving the washing effect. The reduction of the sulfur content is realized by opening the clear discharge valve 24, specifically, sulfate ions can be discharged along with supernatant, and the sulfate content in the slurry is reduced.

Referring to fig. 7, an embodiment of the present invention further provides a method for preparing a ternary material precursor based on the novel reactor, including the following steps:

s1', adding a Ni/Co/Mn salt solution, an alkali solution and ammonia water into the reaction container 12 through a metering pump according to the proportion, and introducing inert gas for reaction, wherein the flow rate of the Ni/Co/Mn salt solution is 300L/h, the flow rate of the alkali solution is 96L/h, the flow rate of the ammonia water is 15L/h, and the Ni/Co/Mn ratio is 60.5%: 19.8%: 19.7% by mole;

s2, after reacting for 0.8-1.5 hours, fully opening the overflow valve 17, the lifting valve 22 and the return valve 27, and opening the drain valve 24 by 10-25%;

s3, finally, observing through the observation window 28 to keep the solid content volume ratio at about 19%, reducing the ammonia water concentration to 6-7g/L, and actually measuring the pH value to 11.2-11.4 to finally obtain an intermediate product;

and S4, finally, carrying out post-treatment on the intermediate product to obtain the ternary material precursor.

Example 2:

the same as example 1 except that: ni, Co and Mn are calculated according to a ratio of 60.5%: 19.8%: 19.7% by mole, Ni was finally obtained_0.6Co_0.2Mn_0.2(OH)₂。

Comparative example 2:

the same as example 2 except that: after one hour of the reaction, the relief valve 17 was opened fully, and the lift valve 22, the return valve 27, and the purge valve 24 were held closed.

Referring to FIGS. 8-11 together, FIGS. 8-9 show Ni, the final product obtained in example 2_0.6Co_0.2Mn_0.2(OH)₂Wherein D is₀＝6.89μm，D₁₀＝9.6um，D₅₀＝11.4μm，D₉₀＝13.6μm，D_max18.4 μm; the precursor has good sphericity, and the secondary particles are formed by agglomerating flaky primary particles with large length-diameter ratio. Tap density 2.29g/cm³Specific surface area 6.1218m²G, S content 926 ppm. FIGS. 10 to 11 are comparative examples2 final product Ni_0.6Co_0.2Mn_0.2(OH)₂The tap density of which is 2.19g/cm³Specific surface area 4.45m²G, S content 1250ppm, D₀＝7.42μm，D₁₀＝9.63um，D₅₀＝11.1μm，D₉₀＝12.7μm，D_maxAs 16.1 μm, in addition, it can be seen from the figure that this type of precursor is rough in surface and poor in sphericity.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.