Electrode slurry manufacturing device and manufacturing method

Abstract

The present invention relates to an apparatus for producing slurry for an electrode, comprising: a mixing section which receives and mixes an electrode active material, a conductive material, a binder, and a solvent to produce a slurry for an electrode; a flow path which samples the slurry for an electrode from the mixing section; a weight measuring section which measures the weight of the slurry sample for an electrode; a cleaning section which cleans the inside of the weight measuring section; and an exhaust section which circulates air inside the weight measuring section.

Description

[Technical Field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0145344, filed with the Korean Intellectual Property Office on October 28, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an apparatus and method for producing electrode slurry, and more particularly to an apparatus and method for producing electrode slurry that can inspect the solid content and quality of electrode slurry in real time. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and have the potential to be small and have large capacities. Due to the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. In secondary batteries, the electrode assembly attached inside the battery case is a chargeable and dischargeable power generating element consisting of a laminated structure of electrodes and separators.

[0005] Electrode assemblies can be broadly classified into a jelly-roll type in which a separator is interposed between a sheet-like positive electrode and a negative electrode coated with an active material and wound up; a stack type in which multiple positive electrodes and negative electrodes are stacked in order with a separator interposed between them; and a stack / folding type in which a stack-type unit cell is wound up with a long separating film.

[0006] The electrode is formed by coating an electrode current collector with an electrode slurry, but there has been a problem in that the water remaining in the electrode slurry reduces the performance and life of the battery.

[0007] Therefore, there is an increasing need for an electrode slurry manufacturing apparatus that can measure the amount of water remaining in the electrode slurry in real time to prevent deterioration of the performance and lifespan of the battery. Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above-mentioned problems of the prior art, the present invention provides an apparatus and method for producing electrode slurry, which measures and adjusts the water content or solid content of electrode slurry in real time after the electrode slurry is produced and before the electrode slurry is supplied to a subsequent process. [Means for solving the problem]

[0009] One embodiment of the present invention provides an apparatus for producing electrode slurry, comprising: a mixing section for mixing an electrode active material, a conductive material, a binder, and a solvent to produce electrode slurry; a flow path for sampling the electrode slurry from the mixing section; a weight measuring section for measuring the weight of the electrode slurry sample; a cleaning section for cleaning the inside of the weight measuring section; and an exhaust section for circulating air inside the weight measuring section.

[0010] In one embodiment of the present invention, there is provided an apparatus for producing a slurry for an electrode, wherein the weight measuring unit includes a drying unit that supplies heat to the sample to dry the sample.

[0011] In one embodiment of the present invention, there is provided an apparatus for producing slurry for electrodes, wherein at least one of the flow paths is provided according to the height of the mixing section, and each of the flow paths moves the sample of the slurry for electrodes to the weight measuring section.

[0012] In another embodiment of the present invention, there is provided a method for producing an electrode slurry, the method comprising the steps of: mixing an electrode active material, a conductive material, a binder, and a solvent to produce an electrode slurry; sampling a small amount of the electrode slurry in a weight measuring unit, and then measuring the weight of the sample of the electrode slurry; and removing the electrode slurry sample and then cleaning the weight measuring unit. [Effects of the Invention]

[0013] The electrode slurry producing apparatus and method according to the embodiments of the present invention can control the quality of the electrode slurry and the battery by measuring and adjusting the water content or solid content of the electrode slurry in real time after producing the electrode slurry and before supplying the electrode slurry to a subsequent process. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a conventional electrode slurry production apparatus. [Figure 2] 1 is a side view showing an electrode slurry production apparatus according to an embodiment of the present invention. [Figure 3] FIG. 2 is a cross-sectional view showing a weight measuring unit according to an embodiment of the present invention. [Figure 4] FIG. 10 is a side view showing an electrode slurry producing apparatus according to another embodiment of the present invention. [Explanation of symbols]

[0015] 100 Electrode slurry manufacturing device 10...Mixing section 20 Flow path 30...Weight measurement section 31...Drying section 32 Plate 40 Cleaning section 50 Exhaust section DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described in detail below with reference to the drawings. However, the drawings are for illustrative purposes only and the scope of the present invention is not limited by the drawings.

[0017] FIG. 2 is a side view showing an electrode slurry production apparatus 100 according to one embodiment of the present invention.

[0018] The electrode slurry producing apparatus 100 can include a mixing section 10 , a flow path 20 , a weight measuring section 30 , a cleaning section 40 , and an exhaust section 50 .

[0019] The mixer 10 may prepare an electrode slurry by mixing an electrode active material, a conductive material, a binder, and a solvent. The electrode active material may include either a positive electrode active material or a negative electrode active material, and the positive electrode active material may include lithium ions. The negative electrode active material may reversibly absorb and release lithium ions released from the positive electrode, allowing current to flow through an external circuit. The negative electrode active material may include graphite and silicon.

[0020] The conductive material can increase the conductivity of the electrode active material, and the solvent can adjust the viscosity of the electrode slurry.

[0021] The binder can physically stabilize the electrode and increase the adhesive strength between the electrode active material and the conductive material to the sheet (current collector) to which the electrode slurry is applied in a subsequent process, such as an aluminum sheet or copper sheet.

[0022] As the electrode active material, conductive material, binder, and solvent, various electrode active materials, conductive materials, binders, and solvents used in the art can be used, and the types thereof are not particularly limited.

[0023] The mixing unit 10 may include a main body (not shown) that receives and stores the electrode active material, the conductive material, the binder, and the solvent, and an agitator (not shown) that agitates the electrode active material, the conductive material, the binder, and the solvent.

[0024] The mixing section 10 can be any of various types of mixing devices used in the art, and the type is not particularly limited.

[0025] The flow path 20 can sample the electrode slurry from the mixing section 10. The flow path 20 can be provided penetrating the side of the mixing section 10. The side of the mixing section 10 can mean a surface parallel to the direction of gravity, i.e., all surfaces perpendicular to the upper and lower surfaces of the mixing section 10.

[0026] The flow path 20 can transfer a small amount of the electrode slurry stored in the mixer 10 to the weight measuring unit 30. The flow path 20 can also transfer the electrode slurry sample that has been measured by the weight measuring unit 30 back to the mixer 10. That is, the flow path 20 can be extended from a side of the mixer 10 to the weight measuring unit 30, and at least one flow path 20 can be included.

[0027] The flow path 20 may include one or more of a transfer screw and a pump.

[0028] In one embodiment, when the apparatus 100 for producing electrode slurry according to the present invention is provided with one flow path 20, the flow path 20 can transport the electrode slurry in both directions. Therefore, the transfer screw and pump included in the flow path 20 can transport the electrode slurry in both directions.

[0029] In another embodiment, when the apparatus 100 for producing electrode slurry according to the present invention is provided with two flow paths 20, one flow path 20 can transfer the electrode slurry from the mixing unit 10 to the weight measuring unit 30, and the other flow path 20 can transfer the electrode slurry from the weight measuring unit 30 to the mixing unit 10. In this case, the two flow paths 20 may have the same means for transferring the electrode slurry, such as a transfer screw or a pump, or may have different means, such as a transfer screw-pump or a pump-transfer screw.

[0030] FIG. 3 is a cross-sectional view showing a weight measuring unit 30 according to one embodiment of the present invention.

[0031] The weight measuring unit 30 can measure the weight of the electrode slurry sample. The weight measuring unit 30 places the electrode slurry sample transferred via the flow path 20 on a plate 32 and can measure the weight of the sample.

[0032] The weight measuring unit 30 can measure at least one of the weight of the sample supplied from the flow path 20 and the weight of the sample after drying. Therefore, the weight measuring unit 30 can include a drying unit 31.

[0033] The drying unit 31 can dry the sample by supplying heat to the sample stored in the weight measuring unit 30. The drying unit 31 can dry the sample by increasing the internal temperature of the weight measuring unit 30. In this case, the drying unit 31 can heat the internal temperature of the weight measuring unit 30 to a temperature of 5°C to 300°C, and preferably, the drying unit 31 can heat the internal temperature of the weight measuring unit 30 to a temperature of 20°C to 200°C.

[0034] Alternatively, the drying unit 31 may dry the sample by supplying hot air to the sample stored in the weight measuring unit 30. The drying unit 31 may include a heating unit (not shown) that heats air to produce hot air, and an injection unit (not shown) that injects the hot air into the weight measuring unit 30 and onto the sample.

[0035] The weight measuring unit 30 can calculate the weight of the sample before and after drying as a percentage. Therefore, the weight measuring unit 30 can calculate the ratio of solids and solvent contained in the electrode slurry. Here, the solids can include the electrode active material, conductive material, and binder. In this case, the percentage can be calculated as (weight of sample before drying - weight of sample after drying) / weight of sample before drying x 100.

[0036] The electrode slurry produced by the electrode slurry production apparatus 100 according to the present invention may have a weight percentage of 10% to 90% before and after drying, and preferably, the weight percentage of the electrode slurry before and after drying may be 20% to 80%. If the weight percentage of the electrode slurry before and after drying is less than 10%, the proportion of solids contained in the electrode slurry is high, which may make it difficult to control when applying the electrode slurry to a conductor in a subsequent process. If the weight percentage of the electrode slurry before and after drying is more than 90%, the proportion of solvent contained in the electrode slurry is high, which may make it difficult to produce a high-performance electrode.

[0037] The electrode slurry producing apparatus 100 may include a display unit (not shown). The display unit may display one or more of the weight and percentage of the sample before and after drying measured and calculated by the weight measuring unit 30. The display unit may be a display device that visually displays data used in the art, and is not particularly limited. For example, the display unit may include an LCD, an LED, a touch screen, etc.

[0038] The electrode slurry producing apparatus 100 may include at least one of an input unit (not shown) and a control unit (not shown).

[0039] The input unit allows a user to arbitrarily input the supply amounts of the electrode active material, conductive material, binder, and solvent, and the mixing speed of the mixer 10. When the display unit according to the present invention is provided as a touch screen, the display unit can also function as the input unit.

[0040] The control unit receives data on one or more of the weight of the sample before drying, the weight of the sample after drying, and the percentage of the sample weight from the weight measuring unit 30, and can automatically adjust the supply amounts of the electrode active material, conductive material, binder, and solvent and the mixing speed of the mixing unit 10.

[0041] The control unit may store one or more reference values ​​of the weight of the sample before drying, the weight of the sample after drying, and the percentage of the weight of the sample. The control unit may compare the data transmitted from the weight measuring unit 30 with the stored reference values ​​to control the supply amounts of the electrode active material, conductive material, binder, and solvent and the mixing speed of the mixer 10.

[0042] For example, the control unit stores a reference value of a sample weight percentage of 40% to 80%, and if the sample weight percentage measured and calculated by the weight measurement unit 30 is 20%, the control unit can increase the amount of solvent supplied.

[0043] FIG. 4 is a side view showing an electrode slurry production apparatus 100 according to another embodiment of the present invention.

[0044] The apparatus 100 for producing slurry for an electrode may be provided with a plurality of flow paths 20 according to the height of the mixer 10. The apparatus 100 for producing slurry for an electrode may be provided with a plurality of stacked weight measuring units 30. The apparatus 100 for producing slurry for an electrode may be provided with a corresponding number of flow paths 20 and weight measuring units 30, and each of the plurality of flow paths 20 may be connected to one weight measuring unit 30. That is, the flow paths 20 may extract a slurry sample for an electrode according to the height of the mixer 10, and the weight measuring units 30 may measure the weight of the slurry for an electrode according to the height of each mixer 10.

[0045] In this case, if there is a deviation in the weight of the sample before drying, the weight of the sample after drying, and the percentage of the sample weight measured by the multiple weight measuring units 30, the control unit can determine that the mixing of the electrode slurry is not uniform depending on the height of the mixing unit 10 and control the mixing speed of the mixing unit 10.

[0046] The cleaning unit 40 can clean the inside of the weight measuring unit 30. The cleaning unit 40 can spray a cleaning liquid and air into the weight measuring unit 30 to clean it. The cleaning unit 40 can spray the cleaning liquid and air at high pressure to wash away solids remaining in the weight measuring unit 30. The cleaning liquid sprayed from the cleaning unit 40 can contain the same material as the solvent contained in the electrode slurry.

[0047] The cleaning unit 40 may include a moving pipe (not shown) that receives a supply of cleaning liquid or air to move the cleaning unit 40, and a spray nozzle (not shown) that receives a supply of cleaning liquid or air from the moving pipe and sprays the cleaning liquid onto one or more of the weight measuring unit 30 and the plate. One or more spray nozzles may be included, and may be connected to and penetrate the outer surface of the moving pipe.

[0048] When the cleaning unit 40 cleans the weighing unit 30 or the plate using a cleaning liquid, the cleaning unit 40 may further include an air supply unit (not shown). The air supply unit may supply air to the transfer pipe so that high-pressure liquid is sprayed from the spray nozzle.

[0049] In the apparatus 100 for producing electrode slurry according to the present invention, the cleaning unit 40 may further include a hot air dryer (not shown) to reduce errors when the weight measuring unit 30 measures the weight of the solid content. The hot air dryer may supply heated air to the weight measuring unit 30 to evaporate the liquid.

[0050] The electrode slurry producing apparatus 100 according to the present invention may further include a plate storage unit (not shown).

[0051] The plate storage unit can store a plurality of plates, is located on one side of the weighing unit 30, and can supply or replace plates inside the weighing unit 30. Therefore, the plate storage unit and the weighing unit 30 can include a through-hole on one side to allow plates to be moved. The through-holes provided in the plate storage unit and the weighing unit 30 can correspond in size and position.

[0052] The through-hole may include an opening / closing unit, which may be linked to the cleaning unit 40. Therefore, the opening / closing unit is closed when the weight measuring unit 30 measures the weight of the electrode slurry sample, and after the weight measurement is completed, the cleaning unit 40 cleans the inside of the weight measuring unit 30, or the opening / closing unit is opened before or after cleaning to replace the plate.

[0053] The exhaust unit 50 can circulate air inside the weighing unit 30. The exhaust unit 50 can discharge high-pressure air sprayed from the cleaning unit 40 to the outside or discharge air heated by the hot air drying unit to the outside, thereby reducing the temperature inside the weighing unit 30. The exhaust unit 50 can also discharge residual solids washed off by the cleaning unit 40 to the outside.

[0054] In one embodiment, the exhaust unit 50 may be coupled to one surface of the weight measuring unit 30 in the form of a hollow tube, and may include a blower fan (not shown) that exhausts the air inside the weight measuring unit 30 to the outside.

[0055] When the apparatus 100 for producing slurry for an electrode according to the present invention includes a plurality of weight measuring units 30, the exhaust unit 50 may be provided for each of the weight measuring units 30.

[0056] The apparatus 100 for producing electrode slurry according to the present invention may further include an opening / closing unit (not shown) between the weight measuring unit 30 and the exhaust unit 50. The opening / closing unit is closed when the weight measuring unit 30 measures the weight of the electrode slurry or the solid content, thereby preventing air inside the weight measuring unit 30 from being exhausted to the outside. After the cleaning unit 40 cleans the weight measuring unit 30 or the plate, the opening / closing unit is opened, allowing air to be exhausted to the outside. The opening / closing unit may be controlled by a control unit.

[0057] A method for producing electrode slurry according to one embodiment of the present invention may include a step of producing electrode slurry (S10), a step of measuring the weight of the electrode slurry sample (S20), and a step of cleaning the weight measurement unit (S30).

[0058] In the step (S10) of preparing a slurry for an electrode, an electrode active material, a conductive material, a binder, and a solvent may be mixed to prepare the slurry for an electrode.

[0059] The conductive material is not particularly limited as long as it does not induce chemical changes in the battery and is conductive, and typical examples include a single material or a mixture of two or more materials selected from the group consisting of natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon fiber, metal fiber, carbon fluoride, aluminum, nickel powder, zinc oxide, potassium titanate, titanium oxide, and polyphenylene derivatives.

[0060] As the binder, various binder polymers can be used, such as polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene butadiene rubber (SBR), fluororubber, polyacrylic acid, and polymers in which the hydrogen of these is substituted with Li, Na, Ca, or the like, or various copolymers.

[0061] The solvent can include any one of NMP (N-Methyl Pyrrolidone), DMI (Dimethyl Isosorbide), and DMSO (Dimethyl Sulfoxide).

[0062] The step of measuring the weight of the electrode slurry sample (S20) may involve sampling the electrode slurry in a weight measuring unit and measuring the weight of the sampled electrode slurry sample.

[0063] The step of measuring the weight of the electrode slurry sample (S20) may include a step of measuring the weight of the electrode slurry after sampling (S21) and a step of measuring the weight of the sampled electrode slurry after drying (S22). The step of measuring the weight of the electrode slurry sample (S20) may measure the amount of electrode active material contained in the electrode slurry to inspect the quality of the electrode slurry.

[0064] That is, in the step of measuring the weight of the electrode slurry sample (S20), the weight of the electrode slurry sample before and after drying is measured, and it is possible to calculate whether the electrode active material in the electrode slurry is contained in an amount equal to or greater than the previously stored reference value.

[0065] For example, in the step (S20) of measuring the weight of the electrode slurry sample, the weight of the electrode slurry sample before and after drying is measured, and if the electrode active material in the electrode slurry is calculated to be less than 95 wt %, the amount of electrode binder or solvent supplied to the mixing section can be reduced or the amount of electrode active material supplied can be increased.

[0066] In the step of cleaning the weight measuring unit (S30), the weight measuring unit may be cleaned after removing the electrode slurry sample for which the measurement has been completed.

[0067] At this time, the electrode slurry sample can be discharged and discarded, or can be resupplied to the mixing section via the flow path.

[0068] The step of cleaning the weighing unit (S30) may include the steps of spraying one or more of a cleaning liquid and air onto the inner wall of the weighing unit (S31) and discharging one or more of the cleaning liquid and air that have cleaned the inner wall of the weighing unit to the outside (S32). In this case, the cleaning liquid and air may be sprayed at high pressure.

[0069] When a cleaning liquid is used in the step (S30) of cleaning the weight measuring unit, the step (S30) of cleaning the weight measuring unit may include a step (S31-1) of drying the inside of the weight measuring unit and a step (S32-1) of exhausting the evaporated cleaning liquid to the outside.

[0070] In addition, when air is sprayed to wash the residual electrode slurry in the weight measuring unit in the step (S30) of cleaning the weight measuring unit, the method may include a step (S32-2) of discharging the air used for cleaning and the residual electrode slurry desorbed by the air to the outside of the weight measuring unit.

[0071] The step of cleaning the weighing unit (S30) may involve spraying one or more of a cleaning solution and air onto a plate included in the weighing unit on which the electrode slurry sample is placed to clean the weighing unit, or by replacing the plate.

[0072] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that the present invention can be modified and changed in various ways without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. a mixing section for mixing an electrode active material, a conductive material, a binder, and a solvent to produce an electrode slurry; a flow path for sampling the electrode slurry from the mixing section; a weight measuring unit for measuring the weight of a sample of the electrode slurry; a cleaning unit that cleans the inside of the weight measuring unit; an exhaust unit that circulates air inside the weight measuring unit; and a control unit that stores a reference value for the weight of the sample of the electrode slurry, and adjusts one or more of the supply amount of the electrode active material, the conductive material, the binder, and the solvent supplied to the mixer and the mixing speed of the mixer when the weight of the sample measured by the weight measuring unit is less than the reference value; Including, the weight measuring unit includes a drying unit that supplies heat to the sample to dry the sample; the weight measuring unit measures the weight of the sample before and after drying, a plurality of the flow paths are provided according to the height of the mixing section, and each of the flow paths moves the sample of the electrode slurry to the weight measuring section; The apparatus for producing electrode slurry, wherein the reference value is at least one of the weight of the sample before drying, the weight of the sample after drying, and a percentage of the sample weight.

2. 2. The electrode slurry producing apparatus according to claim 1, wherein the weight measuring unit includes a plate on which the sample is placed.

3. 3. The apparatus for producing electrode slurry according to claim 2, further comprising a plate storage unit located on one side of the weight measuring unit, storing a plurality of the plates, and supplying and replacing the plates to the weight measuring unit.

4. 2. The apparatus for producing electrode slurry according to claim 1, further comprising a display unit that displays at least one of a weight of the sample before drying, a weight of the sample after drying, and a percentage of the weight of the sample before and after drying.

5. The apparatus for producing electrode slurry according to claim 1 , wherein the weight measuring unit is one or more and is stacked, and measures the weight of the sample of the electrode slurry supplied from each of the flow paths.

6. The apparatus for producing electrode slurry according to claim 1 , wherein the flow path moves the electrode slurry to the weight measuring unit by one of a transfer screw and a pump.

7. 2. The apparatus for producing electrode slurry according to claim 1, wherein the cleaning unit cleans the weight measuring unit by injecting at least one of a cleaning liquid and air into the inside of the weight measuring unit.

8. 8. The electrode slurry producing apparatus according to claim 7, further comprising a hot air drying unit that supplies heated air to the weight measuring unit to evaporate the cleaning liquid.

9. A step of mixing an electrode active material, a conductive material, a binder, and a solvent using a mixing unit to prepare an electrode slurry; a step of sampling a small amount of the electrode slurry in a weight measuring unit, supplying heat to the sampled slurry to dry the electrode slurry sample, and then measuring the weights of the sampled electrode slurry before and after drying; and cleaning the weight measuring unit after removing the sample of electrode slurry. and The measuring step includes measuring the weight of the sample of the electrode slurry before and after drying, calculating whether the electrode active material in the electrode slurry is contained in an amount equal to or greater than a reference value, and adjusting, if the weight of the sample measured by the weight measuring unit is less than the reference value, one or more of the supply amount of the electrode active material, the conductive material, the binder, and the solvent supplied to the mixing unit and one or more of the mixing speed of the mixing unit; The cleaning step includes spraying at least one of a cleaning liquid and air onto the inner wall of the weight measuring unit; and and discharging to the outside at least one of the cleaning liquid and air used to clean the inner wall of the weight measuring unit, In the sampling, the electrode slurry is moved from a mixing section that mixes the electrode active material, the conductive material, the binder, and the solvent to produce the electrode slurry to the weight measuring section through a plurality of flow paths that are provided according to the height of the mixing section.

10. 10. The method of claim 9, wherein the washing step includes spraying at least one of a washing liquid and air onto a plate included in the weight measuring unit on which the sample of the electrode slurry is placed.

11. 10. The method for producing electrode slurry according to claim 9, wherein the cleaning step includes the step of replacing a plate that is included in the weight measuring unit and on which the sample of the electrode slurry is placed.

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