JP6843374B2 - Kneading method for producing battery electrode slurry - Google Patents

Description

The present invention relates to a kneading method for producing a battery electrode slurry.

Conventionally, batch kneading is generally used as a method of kneading a plurality of materials to obtain a slurry. Batch kneading is to put all the plurality of materials necessary for preparing the slurry into a cauldron and knead them until the plurality of materials are uniformly mixed.

However, in batch kneading, it is necessary to take a long kneading time because a plurality of materials are put together at once and then mixed uniformly. In addition, it is necessary to manually perform cleaning work such as replacement of the cauldron, a blade for kneading, and scraping work inside the cauldron. In addition, the cleaning work described above is required each time the cauldron is replaced. From the above, batch kneading has been a cause of an increase in man-hours in the process of producing a slurry.

Further, in batch kneading, it takes time from when all the plurality of materials are put into the cauldron until the slurry is obtained. Therefore, in order to obtain a certain amount of slurry in a short time, it is necessary to increase the amount of slurry obtained by one batch kneading, and it is necessary to increase the size of the cauldron. Therefore, it has been difficult to miniaturize the device.

Further, in batch kneading, since there are steps that need to be performed manually such as cauldron replacement and cleaning work as described above, it is difficult to completely automate the slurry preparation step.

Further, in batch kneading, the degree of freedom in the amount of slurry to be produced is low, and a large amount of slurry is produced so as not to run short, so that there may be a problem of a time lag until a large amount of obtained slurry is used.

Therefore, a pre-kneading section for coarsely kneading a plurality of materials and a main kneading section for main kneading the materials roughly kneaded in the pre-kneading section are provided, and the materials roughly kneaded in the pre-kneading section are main-kneaded by a mono pump. A kneading device for supplying to the unit has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-333924

When forming an electrode plate (for example, a positive electrode plate) constituting a battery electrode (for example, a positive electrode) of a secondary battery, a battery electrode slurry obtained by kneading necessary materials is used as a metal sheet (for example, an aluminum sheet for a positive electrode). An electrode plate is formed by applying it on top and drying it. This battery electrode slurry contains a binder. Binders are used to bond the electrode active materials and to bond the electrode active materials to the metal sheet. When the temperature of the battery electrode slurry fluctuates due to the kneading process, changes such as hardening of the binder occur in the battery electrode slurry, and the quality of the battery electrode slurry becomes unstable. Since the kneading apparatus shown in Patent Document 1 does not consider the fluctuation of the temperature of the battery electrode slurry due to the kneading process, the quality of the battery electrode slurry may not be stable.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to keep the quality of the battery electrode slurry stable.

The present invention proposes the following items in order to solve the above-mentioned problems. In addition, in order to facilitate understanding, the description will be given with reference numerals corresponding to the embodiments of the present invention, but the present invention is not limited thereto.

(1) In the present invention, a battery electrode slurry for producing a battery electrode slurry is produced by urging, transporting and kneading a material for producing a battery electrode slurry containing a binder (for example, corresponding to a positive electrode slurry described later). A kneading method for production, wherein a plurality of materials for producing the battery electrode slurry (for example, corresponding to a binder, a positive electrode active material, and a conductive auxiliary agent described later) are supplied, and the supplied plurality of materials are kneaded. In the first step of continuously discharging, the second step of transporting the material discharged in the first step, the material kneaded in the first step, and the second step. The material being transported and the material supplied for kneading in the first step based on the measurement results in the third step of measuring the temperature of at least one of the three steps and the third step. The temperature of at least one of the material kneaded in the first step and the material transported in the second step is controlled to be lower than the curing temperature of the binder. We propose a kneading method for producing a battery electrode slurry, which comprises 4 steps.

According to the present invention, the supplied plurality of materials are kneaded by the first step, and the kneaded materials are transported by the second step. Therefore, according to the first step and the second step, it is possible to accept the plurality of materials and transfer the kneaded materials while kneading the plurality of materials. That is, according to the first step and the second step, the transfer of the kneaded material and the kneading of the plurality of newly supplied materials can be performed in parallel. Therefore, the material can be continuously supplied to the subsequent stage of the configuration in which the second step is performed.

Further, since the material can be continuously supplied to the subsequent stage of the configuration in which the second step is performed as described above, it is not necessary to replace the cauldron as in the conventional case, and the temperature control of the battery electrode slurry in the present invention is eliminated. Can be easily performed.

Further, as described above, since the material can be continuously supplied to the subsequent stage of the configuration in which the second step is performed, it is not necessary to knead a large amount of material at once. Therefore, since a large amount of battery electrode slurry is not produced at one time, it is possible to prevent the temperature of the battery electrode slurry from fluctuating in the large amount of battery electrode slurry produced at one time. Therefore, it is possible to produce a battery electrode slurry having stable quality.

Further, in the first step, the temperature of the material rises because the material is mixed while applying energy. If the temperature rise of this material becomes too large, the binder contained in the material may be cured. When the material is cured, not only the battery electrode slurry having the desired quality cannot be produced, but also the battery electrode slurry is clogged inside the device for carrying out the kneading method for producing the battery electrode slurry, and the kneading for producing the battery electrode slurry is performed. It can also lead to failure of the equipment that implements the method.

Therefore, in the third step, it was decided to measure the temperature of at least one of the material kneaded in the first step and the material transported in the second step. Further, according to the fourth step, based on the measurement result in the third step, the material supplied for kneading in the first step, the material kneaded in the first step, and the second step. It was decided to control the temperature of at least one of the materials being transported in the above so as to be lower than the curing temperature of the binder. Therefore, it is possible to prevent the temperature of the material from becoming higher than the curing temperature of the binder, so that it is possible to prevent a failure of the apparatus for carrying out the kneading method for producing the battery electrode slurry, and it is possible to prevent the battery electrode slurry from being damaged. The quality can be stabilized.

(2) The present invention supplies the kneading method for producing a battery electrode slurry of (1) for kneading in the first step based on the measurement results in the third step in the fourth step. The temperature of at least one of the material to be prepared, the material kneaded in the first step, and the material transported in the second step is lower than the curing temperature of the binder and The present invention proposes a kneading method for producing a battery electrode slurry, which comprises controlling the viscosity of the material to a temperature higher than a temperature exceeding a predetermined permissible value.

Here, when the temperature drops extremely, the viscosity of the material becomes high, and even if the same energy as usual is applied to the material in the first step, the shearing force and frictional force applied to the material are increased. Since it changes so much, it may not be possible to obtain a battery electrode slurry having a desired quality. Therefore, according to the present invention, in the kneading method for producing a battery electrode slurry of (1), the material supplied for kneading in the first step, the material kneaded in the first step, and the second. It was decided to control the temperature of at least one of the materials transported in the step of the above step to a temperature lower than the curing temperature of the binder and higher than the temperature at which the viscosity of the material exceeds a predetermined allowable value. .. Therefore, not only the hardening of the material due to the temperature rise but also the increase in the viscosity of the material due to the temperature drop can be suppressed, so that the quality of the battery electrode slurry can be improved more accurately.

(3) In the present invention, a battery electrode slurry for producing a battery electrode slurry is produced by urging, transporting and kneading a material for producing a battery electrode slurry containing a binder (for example, corresponding to a positive electrode slurry described later). A kneading method for production, wherein a plurality of materials for producing the battery electrode slurry (for example, corresponding to a binder, a positive electrode active material, and a conductive auxiliary agent described later) are supplied, and the supplied plurality of materials are kneaded. The first step of continuously discharging, the second step of transporting the material discharged in the first step, and the material transported in the second step are stored and stored. A third step of continuously discharging the material, a material kneaded in the first step, a material transported in the second step, and a material stored in the third step. The fourth step of measuring the temperature of at least one of the above, the material supplied for kneading in the first step based on the measurement result in the fourth step, and the first. At least one of the temperature of the material kneaded in the step, the material transported in the second step, and the material stored in the third step is the curing temperature of the binder. We propose a kneading method for producing a battery electrode slurry, which comprises a fifth step of controlling the temperature to be lower.

According to the present invention, according to the third step, the material transported in the second step is stored and the stored material is continuously discharged. Therefore, the material kneaded and continuously discharged in the first step is stored in the third step. Therefore, since the materials kneaded in the first step are mixed while being stored in the third step, there is a variation in the quality of the materials at the time of being supplied to the subsequent stage of the configuration in which the third step is performed. , Compared to the variation in material quality at the time of discharge from the configuration in which the first step is performed. Therefore, in addition to the above-mentioned effect that can be achieved by the kneading method for producing the battery electrode slurry (1), the effect that the quality of the battery electrode slurry can be further stabilized can also be exhibited.

(4) The present invention supplies the kneading method for producing a battery electrode slurry of (3) for kneading in the first step based on the measurement results in the fourth step in the fifth step. At least one of the material to be prepared, the material kneaded in the first step, the material transported in the second step, and the material stored in the third step. We propose a kneading method for producing a battery electrode slurry, which comprises controlling one temperature to a temperature lower than the curing temperature of the binder and higher than a temperature at which the viscosity of the material exceeds a predetermined allowable value. ..

According to the present invention, in the kneading method for producing a battery electrode slurry of (3), the material supplied for kneading in the first step, the material kneaded in the first step, and the second step. At least one of the temperature of the material transported in the above and the material stored in the third step is lower than the curing temperature of the binder, and the viscosity of the material exceeds a predetermined allowable value. It was decided to control the temperature to a higher temperature. Therefore, not only the hardening of the material due to the temperature rise but also the increase in the viscosity of the material due to the temperature drop can be suppressed, so that the quality of the battery electrode slurry can be more accurately stabilized.

(5) In the present invention, in the kneading method for producing a battery electrode slurry according to (1) or (2), the space where the first step is performed and the space where the second step is performed communicate with each other. We propose a kneading method for producing a battery electrode slurry, which comprises a fifth step of forming a closed space and making the space decompressed or filled with an inert gas.

According to the present invention, in the kneading method for producing a battery electrode slurry of (1) or (2), the space where the first step is performed and the space where the second step is performed are communicated and closed. I decided to form a space. In addition, it was decided that this space should be decompressed or filled with an inert gas. Therefore, the material and the battery electrode slurry are exposed to the atmosphere between the time when the material is put into the space where the first step is performed and the time when the battery electrode slurry is discharged from the space where the second step is performed. It can be suppressed. Therefore, the quality of the battery electrode slurry can be further stabilized.

(6) In the present invention, regarding the kneading method for producing a battery electrode slurry according to (3) or (4), the space where the first step is performed, the space where the second step is performed, and the third step. For producing a battery electrode slurry, which comprises a sixth step of forming a closed space by communicating with a space in which the steps are performed, and making the space decompressed or filled with an inert gas. We are proposing a kneading method.

According to the present invention, in the kneading method for producing a battery electrode slurry according to (3) or (4), a space where the first step is performed, a space where the second step is performed, and a third step are performed. It was decided to form a closed space by communicating with the space. In addition, it was decided that this space should be decompressed or filled with an inert gas. Therefore, the material and the battery electrode slurry are exposed to the atmosphere between the time when the material is put into the space where the first step is performed and the time when the battery electrode slurry is discharged from the space where the third step is performed. It can be suppressed. Therefore, the quality of the battery electrode slurry can be further stabilized.

According to the present invention, the battery electrode slurry can be continuously obtained in a short time while maintaining the stable quality of the battery electrode slurry.

It is a block diagram which shows the outline of the kneading apparatus for making a battery electrode slurry which concerns on 1st Embodiment of this invention. It is a block diagram which shows the outline of the kneading apparatus for making a battery electrode slurry which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the outline of the tank provided in the kneading apparatus for making a battery electrode slurry which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the outline of the kneading apparatus for making a battery electrode slurry which concerns on 3rd Embodiment of this invention. It is a figure which shows the example which provided a plurality of kneading portions in parallel which concerns on 1st Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The components in the following embodiments can be replaced with existing components as appropriate, and various variations including combinations with other existing components are possible. Therefore, the description of the following embodiments does not limit the content of the invention described in the claims.

<First Embodiment>
FIG. 1 is a configuration diagram showing an outline of a battery electrode slurry manufacturing kneading device 1 capable of realizing the battery electrode slurry manufacturing kneading method according to the first embodiment of the present invention. The kneading device 1 for producing a battery electrode slurry kneads a binder, a positive electrode active material, and a conductive auxiliary agent (conductive auxiliary material) as a plurality of materials to produce a positive electrode slurry used for a positive electrode of a lithium ion secondary battery. This is a kneading device for producing a slurry.

The binder is housed in the binder supply unit 11. A pipe 21 communicates with the binder supply unit 11, and the binder supply unit 11 continuously supplies the binder to the pipe 21. The kneading portion 14 communicates with the pipe 21, and a mono pump 51 is provided. The mono pump 51 urges the binder supplied to the pipe 21 toward the kneading section 14.

Note that the continuous described above, in this embodiment, it is meant that no (endlessly) temporally interrupted it. Thus, a continuously supplying binder to the pipe 21 is that supplying without (endlessly) binder pipe 21 temporally interrupted it.

Further, as the binder, an organic solvent-based (non-aqueous) binder such as polyvinylidene fluoride (PVdF) or polytetrafluoroethylene (PTFE), which is used by dissolving it in an organic solvent, can be used. Further, as an aqueous binder, styrene-butadiene rubber (SBR) that can be dispersed in water, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylonitrile, and hydroxyethyl (meth) acrylate. Ethylene unsaturated carboxylic acid esters such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid and other ethylenically unsaturated carboxylic acids, and not only used in combination with SBR, but also attracting attention as a binder in recent years. It is also possible to use an aqueous polymer such as carboxymethyl cellulose (CMC), an alginate compound, or the like. Further, a mixture of a plurality of types thereof can also be used.

Further, the binder can be used by being dissolved or dispersed in a solvent. As the solvent, N-methylpyrrolidone, dimethylformamide, isopropanol, toluene, water and the like can be used, and a mixture of a plurality of these can also be used. These can be appropriately selected and used according to the type and characteristics of the thickener and the active material to be used.

The positive electrode active material is housed in the positive electrode material supply unit 12. A pipe 22 communicates with the positive electrode material supply unit 12, and the positive electrode material supply unit 12 continuously supplies the positive electrode active material to the pipe 22. The kneading portion 14 communicates with the pipe 22, and a weight scale 53 is provided. The weighing scale 53 measures the weight of the positive electrode active material flowing inside the pipe 22 from the positive electrode material supply unit 12 toward the kneading unit 14, and measures the instantaneous supply amount of the positive electrode active material supplied to the pipe 22. , The measurement result is transmitted to the control unit 32. The positive electrode material supply unit 12 is provided with a feeder (not shown) that supplies the charged positive electrode active material to the pipe 22, and the control unit 32 confirms whether or not there is a change in the instantaneous supply amount and the integrated supply amount. The supply amount is determined based on the measurement result transmitted from the weighing scale 53, and the determined supply amount is transmitted to the feeder of the positive electrode material supply unit 12. The feeder of the positive electrode material supply unit 12 continuously supplies the positive electrode active material to the pipe 22 based on the supply amount transmitted from the control unit 32. The pipe 22 extends in the vertical direction, and the kneading portion 14 communicates with the lower end of the pipe 22. Therefore, the positive electrode active material supplied to the pipe 22 freely falls due to gravity and is continuously supplied to the kneading portion 14.

The positive electrode active material is Li _x MO ₂ (M is one or more elements selected from Ni, Co, Fe, Mn, Si, and Al, and x is 0 <x <1. A substance having a layered structure / spinel structure such as (which satisfies 5), _{or one or more metal elements selected from the general formula Li x} APO ₄ (A is Ti, Zn, Mg, Co, Mn). Yes, x can satisfy a substance having an olivine type structure such as 0 <x ≦ 1.2). _{In particular, the general formula Li x} F _{y A (1-y)} PO ₄ , which is a substance having olivine-type lithium iron phosphate (where x satisfies 0 <x ≦ 1 and y satisfies 0 <y ≦ 1). , A is a kind of metal element selected from Ti, Zn, Mg, Co, and Mn)). Further, particles in which the surface of the lithium metal phosphate compound is coated with carbon, or aggregates of these particles can also be used.

The conductive auxiliary agent is housed in the conductive auxiliary agent supply unit 13. A pipe 23 communicates with the conductive auxiliary agent supply unit 13, and the conductive auxiliary agent supply unit 13 continuously supplies the conductive auxiliary agent to the pipe 23. The kneading portion 14 communicates with the pipe 23, and a weight scale 54 is provided. The weighing scale 54 measures the weight of the conductive auxiliary agent flowing inside the pipe 23 from the conductive auxiliary agent supply unit 13 toward the kneading unit 14, and measures the instantaneous supply amount of the conductive auxiliary agent supplied to the pipe 23. Then, the measurement result is transmitted to the control unit 32. The conductive auxiliary agent supply unit 13 is provided with a feeder (not shown) that supplies the charged conductive auxiliary agent to the pipe 23, and the control unit 32 confirms whether or not there is a change in the instantaneous supply amount and integrates the supply. The amount is controlled, the supply amount is determined based on the measurement result transmitted from the weighing scale 54, and the determined supply amount is transmitted to the feeder of the conductive auxiliary agent supply unit 13. The feeder of the conductive auxiliary agent supply unit 13 continuously supplies the conductive auxiliary agent to the pipe 23 based on the supply amount transmitted from the control unit 32. The pipe 23 extends in the vertical direction, and the kneading portion 14 communicates with the lower end of the pipe 23. Therefore, the conductive auxiliary agent supplied to the pipe 23 freely falls due to gravity and is continuously supplied to the kneading portion 14.

As the conductive auxiliary agent, carbon powder such as acetylene black, furnace black, or carbon black can be used. Further, a mixture of a plurality of types thereof can also be used.

From the above, the binder urged by the MONO pump 51 is continuously supplied to the kneading section 14 in an appropriate amount, and the positive electrode active material and the conductive auxiliary agent are continuously dropped in an appropriate amount by gravity. Will be supplied.

The kneading unit 14 sequentially kneads the continuously supplied binder, positive electrode active material, and conductive auxiliary agent, and continuously discharges them as a positive electrode slurry. A coater 19 communicates with the kneading section 14 via the pipe 24 and the filter 18, and the positive electrode slurry continuously discharged from the kneading section 14 is urged from the mono pump 51 to the binder and from the kneading section 14. Is continuously supplied to the coater 19 via the pipe 24 and the filter 18 by the discharge force of the above.

According to the above, the kneading unit 14 continuously accepts these materials and continuously supplies the positive electrode slurry to the coater 19 while kneading the binder, the positive electrode active material, and the conductive auxiliary agent. .. That is, the kneading unit 14 continuously supplies the positive electrode slurry to the coater 19 and continuously kneads the newly supplied material in parallel.

If the temperature of the positive electrode slurry is lowered too much, the viscosity of the positive electrode slurry becomes too high. On the other hand, if the temperature of the positive electrode slurry rises too much, deterioration such as fibrillation (curing) and separation occurs in the binder.

Therefore, as shown in FIG. 1, the pipe 24 is provided with a temperature sensor 61. The temperature sensor 61 measures the temperature of the positive electrode slurry discharged from the kneading unit 14, and transmits the measurement result to the temperature control unit 71.

The temperature control unit 71 sets the temperature of the material kneaded in the kneading unit 14 lower than the curing temperature of the binder and the viscosity of the positive electrode slurry is predetermined according to the temperature of the positive electrode slurry measured by the temperature sensor 61. Control the temperature higher than the allowable value. Specifically, the temperature control unit 71 includes a temperature control jacket that surrounds the kneading unit 14. Cooling water and hot water can be circulated in the temperature control jacket, and the kneading section 14 is cooled or heated by flowing the cooling water or hot water into the temperature control jacket to cool or heat the kneading section 14, and the temperature of the positive electrode slurry in the kneading section 14 is reached. Can be adjusted to the desired temperature.

If the distance from the kneading portion 14 to the coater 19 is long, the length of the pipe 24 becomes long, and the temperature of the positive electrode slurry flowing inside the pipe 24 may easily change. Therefore, in this case, a jacket for cooling and a jacket for heating are attached to the pipe 24, the temperature of the positive electrode slurry flowing inside the pipe 24 is lower than the curing temperature of the binder, and the viscosity of the positive electrode slurry is predetermined. It is preferable that the temperature is higher than the allowable value of.

The filter 18 removes impurities contained in the positive electrode slurry that flows inside the pipe 24 from the kneading portion 14 toward the coater 19. Impurities removed by the filter 18 include bubbles and undispersed agglomerates.

The coater 19 applies the positive electrode slurry from which impurities have been removed by the filter 18 to the current collector. As the current collector, any one having electrical conductivity such as a metal foil can be used, and the material, shape and size are not particularly limited. Preferably, it is desirable to use aluminum foil or copper foil.

The binder supply unit 11, the positive electrode material supply unit 12, and the conductive auxiliary agent supply unit 13 are each the initial end, and the coater 19 is the end, and the space formed by communicating these is sealed. A space control unit 31 communicates with the space. The space control unit 31 puts the above-mentioned space in a state of being decompressed or filled with an inert gas. As the inert gas, for example, nitrogen can be used.

The above kneading method for producing a battery electrode slurry can produce the following effects.

In the kneading method for producing a battery electrode slurry in the present embodiment, the binder is supplied to the kneading section 14 by the binder supply section 11 and the pipe 21, the positive electrode active material is supplied by the positive electrode material supply section 12 and the pipe 22, and the conductive auxiliary agent is supplied. The conductive auxiliary agent is supplied by the supply unit 13 and the pipe 23, the plurality of supplied materials are kneaded by the kneading unit 14, and the kneaded positive electrode slurry is supplied to the coater 19 by the pipe 24. Therefore, the kneading unit 14 can accept the plurality of materials and supply the kneaded materials to the coater 19 while kneading the plurality of materials. That is, the kneading unit 14 can supply the kneaded material to the coater 19 and knead a plurality of newly supplied materials in parallel. Therefore, the material can be continuously supplied to the coater 19.

Further, in the kneading method for producing the battery electrode slurry in the present embodiment, since the positive electrode slurry can be continuously supplied to the coater 19 as described above, it is not necessary to replace the cauldron as in the conventional case, so that the battery The temperature of the positive electrode slurry in the electrode slurry-making kneading device 1 can be easily controlled.

Further, in the kneading method for producing the battery electrode slurry in the present embodiment, since the positive electrode slurry can be continuously supplied to the coater 19 as described above, it is not necessary to knead a large amount of materials at once. Therefore, since a large amount of positive electrode slurry is not produced at one time, it is possible to prevent the temperature of the positive electrode slurry from fluctuating in the large amount of positive electrode slurry produced at one time. Therefore, it is possible to produce a positive electrode slurry having stable quality.

Further, in the kneading method for producing a battery electrode slurry in the present embodiment, the temperature of the positive electrode slurry discharged from the kneading section 14 is measured by the temperature sensor 61, and the material kneaded in the kneading section 14 by the temperature control section 71. The temperature of the binder is controlled to be lower than the curing temperature of the binder. Therefore, it is possible to prevent the temperature of the positive electrode slurry from becoming higher than the curing temperature of the binder. Therefore, it is possible to prevent the failure of the kneading device 1 for producing the battery electrode slurry and further stabilize the quality of the positive electrode slurry.

Further, in the kneading method for producing a battery electrode slurry in the present embodiment, the temperature of the material kneaded in the kneading unit 14 is lower than the curing temperature of the binder by the temperature control unit 71, and the viscosity of the positive electrode slurry is predetermined. Control the temperature higher than the allowable value. Therefore, it is possible to suppress the hardening of the positive electrode slurry due to the temperature rise and the increase in the viscosity of the positive electrode slurry due to the temperature decrease, so that the quality of the positive electrode slurry can be further stabilized.

Further, in the kneading method for producing the battery electrode slurry in the present embodiment, the binder transported by the pipe 21 is urged by the MONO pump 51, and the positive electrode slurry is discharged from the kneading portion 14. Therefore, due to the urging force of the MONO pump 51 and the discharge force from the kneading unit 14, the materials and discharges in each configuration provided in the battery electrode slurry manufacturing kneading device 1 are moved into the battery electrode slurry manufacturing kneading device 1. It will be transferred. Therefore, no manpower is required to prepare the positive electrode slurry, and the entire kneading process can be automated.

Further, in the kneading method for producing a battery electrode slurry in the present embodiment, the kneading unit 14 sequentially kneads the continuously supplied binder, positive electrode active material, and conductive auxiliary agent and continuously discharges them as a positive electrode slurry. To do. Further, the processing amount of the kneading unit 14 per unit time is equal to the total amount of the plurality of materials supplied to the kneading unit 14 per unit time. Therefore, the total amount of the plurality of materials supplied to the kneading unit 14 per unit time and the total amount of the positive electrode slurry discharged by the kneading unit 14 per unit time are equal. Therefore, the plurality of materials supplied to the kneading section 14 can be continuously transferred to the coater 19 without staying in the pipes 21 to 23 or the kneading section 14.

Further, in the kneading method for producing a battery electrode slurry in the present embodiment, each of the binder supply unit 11, the positive electrode material supply unit 12, and the conductive auxiliary agent supply unit 13 is the initial end, and the coater 19 is the end, and these are communicated with each other. The space formed by the above is sealed. Therefore, between the time when each material is charged into the binder supply unit 11, the positive electrode material supply unit 12, and the conductive auxiliary agent supply unit 13 until the positive electrode slurry is applied to the current collector by the coater 19, these materials are used. And the positive electrode slurry can be suppressed from being exposed to the atmosphere.

Further, in the kneading method for producing a battery electrode slurry in the present embodiment, the space control unit 31 communicates with the above-mentioned closed space. Therefore, this space can be decompressed or filled with an inert gas. Therefore, it is possible to prevent the material and the positive electrode slurry from being exposed to the atmosphere inside this space. Therefore, the quality of the positive electrode slurry can be further stabilized.

<Second Embodiment>
FIG. 2 is a configuration diagram showing an outline of a battery electrode slurry manufacturing kneading device 1A capable of realizing the battery electrode slurry manufacturing kneading method according to the second embodiment of the present invention. The battery electrode slurry producing kneading device 1A is different from the battery electrode slurry producing kneading device 1 according to the first embodiment of the present invention shown in FIG. 1 in that it includes a tank 41, a pipe 28, and a mono pump 58. In the battery electrode slurry manufacturing kneading device 1A, the same components as those of the battery electrode slurry manufacturing kneading device 1 are designated by the same reference numerals, and the description thereof will be omitted.

The tank 41 communicates with the pipe 24 that communicates with the kneading portion 14. The tank 41 stores the positive electrode slurry continuously supplied from the kneading portion 14 via the pipe 24.

A pipe 28 communicates with the tank 41, and the tank 41 continuously supplies the stored positive electrode slurry to the pipe 28. A coater 19 communicates with the pipe 28, and a mono pump 58 and a filter 18 are provided. The tank 41 continuously supplies the stored positive electrode slurry to the pipe 28, and the mono pump 58 urges the positive electrode supplied to the pipe 28 toward the coater 19. An example of the configuration of the tank 41 will be described below with reference to FIG.

FIG. 3 is a cross-sectional view showing an outline of the tank 41. The tank 41 includes a motor 411, a stirring unit 412, and a case 413. The stirring unit 412 is a so-called anchor type stirring blade, and includes a rotating shaft 4121 and a stirring blade 4122. The rotating shaft 4121 is rotationally driven by the motor 411 with the center line in the longitudinal direction of the rotating shaft 4121 as the rotating shaft, and when the rotating shaft 4121 rotates, the stirring blade 4122 also rotates. The tank 41 stirs the stored positive electrode slurry by driving the motor 411 to rotate the stirring blade 4122. The positive electrode slurry enters the tank 41 from a carry-in port (not shown) provided on the side surface of the tank 41 through the inner wall of the tank 41. This is to avoid the inclusion of air bubbles in the positive electrode slurry by entering from above the tank 41. Further, the positive electrode slurry stored in the tank 41 is discharged from a discharge port (not shown) provided on the bottom surface of the tank 41.

According to the kneading method for producing a battery electrode slurry in the present embodiment, the following effects can be obtained in addition to the above-mentioned effects that can be achieved by the kneading method for producing a battery electrode slurry in the first embodiment.

The binder, the positive electrode active material, and the conductive auxiliary agent are supplied to the kneading unit 14 from each of the binder supply unit 11, the positive electrode material supply unit 12, and the conductive auxiliary agent supply unit 13 in a predetermined compounding ratio. .. However, due to the timing of the feeder, the measurement error, the influence based on the transfer (transfer speed, transfer timing, transfer amount, etc.), the quality of the positive electrode slurry that is kneaded in the kneading section 14 and continuously discharged is improved. Variations may occur. However, the kneading device 1A for producing the battery electrode slurry includes a tank 41 between the kneading portion 14 and the coater 19. Therefore, the positive electrode slurry that is kneaded in the kneading section 14 and continuously discharged is stored in the tank 41 and then supplied to the coater 19. Therefore, since the positive electrode slurry kneaded in the kneading section 14 is mixed while being stored in the tank 41, the variation in the quality of the positive electrode slurry at the time of being supplied to the coater 19 is discharged from the kneading section 14. It is smaller than the variation in the quality of the positive electrode slurry at the time. Therefore, the quality of the positive electrode slurry can be stabilized.

Further, in the kneading method for producing a battery electrode slurry in the present embodiment, the tank 41 is provided with a stirring unit 412 for stirring the stored positive electrode slurry. Therefore, the positive electrode slurry kneaded in the kneading section 14 is further mixed while being stored in the tank 41, so that the materials constituting the positive electrode slurry dispersed by kneading do not separate, and the positive electrode slurry is not separated. Can be maintained in a state in which a plurality of materials are kneaded, and the quality of the positive electrode slurry can be further made uniform.

Further, in the kneading method for producing the battery electrode slurry in the present embodiment, since the tank 41 is provided between the kneading portion 14 and the coater 19, the processing amount of the kneading portion 14 and the processing amount of the coater 19 are different. Even if they are different, the tank 41 can be used as a so-called buffer, and a positive electrode slurry in an amount equal to the processing amount of the coater 19 can be supplied to the coater 19. Specifically, when the processing amount of the kneading portion 14 is smaller than the processing amount of the coater 19, the difference is supplemented with the positive electrode slurry stored in the tank 41, and the positive electrode slurry in an amount equal to the processing amount of the coater 19. Can be supplied to the coater 19. Further, when the processing amount of the kneading portion 14 is larger than the processing amount of the coater 19, the difference can be stored in the tank 41 and the positive electrode slurry in an amount equal to the processing amount of the coater 19 can be supplied to the coater 19. .. Therefore, while continuously supplying the positive electrode slurry kneaded by the kneading section 14 to the coater 19, the kneading section 14 and the coater 19 are appropriately used according to the target amount of the positive electrode slurry to be produced, the maintenance situation such as cleaning, and the like. Can be driven independently.

The temperature control unit 71 sets the temperature of the positive electrode slurry stored in the tank 41 lower than the curing temperature of the binder and the viscosity of the positive electrode slurry according to the temperature of the positive electrode slurry measured by the temperature sensor 61. The temperature may be controlled to be higher than the temperature exceeding a predetermined allowable value. In this case, for example, a cooling jacket or a heating jacket may be attached to the tank 41.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within a range that does not deviate from the gist of the present invention.

For example, in each of the above-described embodiments, the case where one kneading portion of the kneading portion 14 is provided has been described. However, two or more kneading portions may be connected in series.

Further, in each of the above-described embodiments, the positive electrode slurry has been described as an example, but the present invention is not limited to this, and can be applied to, for example, the negative electrode slurry.

Further, in the above-described first embodiment, the temperature of the positive electrode slurry discharged from the kneading portion 14 is measured by the temperature sensor 61. However, the present invention is not limited to this, and as shown in FIG. 4, the temperature of the material kneaded in the kneading section 14 may be measured.
FIG. 4 is a configuration diagram showing an outline of a kneading device 1B for producing a battery electrode slurry in which the temperature sensor 61 is provided in the kneading portion 14A. In the kneading device 1B for producing a battery electrode slurry, the temperature sensor 61 measures the temperature of the material kneaded in the kneading unit 14, and the temperature control unit 71 measures the temperature of the material measured by the temperature sensor 61. The temperature of the material kneaded in the kneading unit 14 is controlled to be lower than the curing temperature of the binder and higher than the temperature at which the viscosity of the positive electrode slurry exceeds a predetermined allowable value.
The above-mentioned kneading method for producing a battery electrode slurry by the kneading device 1B for producing a battery electrode slurry is the same as the kneading method for producing a battery electrode slurry in the first embodiment and the kneading method for producing a battery electrode slurry in the second embodiment. It can be effective.

Further, in the above-described first embodiment, the temperature control unit 71 lowers the temperature of the material kneaded in the kneading unit 14 to a temperature lower than the curing temperature of the binder and the viscosity of the positive electrode slurry exceeds a predetermined allowable value. It was decided to control to a higher temperature. However, the temperature is not limited to this, and for example, the temperature of the binder housed in the binder supply unit 11, the temperature of the binder circulating inside the pipe 21, and the temperature of the positive slurry flowing inside the pipe 24 are set as described above. It may be controlled.

Further, in the above-described first embodiment, the binder is supplied from the binder supply unit 11 to the kneading unit 14 by the mono pump 51. However, the present invention is not limited to this, and for example, a diaphragm pump, a piston pump, a plunger pump, a delasco pump, a gear pump, a vane pump and the like can also be used. Further, the binder supply unit 11 is provided at a position higher than the kneading unit 14, and the binder is supplied from the binder supply unit 11 to the kneading unit 14 by urging the binder with pressure by using gravity. Good. Even when gravity is used, it is preferable to provide the mono pump 51 in the pipe 21 in order to control the supply amount of the material to be supplied.

Further, in the above-described first embodiment, one kneading portion 14 is provided, but the present invention is not limited to this, and for example, as shown in FIG. 5, a plurality of kneading portions 14 (two in FIG. 5) are provided in parallel. It may be a thing. In this case, as shown in FIG. 5, only one set of temperature sensors 61 is provided in the subsequent stage of the plurality of kneading portions 14, and the temperature of the positive electrode slurry discharged from each kneading portion 14 and combined is measured by the temperature sensor. The temperature of the positive electrode slurry in each kneading unit 14 is adjusted by the temperature control unit 71 which measures the measurement in 61 and transmits the measurement result. According to this, each of the plurality of kneading portions 14 can be independently driven according to the target amount of the positive electrode slurry to be produced and the maintenance situation such as cleaning. Further, since the discharges from the plurality of kneading units 14 are collectively controlled, the temperature control of the discharges can be realized at a low cost.

Further, in the above-described first embodiment, the binder, the positive electrode active material, and the conductive auxiliary agent are separated from each of the binder supply unit 11, the positive electrode material supply unit 12, and the conductive auxiliary agent supply unit 13, that is, from different configurations. It was supposed to be supplied. However, the present invention is not limited to this, and the binder, the positive electrode active material, and the conductive auxiliary agent may be supplied from the same composition.

Further, in the above-described first embodiment, the mono pump 51 is provided in the pipe 21. However, the present invention is not limited to this, and it may be provided in the pipe 24, or may be provided in a plurality of the pipes 21 and 24. When the pipe 24 is provided, it is preferable to provide a structure for urging the slurry by sucking the slurry by pressure or the like as an urging means. Further, when provided in the pipe 24, the binder is urged by the mono pump 51 provided in the pipe 21 until the first positive electrode slurry is discharged from the kneading portion 14, or the kneading portion 14 has a certain degree of urging force. It is preferable to provide a structure to urge the material. By urging in this way, the material and the slurry can be transferred more smoothly in the kneading device 1 for producing the battery electrode slurry.

Further, instead of using the temperature control jacket, a space in which the cooling water or the hot water can be circulated may be formed inside the kneading portion 14, and the cooling water or the hot water may flow in this space.

Further, the rotation speed of the rotor that kneads the material in the kneading unit 14 is changed by controlling the temperature control unit 71 without using the temperature control jacket (the rotation speed is slowed down at high temperature to suppress heat generation, and the rotation speed at low temperature). To promote heat generation), the temperature of the positive electrode slurry may be adjusted to a desired temperature. It should be noted that the temperature control unit 71 attaches the material group to be kneaded by the mono pump as the rotation speed of the rotor is changed so that the time required for the kneading process does not vary by making the rotation speed of the rotor variable. You may try to adjust the power. If the moving speed of the material varies due to the variable urging force of the MONO pump, a storage means such as a tank 41 is provided on the discharge side of the kneading section 14 to store the positive electrode slurry discharged from the kneading section 14, which is desired. The stored positive electrode slurry may be discharged by a mono pump that gives an urging force.

Further, in each of the above-described embodiments, cooling water or hot water is allowed to flow through the temperature control jacket, but the present invention is not limited to this, and for example, cooling air or hot air may be passed.

Further, in each of the above-described embodiments, three types of materials are supplied to the kneading portion 14, but the present invention is not limited to this, and for example, two types of materials and four types of materials are supplied. May be good.

1, 1A, 1B; Kneading device for producing battery electrode slurry 11; Binder supply section 12; Positive electrode material supply section 13; Conductive aid supply section 14; Kneading section 18; Filter 19; Coaters 21 to 24; Piping 31; Spatial control Unit 32; Control unit 41; Tanks 51, 58; Monopump 61; Temperature sensor 71; Temperature control unit

Claims (6)

A kneading method for producing a battery electrode slurry, which produces a battery electrode slurry by urging, transporting, and kneading a material for producing a battery electrode slurry containing a binder.
A first step in which a plurality of materials for producing the battery electrode slurry are supplied, and the supplied plurality of materials are kneaded and continuously discharged.
The second step of transporting the material discharged in the first step and
In the third step of measuring the temperature of the material being transported in the second step,
Based on the measurement results in the third step, the fourth step of controlling the temperature of the material kneaded in the first step so as to be lower than the curing temperature of the binder,
A kneading method for producing a battery electrode slurry, which comprises. In the fourth step, among the material supplied for kneading in the first step and the material kneaded in the first step based on the measurement result in the third step. The battery electrode according to claim 1, wherein at least one of the temperatures is controlled to be lower than the curing temperature of the binder and higher than the temperature at which the viscosity of the material exceeds a predetermined allowable value. Kneading method for preparing a slurry. A kneading method for producing a battery electrode slurry, which produces a battery electrode slurry by urging, transporting, and kneading a material for producing a battery electrode slurry containing a binder.
A first step in which a plurality of materials for producing the battery electrode slurry are supplied, and the supplied plurality of materials are kneaded and continuously discharged.
The second step of transporting the material discharged in the first step and
In the third step, the material transported in the second step is stored and the stored material is continuously discharged.
In the fourth step of measuring the temperature of the material being transported in the second step,
Based on the measurement results in the fourth step, the fifth step of controlling the temperature of the material kneaded in the first step so as to be lower than the curing temperature of the binder,
A kneading method for producing a battery electrode slurry, which comprises. In the fifth step, based on the measurement result in the fourth step, the material supplied for kneading in the first step, the material kneaded in the first step, and the first step. The temperature of at least one of the materials transported in the second step is controlled to be lower than the curing temperature of the binder and higher than the temperature at which the viscosity of the material exceeds a predetermined allowable value. The kneading method for producing a battery electrode slurry according to claim 3, wherein the method is characterized by the above. The space in which the first step is performed and the space in which the second step is performed communicate with each other to form a closed space.
The kneading method for producing a battery electrode slurry according to claim 1 or 2, further comprising a fifth step of depressurizing the space or filling the space with an inert gas. The space in which the first step is performed, the space in which the second step is performed, and the space in which the third step is performed communicate with each other to form a closed space.
The kneading method for producing a battery electrode slurry according to claim 3 or 4, further comprising a sixth step of depressurizing the space or filling the space with an inert gas.

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