JP2012196595A - Apparatus for kneading paste and method of producing battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for kneading paste, capable of preventing foreign matters generated by abrasion from mixing with paste.SOLUTION: The apparatus 100 for kneading paste includes a container 110 for paste 170 to be stored having been kneaded and stirred. The container 110 includes an inflow port 111c disposed above the liquid surface LF of the paste 170 stored therein to allow the paste 170 to flow thereinto. A feeding means 150 of feeding the paste 170 to the inflow port 111c is disposed outside the container 110. A thin-film forming means 160 is disposed inside the container 110 to form a thin film 171 alongside the inner wall face 111b of the container 110, from the paste 170 fed thereinto via the inflow port 111c. The thin-film forming means 160 includes a scraper 161 that thinly spreads the paste 170 fed thereinto via the inflow port 111c and a spacer 162 that contacts the inner wall face 111b and determines a gap T1 between the scraper 161 and the inner wall face 111b.

Description

  The present invention relates to a paste kneading apparatus and a battery manufacturing method, and more particularly to a paste kneading apparatus for defoaming a kneaded and stirred paste and a battery manufacturing method.

  Batteries are used in various fields such as electronic devices such as mobile phones and personal computers, and vehicles such as hybrid cars and electric cars. Such a battery includes a positive electrode plate, a negative electrode plate, and an electrolyte. When a liquid electrolyte is used, a separator is generally provided between the positive electrode plate and the negative electrode plate.

  Generally, a battery is manufactured through various manufacturing processes. For example, some lithium ion secondary battery manufacturing processes include a paste kneading process, an electrode plate creating process, an electrode body creating process, and a battery assembling process. The paste kneading step is a step of kneading a paste that becomes an electrode mixture layer (a positive electrode mixture layer and a negative electrode mixture layer) that causes an electrode reaction. The electrode plate creation step is a step of creating electrode plates (positive electrode plate and negative electrode plate) by applying paste to the electrode core material (positive electrode core material and negative electrode core material). The electrode body creation step is a step in which a separator is interposed between the positive electrode plate and the negative electrode plate and stacked or wound to form an electrode body. The battery assembly process is a process of assembling a battery by inserting an electrode body into the battery container and injecting an electrolyte.

  Here, in the paste kneading step, for example, a positive electrode active material, a conductive material, a binder, a thickener, and a solvent are mixed in the container and mixed and stirred by a kneading blade and a stirring blade. Thereby, a positive electrode paste is created. Further, the negative electrode paste is similarly prepared. In the paste kneading step described above, the kneading and stirring proceed due to the shearing force acting on the paste, but bubbles are generated as a by-product. The bubbles are generated by nitrogen or oxygen contained in the solution, gas components adsorbed on the surface of the powder, or air taken into the paste during stirring.

  Thus, when kneading / stirring is advanced by shearing force, bubbles are always generated in the paste. For this reason, when the paste is applied to the electrode core material with a lot of bubbles, pinholes and cracks are generated in the active material layer of the electrode plate, and the performance of the electrode is impaired. Moreover, if there are many bubbles contained in the paste, it causes a measurement error in the coarse particle inspection by the paste particle gauge.

  Then, the paste kneading apparatus which reduces the foam contained in a paste is described in the following patent document 1, for example. As shown in FIG. 22, this paste kneading apparatus 800 includes a container 810 for storing the kneaded and stirred paste 870, a main shaft 831 rotated by a motor 880, and a scraper 861 assembled to the main shaft 831. And a screen 862 assembled to the container 810. Accordingly, as shown in FIG. 23, the scraper 861 scrapes the paste 870 containing the foam AW while pressing it against the screen 862. Then, the paste 870 is pushed out from the pores 862 a formed in the screen 862. Thus, the large bubbles AW among the bubbles contained in the paste 870 are crushed and defoamed. The paste 870 pushed out from the pores 862a of the screen 862 is continuously discharged from the container 810 through the discharge pipe 851.

JP 2004-33924 A

  However, in the paste kneading apparatus 800 described above, since the paste 870 passes through the pores 862a of the screen 862, the bubbles AW contained in the paste 870 are crushed. The force with which the scraper 861 presses the paste 870 against the screen 862 needs to be increased. Therefore, depending on the composition (material, solid content concentration, etc.) of the paste 870, the wear of the screen 862 may increase, and foreign matter (such as iron that is the material of the screen 862) due to wear may be mixed in the paste 870.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a paste kneading apparatus and a battery manufacturing method that can prevent foreign matter due to wear from being mixed into the paste.

In order to achieve the above-described problems, the paste kneading apparatus of the present invention has the following configuration.
(1) In a paste kneading apparatus including a container for storing a kneaded and stirred paste, the container is provided with an inlet through which the paste flows in above the liquid level of the stored paste, Outside the container, there is provided a delivery means for sending the paste to the inlet, and in the container, a thin film is formed to form a thin film along the inner wall surface of the container with respect to the paste sent from the inlet Means are provided.
(2) In the paste kneading apparatus described in (1), the container is provided with a discharge port for discharging the paste, and the feeding means removes the paste stored in the container from the discharge port. It is a circulation device that feeds into the inflow port.
(3) In the paste kneading apparatus described in (2), the container is a kneading container in which paste is kneaded and stirred, and is a thin film forming container in which the thin film is formed.
(4) In the paste kneading apparatus described in any one of (1) to (3), a rotating main shaft and a stirring blade that is assembled to the main shaft and stirs the paste are provided in the container. The thin film forming means includes a scraper that is assembled to the main shaft or the stirring blade and thinly extends the paste fed from the inlet.
(5) In the paste kneading apparatus described in (4), the thin film forming means is assembled to the scraper and is in contact with the inner wall surface of the container so that it is between the scraper and the inner wall surface of the container. It has the spacer which prescribes | regulates a clearance gap, It is characterized by the above-mentioned.
(6) In the paste kneading apparatus described in any one of (1) to (3), a rotating main shaft is provided in the container, and the thin film forming means rotates with respect to the inner wall surface of the container. A rotatable roller that comes into contact, a first arm member that is assembled to the main shaft and extends in a radial direction with respect to the axial center of the main shaft, and a radially outer end that extends in a radial direction with respect to the axial center of the main shaft A second arm member that rotatably supports the rotating roller at a portion and is tiltably assembled to the first arm member at a radially inner end, and is assembled to the second arm member. And a scraper for thinly extending the paste fed from the inflow port.
(7) In the paste kneading apparatus described in any one of (1) to (3), the thin film forming unit holds the paste fed from the inlet and has a gap between the inner wall surface of the container and the container. And a holding member that drops the held paste from the gap.
(8) In the paste kneading apparatus described in (7), the holding member has an extending part extending in a vertical direction, and the second paste is dropped by dropping the held paste along the extending part. A thin film is formed.
(9) In the paste kneading apparatus described in (1) or (2), the container is different from a kneading container in which paste is kneaded and stirred, and all of the kneaded and stirred from the kneading container The paste is fed into the inlet by the delivery means.
(10) In the paste kneading apparatus described in any one of (1) to (9), a decompression device that reduces the pressure in the container is provided outside the container.

In order to achieve the above-described problems, the battery manufacturing method of the present invention has the following configuration.
(11) A paste kneading step for preparing a kneaded and stirred paste from a paste material using the paste kneading apparatus described in any one of (1) to (10), and applying the paste to an electrode core material The electrode layer is made by forming a paste layer and drying the paste layer to form a positive electrode plate or a negative electrode plate, and the positive electrode plate and the negative electrode plate are laminated or wound with a separator interposed therebetween to form an electrode. And a battery assembly step of placing the electrode body inside the battery container and injecting an electrolyte into the battery container to seal the body.

The operation and effect of the paste kneader described above will be described.
(1) The sending means feeds the kneaded and stirred paste to the inlet of the container. Thereby, a paste flows in from an inflow port above the liquid level of the paste to be stored. And a thin film formation means forms a thin film along the inner wall face of a container with respect to the paste sent from the inflow port. Thereby, bubbles contained in the paste come to actively float on the interface of the thin film, and the defoaming of the paste can be effectively promoted. In this way, defoaming is achieved by forming a thin film on the inner wall surface of the container positioned above the liquid level of the paste, so that foreign matter due to wear can be hardly mixed into the paste.
(2) In this case, since the sending means which is a circulation device repeatedly sends the paste stored in the container from the discharge port to the inlet, a thin film can be repeatedly formed on the inner wall surface of the container, and the paste can be formed by one container. Defoaming can be effectively promoted.
(3) In this case, the paste is kneaded and stirred in one container, and the foam is defoamed by forming a thin film. For this reason, by adding a defoaming function to a kneading container in which paste is kneaded and stirred, paste kneading and stirring and paste defoaming can be performed inexpensively and efficiently.
(4) In this case, when the scraper stretches the paste thinly, a large shearing force acts on the paste, and the viscosity of the paste is lowered, so that the defoaming effect is high. Furthermore, even immediately after the scraper extends the paste thinly, the viscosity of the paste is relatively low, so the defoaming effect is relatively high. And by increasing the rotation speed of the scraper, the paste becomes difficult to return to a state where the viscosity is high, that is, the state where the viscosity is low can be maintained, and defoaming can be performed more effectively.
(5) In this case, the contact area with which the inner wall surface of the container contacts can be reduced by the spacer, and the wear of the inner wall surface can be reduced. As a result, foreign matter due to wear can be made extremely difficult to be mixed into the paste.
(6) In this case, as the main shaft rotates, the scraper stretches the paste thinly to form a thin film along the inner wall surface. At this time, since the rotating roller is in contact with the inner wall surface in a rotatable manner, the position of the scraper is a position relative to the inner wall surface, and the gap between the scraper and the inner wall surface is always kept constant. be able to. That is, even if torque is applied from the inner wall surface to the rotating roller due to the rotation of the main shaft due to the manufacturing error of the container, the radially inner end of the second arm member swings the head with respect to the first arm member (tilt). By doing so, the above-described torque can be absorbed, and the gap between the scraper and the inner wall surface can always be kept constant.
(7) In this case, the paste falls from the gap between the holding member and the inner wall surface of the container, and a thin film is formed along the inner wall surface of the container. In this way, since the thin film is formed in a static situation where the shear force does not act, foreign matter due to wear on the inner wall surface is pasted compared to the case where the thin film is formed in a dynamic situation where the shear force acts. It can be made very difficult to mix. For this reason, it is suitable when creating a paste with high hardness according to the composition (material, solid content concentration) of the paste.
(8) In this case, the paste held by the holding member falls along the extending portion to form the second thin film. As a result, the amount of paste thin film can be increased, and the defoaming effect can be increased (defoaming time is reduced).
(9) In this case, all pastes kneaded and stirred in the kneading container are fed into a container different from the kneading container, and a thin film is formed along the inner wall surface of the container. For this reason, even if foam remains in a specific portion in the kneading container, all the paste can be defoamed in a container different from the kneading container, and thus the defoaming effect can be prevented from being lowered.
(10) In this case, since the decompression device lowers the pressure in the container, the bubbles contained in the paste are likely to float on the interface that is the boundary between the liquid layer and the gas layer (the probability of floating increases). ) And bubbles that float to the interface are easily repelled. As a result, the defoaming of the paste can be promoted.

The operation and effect of the battery manufacturing method described above will be described.
(11) In the paste kneading step, the paste kneading device forms a paste thin film kneaded and stirred along the inner wall surface of the container, and the defoamed paste is effectively defoamed with little contamination due to wear. create. Thereby, in an electrode plate preparation process, it can prevent that the performance of an electrode will be impaired because a pinhole and a crack generate | occur | produce in the active material layer of an electrode plate. As a result, a battery having excellent quality can be manufactured.

It is a schematic sectional drawing of a battery. It is a perspective view of the wound electrode body shown in FIG. FIG. 3 is a development view showing a wound structure of the wound electrode body shown in FIG. 2. It is a perspective sectional view of a positive electrode plate or a negative electrode plate. 1 is a schematic cross-sectional view showing a paste kneading apparatus according to a first embodiment. FIG. 6 is an enlarged perspective view of a portion X shown in FIG. 5. It is the figure which compared the defoaming effect at the time of defoaming by a different method. It is the figure which showed the relationship between the viscosity of a paste, and time when changing the shear rate which acts on a paste. 1 is a schematic cross-sectional view showing a paste kneading apparatus according to a first modified embodiment of the first embodiment. It is the rough sectional view showing the paste kneading device concerning the 2nd modification of a 1st embodiment. It is the perspective view which expanded and showed the thin film formation means of the paste kneading apparatus shown in FIG. It is the rough sectional view showing the paste kneading device concerning a 2nd embodiment. It is sectional drawing seen from the direction of 13-13 shown in FIG. FIG. 13 is an enlarged view of a Y portion shown in FIG. 12. It is the figure which compared the amount of Fe increase of a paste when defoaming by a different method. It is the schematic sectional drawing which showed the paste kneading apparatus which concerns on deformation | transformation embodiment of 2nd Embodiment. It is sectional drawing seen from the 17-17 direction shown in FIG. It is an enlarged view of Z part shown in FIG. It is the schematic sectional drawing which showed the paste kneading apparatus which concerns on 3rd Embodiment. It is the figure which compared the defoaming effect at the time of using the paste kneading apparatus which concerns on 1st Embodiment, and the paste kneading apparatus which concerns on 3rd Embodiment. It is the schematic sectional drawing which showed the paste kneading apparatus which concerns on deformation | transformation embodiment of 3rd Embodiment. It is the schematic block diagram which showed the conventional paste kneading apparatus. It is sectional drawing which showed the relationship between the scraper shown in FIG. 22, and a screen.

1. Battery A battery according to this embodiment will be described. FIG. 1 is a schematic cross-sectional view of the battery 1. The battery 1 is a cylindrical lithium ion secondary battery. The battery 1 is a battery cell sealed with a battery container including a battery container 2 and a lid 3 as shown in FIG. The battery 1 includes a wound electrode body 10, a positive electrode current collector plate 20, and a negative electrode current collector plate 30. In addition, an electrolytic solution is injected into the battery container 2.

The electrolytic solution injected into the battery container 2 is obtained by dissolving an electrolyte in an organic solvent. Examples of organic solvents include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC), and ester solvents such as γ-butylactone (γ-BL), di- An organic solvent containing an ether solvent such as ethoxyethane (DEE) can be used. In addition, as a salt that is an electrolyte, lithium salts such as lithium perchlorate (LiClO ₄ ), lithium borofluoride (LiBF ₄ ), and lithium hexafluorophosphate (LiPF ₆ ) can be used.

  The wound electrode body 10 repeatedly charges and discharges in the electrolytic solution and directly contributes to power generation. The positive electrode current collector plate 20 is a positive electrode current collector connected to the positive electrode core material of the wound electrode body 10. The material is aluminum. The negative electrode current collector plate 30 is a negative electrode current collector connected to the negative electrode core material of the wound electrode body 10. The material is copper. Here, FIG. 2 is a perspective view of the wound electrode body 10 shown in FIG.

  As shown in FIG. 2, the wound electrode body 10 is an electrode body in which a positive electrode plate and a negative electrode plate are wound around an axis 11 and separators S and T are interposed therebetween. The shaft core 11 is a member that becomes the center when the wound electrode body 10 is wound. Its shape is cylindrical. The diameter of the shaft core 11 is about 3 to 20 mm. Examples of the material of the shaft core 11 include polyphenylene sulfide (PPS). In FIG. 2, a positive electrode non-coated portion P2 and a negative electrode non-coated portion N2 described later appear.

  The separators S and T are porous films such as polyethylene and polypropylene. The thickness of the separators S and T is about 10 to 50 μm. Here, the separator S and the separator T are made of the same material. For the understanding of the above winding order, only the codes are distinguished as S and T. Here, FIG. 3 is a development view showing a wound structure of the wound electrode body 10 shown in FIG.

  As shown in FIG. 3, the wound electrode body 10 is wound in a state where the positive electrode plate P, the separator S, the negative electrode plate N, and the separator T are stacked in this order from the inside. The positive electrode plate P has a positive electrode coating part P1 and a positive electrode non-coating part P2. The positive electrode coating part P1 is a part where a positive electrode mixture layer containing a positive electrode active material or the like is formed on a positive electrode core material. The positive electrode non-coating portion P2 is a portion where the positive electrode mixture layer is not formed on the positive electrode core material. The negative electrode plate N has a negative electrode coating part N1 and a negative electrode non-coating part N2. The negative electrode coating part N1 is a part where a negative electrode mixture layer containing a negative electrode active material or the like is formed on a negative electrode core material. The negative electrode non-coated portion N2 is a portion where the negative electrode mixture layer is not formed on the negative electrode core material. An arrow A in FIG. 3 indicates the width direction (vertical direction in FIG. 2) of the positive electrode plate P, the negative electrode plate N, and the separators S and T. 3 indicates the longitudinal direction of the positive electrode plate P, the negative electrode plate N, and the separators S and T (the circumferential direction of the wound electrode body 10 in FIG. 2).

  Here, FIG. 4 is a perspective sectional view of the positive electrode plate P (negative electrode plate N). Each reference numeral outside the parentheses in FIG. 4 indicates each part in the case of the positive electrode. Moreover, each code | symbol in the parenthesis of FIG. 4 has shown each part in the case of a negative electrode. The direction indicated by arrow A in FIG. 4 is the same as the direction indicated by arrow A in FIG. That is, it is the width direction of the positive electrode plate P. The direction indicated by arrow B in FIG. 4 is the same as the direction indicated by arrow B in FIG. That is, it is the longitudinal direction of the positive electrode plate P.

  As shown in FIG. 4, the positive electrode plate P is obtained by forming a positive electrode mixture layer PA on a part of both surfaces of a belt-like positive electrode core material PB. On the left side of FIG. 4, a positive electrode non-coated portion P2 of the positive electrode plate P protrudes in the width direction. The positive electrode non-coated portion P2 is formed in a strip shape. The positive electrode uncoated portion P2 is a region where the positive electrode active material is not applied to both surfaces of the positive electrode core material PB. Therefore, in the positive electrode non-coating portion P2, the positive electrode core material PB is still exposed. On the other hand, on the right side of FIG. 4, there is no protrusion corresponding to the positive electrode non-coated portion P2. In the positive electrode coating portion P1, the positive electrode mixture layer PA is formed with a uniform thickness on both surfaces of the positive electrode core material PB.

The positive electrode mixture layer PA is a layer obtained by applying a positive electrode paste containing a positive electrode active material, a conductive material, a binder, a thickener, and a solvent to an aluminum foil that is the positive electrode core material PB and then drying it. The positive electrode active material is a material that can occlude and release lithium ions. As the positive electrode active material, lithium composite oxides such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), and lithium cobaltate (LiCoO ₂ ) are used.

  Carbon materials such as carbon powder and carbon fiber can be used as the conductive material for the positive electrode. For example, carbon powder such as acetylene black, furnace black, ketjen black, etc., and carbon powder such as graphite powder.

  The binder for the positive electrode is preferably a polymer that is insoluble (or hardly soluble) in the electrolytic solution and is dispersed in the solvent used for the positive electrode paste. For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoro Fluorine resin such as ethylene copolymer (ETFE), vinyl acetate copolymer, styrene butadiene rubber (SBR), acrylic acid-modified SBR resin (SBR latex), rubber such as gum arabic can be used. Alternatively, a combination of these may be used. The binder is not necessarily limited to the above polymer.

  As the thickener for the positive electrode, cellulose such as carboxymethylcellulose (CMC), methylcellulose (MC), cellulose acetate phthalate (CAP), hydroxypropylmethylcellulose (HPMC), and hydroxypropylmethylcellulose phthalate (HPMCP) is used. However, it is not necessarily limited to the cellulose described above, and can be used. Water is mentioned as a solvent for positive electrodes. In addition, N-methyl-2-pyrrolidone (NMP) may be used. Other lower alcohols and lower ketones can also be used.

  The negative electrode plate N is obtained by forming a negative electrode mixture layer NA on a part of both surfaces of a strip-shaped negative electrode core material NB, as indicated by reference numerals in parentheses in FIG. Further, similarly to the positive electrode, there are a negative electrode coating portion N1 and a negative electrode non-coating portion N2. However, as shown in FIG. 3, at the time of winding, the positive electrode non-coated portion P2 and the negative electrode non-coated portion N2 are wound in a state of protruding to the opposite side.

  The negative electrode mixture layer NA is a layer obtained by applying a negative electrode paste containing a negative electrode active material, a binder, a thickener, and a solvent to a copper foil that is the negative electrode core material NB and then drying it. The negative electrode active material is a material that can occlude and release lithium ions. As the negative electrode active material, a carbon-based material containing a graphite structure at least partially is used. For example, amorphous carbon, non-graphitizable carbon (hard carbon), graphitizable carbon (soft carbon), graphite (graphite), or a carbon material having a combination thereof can be used.

  As the binder for the negative electrode, those mentioned for the binder for the positive electrode can be used. As the thickener for the negative electrode, those listed for the thickener for the positive electrode can be used. As the solvent for the negative electrode, those mentioned for the positive electrode solvent can be used.

2. Paste Kneading Device According to First Embodiment FIG. 5 is a schematic sectional view showing a paste kneading device 100 according to the first embodiment. The paste kneading apparatus 100 creates the above-described positive electrode paste or negative electrode paste.

  As shown in FIG. 5, the paste kneading apparatus 100 includes a container 110, a desper blade 120 as a kneading blade, an anchor blade 130 as a stirring blade, and a decompression device 140. In the paste kneading apparatus 100, a positive electrode paste 170 (hereinafter referred to as “paste 170”) is prepared by batch processing.

  The container 110 is a kneading container in which the paste 170 is kneaded and stirred, and stores the kneaded and stirred paste 170. The container 110 includes a cylindrical container body 111 that is open at the top, and a lid member 112 that covers the top of the container body 111. The container 110 is mixed with the above-described positive electrode active material, conductive material, thickener, binder, and solvent (paste material) for creating the paste 170 with the lid member 112 removed. It has become. The container body 111 stores the paste 170 at about half the height. A discharge port 111 a for discharging the paste 170 after being kneaded and stirred is provided at the lower portion of the container body 111. Here, the paste before kneading and stirring is referred to as paste 170A, and the paste after kneading and stirring is referred to as paste 170.

  The desper blade 120 imparts a shearing force to the paste 170A to knead the paste 170A. The desper blade 120 is assembled to a motor (not shown) and is rotatable. The rotational speed of the desper blade 120 is set to about 2000 rpm, for example. The rotation of the desper blade 120 causes a shearing force to act on the paste 170A and the kneading proceeds, but bubbles are generated as a by-product. When the paste 170 contains many bubbles, it causes a measurement error in the coarse particle inspection by the particle gauge of the paste, or causes a pinhole or a crack in the active material layer of the electrode plate. .

  The anchor blade 130 stirs the paste 170A to stir the paste 170A. The anchor blade 130 is assembled to the boss 132 of the main shaft 131 and extends from the boss 132 in a J shape. The main shaft 131 is disposed at the center of the container body 111 and is assembled to a motor (not shown). For this reason, when the main shaft 131 rotates, the anchor blades 130 rotate and the paste 170A is stirred. The rotation speed of the anchor blade 130 is set to about 50 rpm, for example.

  The decompression device 140 is provided outside the container 110 and reduces the pressure in the container 110. The decompression device 140 includes a connection pipe 141 connected to the container 110, a vacuum pump 142 that exhausts air in the container 110, and a valve 143 that controls the discharge of air. The decompression device 140 decompresses the pressure in the container 110 so as to be about 6650 to 13300 Pa. By reducing the pressure in the container 110 in this way, the bubbles contained in the paste 170 are likely to float on the interface that is the boundary between the liquid layer and the gas layer (the probability of rising) increases, and at the interface. Floating bubbles are easy to pop. That is, the decompression device 140 promotes defoaming of the paste 170 by decompressing the inside of the container 110.

  By the way, the paste kneading apparatus 100 uses the inner wall surface 111b of the container body 111 to form a thin film 171 of the paste 170 on the inner wall surface 111b. This is because when the thin film 171 is formed, bubbles are likely to float on the interface of the thin film 171 (the probability of rising) increases, and the defoaming of the paste 170 is effectively promoted. When the defoaming is performed by forming the thin film 171 of the paste 170 on the inner wall surface 111b as described above, the defoaming is performed by the paste 870 passing through the pores 862a of the screen 862 as described in Patent Document 1 described above. Compared to the case (see FIG. 23), foreign matter due to wear (iron or the like) can be made less likely to enter the paste 170. Therefore, a configuration for forming the thin film 171 in the paste kneading apparatus 100 will be described below.

  The paste kneading apparatus 100 includes a sending unit 150 outside the container 110 and a thin film forming unit 160 inside the container 110. The delivery means 150 feeds the paste 170 to the inflow port 111 c provided in the container main body 111. The inflow port 111 c is a hole that is located above the liquid level LF of the paste 170 and is formed in the peripheral wall of the container main body 111. The delivery unit 150 includes a discharge pipe 151, a first delivery pipe 152, a second delivery pipe 153, a discharge pump 154, and a three-way valve 155.

  One end of the discharge pipe 151 is connected to the discharge port 111 a of the container main body 111. On the other hand, the other end of the discharge pipe 151 is connected to the first delivery pipe 152 via the three-way valve 155 and to the second delivery pipe 153. The first delivery pipe 152 is for feeding the paste 170 again into the container body 111. The first delivery pipe 152 is connected to the inlet 111c of the container body 111.

  The second delivery pipe 153 is for sending the defoamed paste 170 into a tank used in a paste coating process (not shown). The discharge pump 154 is for discharging the paste 170 in the container 110 to the discharge pipe 151. The three-way valve 155 switches the flow of the paste 170 from the discharge pipe 151 to the first delivery pipe 152 and the flow of the paste 170 from the discharge pipe 151 to the second delivery pipe 153. Thus, the paste 170 in the container 110 can be circulated through the discharge pipe 151 and the first delivery pipe 152. That is, the delivery unit 150 is a circulation device that sends the paste 170 stored in the container 110 from the discharge port 111a to the inflow port 111c.

  The thin film forming means 160 forms the thin film 171 along the inner wall surface 111b of the container main body 111 with respect to the paste 170 sent from the inflow port 111c. The thin film forming means 160 includes a scraper (brush member) 161 and a spacer 162. Here, FIG. 6 is an enlarged perspective view of a portion X shown in FIG.

  The scraper 161 thinly extends the paste 170 that falls from the inlet 111c along the inner wall surface 111b. As shown in FIG. 6, the scraper 161 is formed in a flat plate shape, and is assembled to the upper portion of the anchor blade 130 using a fixing jig 163 and a bolt 164. The upper portions of the scraper 161 and the anchor blade 130 are exposed upward from the liquid level LF of the paste 170. A gap T1 (see FIG. 5) between the scraper 161 and the inner wall surface 111b of the container body 111 is set to 2 mm, for example, and a thickness T2 of the scraper 161 is set to 3 mm, for example. The scraper 161 is made of, for example, silicon rubber.

  The spacer 162 defines a gap T <b> 1 between the scraper 161 and the inner wall surface 111 b of the container main body 111. The spacers 162 are formed in a rod shape extending in the left-right direction in FIG. 6 (the radial direction from the axial center of the container 110), and three spacers 162 are bonded to the scraper 161. Each spacer 162 is in direct contact with the inner wall surface 111b. The thickness T3 of each spacer 162 is set to 2 mm, for example, and the width T4 of each spacer 162 is set to 2 mm, for example. These spacers 162 are made of, for example, a fluorocarbon resin.

  By the way, if the scraper 161 directly contacts the inner wall surface 111b of the container body 111, the contact area between the scraper 161 and the inner wall surface 111b is large. In this case, the wear of the inner wall surface 111b is large, and the amount of foreign matter (such as iron that is the material of the container 110) mixed into the paste 170 due to wear increases. For this reason, when the spacer 162 is in direct contact, the contact area between the spacer 162 and the inner wall surface 111b can be reduced, and wear of the inner wall surface 111b can be reduced. As a result, foreign matter due to wear is extremely difficult to be mixed into the paste 170. When the spacer 162 is in direct contact with the inner wall surface 111b, the soft scraper 161 made of silicon rubber is deformed so as not to be in direct contact with the inner wall surface 111b as the spacer 162 is deformed. Thus, the gap T1 between the scraper 161 and the inner wall surface 111b of the container main body 111 is maintained at about 2 mm.

Next, the effect of the paste kneading apparatus 100 will be described.
According to the paste kneading apparatus 100 of the first embodiment, first, a positive electrode active material, a conductive material, a thickener, a binder, and a solvent as a positive electrode paste material are mixed in the container 110. Then, the disperse blade 120 and the anchor blade 130 rotate, and the paste 170A is kneaded and stirred. At this time, the generated foam contains a lot of bubbles. The inside of the container 110 is always decompressed by the decompression device 140.

Thus, when the viscosity ν of the paste 170 when the shear rate γ acting on the paste 170 is 10 s ⁻¹ becomes less than 15000 mPa · s, the delivery means 150 removes the paste 170 in the container 110 from the discharge pipe 151 and the first It again feeds into the container 110 through the delivery tube 152. Thereby, the paste 170 flows in from the inlet 111c above the liquid level LF of the paste 170, and falls along the inner wall surface 111b. At this time, since the anchor blade 130 is rotating, the scraper 161 assembled to the anchor blade 130 thinly stretches the paste 170 that falls along the inner wall surface 111b. As a result, the thin film 171 is formed along the inner wall surface 111b. Accordingly, the bubbles positively float on the interface of the thin film 171 and the defoaming of the paste 170 can be effectively promoted. In this way, defoaming is achieved by forming the thin film 171 on the inner wall surface 111b using the inner wall surface 111b positioned above the liquid level LF of the paste 170, so that foreign matter due to wear can be hardly mixed into the paste 170. .

  When the kneading / stirring and defoaming of the paste 170 proceeds and the viscosity ν of the paste 170 becomes smaller than, for example, 1500 mPa · s, the three-way valve 155 causes the paste 170 from the discharge pipe 151 to the second delivery pipe 153. Switch to the flow. Thereby, the paste 170 after defoaming is sent to the tank used in the paste coating process.

  Moreover, according to this paste kneading apparatus 100, the sending means 150 which is a circulation device repeatedly sends the paste 170 into the container 110. For this reason, the thin film 171 can be repeatedly formed on the inner wall surface 111 b of the container 110, and the defoaming of the paste 170 can be effectively promoted by the single container 110.

  Moreover, according to this paste kneading apparatus 100, the container 110 is a kneading container in which the paste 170 is kneaded and stirred, and is a thin film forming container in which the thin film 171 is formed. That is, in one container 110, the paste 170 is kneaded and stirred, and the paste 170 is defoamed by forming the thin film 171. Therefore, by adding a defoaming function to the kneading container in which the paste 170 is kneaded and stirred, the kneading and stirring of the paste 170 and the defoaming of the paste 170 can be performed inexpensively and efficiently. Specifically, when defoaming is performed using a centrifugal vacuum defoaming apparatus, which is a dedicated defoaming apparatus, the cost is increased by about 10 million yen. According to this paste kneading apparatus 100, the conventional paste kneading is performed. It is only necessary to add the sending means 150 and the thin film forming means 160 to the apparatus, and the cost can be increased by about 500,000 yen.

  Here, FIG. 7 is a diagram comparing the defoaming effect. FIG. 7 shows the grain gauge reading Q (measured value of grain size) of the paste when the same paste is defoamed by different methods. It means that the smaller the grain gauge reading Q, the smaller the amount of foam contained in the paste and the higher the defoaming effect.

  In FIG. 7, at S1, the particle gauge reading Q of the paste immediately after kneading and stirring using a conventional paste kneading apparatus (an apparatus in which the sending means 150 and the thin film forming means 160 are not provided in the paste kneading apparatus 100) is It is shown. The grain gauge reading Q in this case is about 80 μm and the paste is not defoamed. In S2, the grain gauge reading Q of the paste that has been defoamed by stirring for about 10 minutes after kneading and stirring using a conventional paste kneading apparatus is shown. In this case, the grain gauge reading Q is about 75 μm, and the defoaming effect is low.

  In S3, the particle gauge reading Q of the paste that has been defoamed by stirring for about 3 hours after kneading and stirring using a conventional paste kneading apparatus is shown. The grain gauge reading Q in this case is about 55 μm, and the defoaming effect is high, but the defoaming time is long. In S4, the particle gauge reading Q of the paste that has been kneaded and stirred using a conventional paste kneader and then defoamed using a centrifugal vacuum defoamer is shown. In this case, the grain gauge reading Q is about 50 μm, and the defoaming effect is high and the defoaming time is short, but the cost increase is large.

  In S5, the particle gauge reading Q of the paste defoamed by forming the thin film 171 for about 10 minutes after kneading and stirring using the paste kneading apparatus 100 according to the present embodiment is shown. In this case, the grain gauge reading Q is about 50 μm, and the defoaming effect is high and the defoaming time is short. Furthermore, as described above, since the centrifugal vacuum defoaming device is not used, the increase in cost is small.

Next, the effect of the scraper 161 will be described with reference to FIG. FIG. 8 is a diagram showing the relationship between the viscosity ν of the paste and the time t when the shear rate γ acting on the paste is changed. In FIG. 8, the shear rate γ is 2s ⁻¹ when the time t is 0 to 10 seconds, then the shear rate γ is 10 s ⁻¹ when the time t is 10 to 20 seconds, and finally The shear rate γ is 2 s ⁻¹ between the time t and 20-30 seconds. That is, FIG. 8 shows the viscosity ν when a low shear force acts on the paste first, then a high shear force acts on the paste, and finally a low shear force acts on the paste.

  By the way, the paste 170 is a fluid having thixotropy. The thixotropy is a physical property of a fluid in which the viscosity ν is increased at normal times or when a low shear force is applied, and the viscosity ν is decreased when a high shear force is applied. Here, the lower the viscosity ν of the paste 170, the easier it is for bubbles contained in the paste 170 to float on the interface of the paste 170 (the probability of floating) increases. Therefore, in order to increase the defoaming effect, it is preferable to reduce the viscosity ν of the paste 170.

  Therefore, when the time t is from 0 to 10 seconds in FIG. 8, the viscosity ν is about 2200 mPa · s, and the viscosity ν is high. This state can be regarded as the state of the paste 170 before the scraper 161 thinly stretches the paste 170, or the state of the paste 170 when the scraper 161 is not provided. For this reason, in this state, the viscosity ν of the paste 170 is high and the defoaming effect is low. Next, in FIG. 8, when the time t is between 10 and 20 seconds, the viscosity ν is about 900 mPa · s, and the viscosity ν is low. This state can be regarded as the state of the paste 170 when the scraper 161 extends the paste 170 thinly. For this reason, in this state, the viscosity ν of the paste 170 is low and the defoaming effect is high.

  Finally, in FIG. 8, when the time t is between 20 seconds and 30 seconds, the viscosity ν increases from about 1600 mPa · s to about 2200 mPa · s, and returns to a state where the viscosity ν is high (recovered). ). This state can be regarded as a state of the paste 170 after the scraper 161 extends the paste 170 thinly. Here, when the time t is around 22 seconds in FIG. 8, the viscosity ν is about 1600 mPa · s, and the viscosity ν is still relatively low. From this, it can be said that the defoaming effect is relatively high immediately after the scraper 161 extends the paste 170 thinly.

  In short, when the scraper 161 stretches the paste 170 thinly, a large shearing force acts on the paste 170 and the viscosity ν of the paste 170 is lowered, so that the defoaming effect is high. Further, even immediately after the scraper 161 thinly stretches the paste 170, the viscosity ν of the paste 170 is relatively low, so the defoaming effect is relatively high. Then, by increasing the rotational speed of the scraper 161 (main shaft 131), the paste 170 becomes difficult to return to a state where the viscosity ν is high, that is, the state where the viscosity ν is low can be maintained, and defoaming is more effectively performed. can do.

3. Battery Manufacturing Method Next, a battery manufacturing method will be described. The battery manufacturing method according to the present embodiment is characterized in that the paste kneading apparatus 100 is used to create a positive electrode paste for forming the positive electrode mixture layer PA and a negative electrode paste for forming the negative electrode mixture layer NB. .

3-1. Paste kneading step A positive electrode active material, a conductive material, a thickener, a binder, and a solvent as a positive electrode paste material are mixed in the container 110 of the paste kneading apparatus 100. Next, the disperse blade 120 and the anchor blade 130 are rotated to knead and stir the paste 170A. Subsequently, the sending means 150 sends the paste 170 in the container 110 to the inlet 111c. As a result, the scraper 161 assembled to the stirring blade 130 thins the paste 170 falling along the inner wall surface 111b. As a result, the thin film 171 is formed along the inner wall surface 111b, and the bubbles positively float on the interface of the thin film 171. Thus, defoamed paste 170 (positive electrode paste) is created. A negative electrode paste can be similarly prepared.

3-2. Electrode plate production process The positive electrode plate P is produced using an electrode plate production apparatus (not shown). That is, the paste 170 (positive electrode paste) is applied to one end surface and the other end surface of the positive electrode core material PB. Next, the applied paste 170 is dried. Thereby, the positive electrode plate P is created. The negative electrode plate N can be similarly prepared.

3-3. Next, using a winding device (not shown), the positive electrode plate P and the negative electrode plate N are laminated and wound with the separators S and T interposed therebetween. Here, as shown in FIG. 3, the positive electrode plate P, the separator S, the negative electrode plate N, and the separator T are stacked and wound in order from the inside. Thereby, the wound electrode body 10 is created.

3-4. Battery Assembly Process Subsequently, the wound electrode body 10 is disposed in the battery container 2. And electrolyte solution is inject | poured inside the battery container 2, the lid | cover 3 is assembled | attached, and it seals. Thereby, the battery 1 is assembled. Thereafter, processing such as conditioning and aging, and various inspection processes may be performed. The battery 1 of the present embodiment is manufactured through the above steps.

  The effects of the battery manufacturing method described above will be described. In the paste kneading step, the paste kneading apparatus 100 formed the thin film 171 of the paste 170 kneaded and stirred along the inner wall surface 111b of the container 110, and the defoaming was effectively performed with less contamination due to wear. A paste 170 is created. Thereby, in an electrode plate preparation process, it can prevent that the performance of an electrode will be impaired by generating a pinhole and a crack in the active material layer of electrode plates P and N. As a result, the battery 1 with excellent quality can be manufactured.

4). Paste Kneading Device According to First Modified Embodiment of First Embodiment FIG. 9 is a schematic cross-sectional view showing a paste kneading device 100A according to a first modified embodiment of the first embodiment. The thin film forming unit 160A of the paste kneading apparatus 100A includes a scraper 161, a spacer 162, a support plate 165, a connecting rod 166, and a connecting tool 167. The support plate 165 is for supporting the scraper 161 and is assembled to the connector 167 via a connecting rod 166. The connecting rod 166 extends in the radial direction of the main shaft 131. The connector 167 is assembled to the main shaft 131 and can rotate integrally with the main shaft 131. Thus, the scraper 161 is assembled to the main shaft 131 via the support plate 165, the connecting rod 166, and the connecting tool 167. Since the other configuration of the first modified embodiment is the same as that of the first embodiment described above, the same reference numerals are given to the corresponding portions, and the description thereof is omitted. Moreover, since the effect of this 1st modified embodiment is the same as the effect of 1st Embodiment mentioned above, the description is abbreviate | omitted.

5. Paste Kneading Device According to Second Modified Embodiment of First Embodiment FIG. 10 is a schematic cross-sectional view showing a paste kneading device 100B according to a second modified embodiment of the first embodiment. FIG. 11 is an enlarged perspective view showing the thin film forming means 160B of the paste kneading apparatus 100B. As shown in FIGS. 10 and 11, the thin film forming means 160B includes a rotating roller 180, a first arm member 181, a second arm member 182, a support roller 183, a support plate (support member) 184, The above-described scraper 161, fixing jig 163, and bolt 164 are provided.

  The rotation roller 180 is for keeping the distance (gap T1) with respect to the inner wall surface 111b of the scraper 161 constant. As shown in FIG. 11, the rotating roller 180 is in contact with the inner wall surface 111b so as to be rotatable around the axis O2. By this rotating roller 180, the position of the scraper 161 becomes a position with reference to the inner wall surface 111b. Here, as shown in FIG. 10, the position where the rotating roller 180 contacts the inner wall surface 111b is set above the position of the inlet 111c into which the paste 170 is fed. This is to prevent wear that may occur when the rotating roller 180 contacts the inner wall surface 111 b from being mixed into the thin film 171 of the paste 170.

  The first arm member 181 and the second arm member 182 extend in the radial direction with respect to the axial center O1 of the main shaft 131. The radially inner end 181 a of the first arm member 181 is joined to the large diameter portion 133 of the main shaft 131. On the other hand, the radially outer end 181b of the first arm member 181 is assembled to the radially inner end 182a of the second arm member 182 via a support roller 183 so as to be tiltable. That is, the radially outer end 181b of the first arm member 181 and the radially inner end 182a of the second arm member 182 can be swung as shown by the black arrows in FIG. The radially outer end 182b of the second arm member 182 supports the rotating roller 180 in a rotatable manner and supports the support plate 184.

  The support plate 184 is for supporting the scraper 161. The support plate 184 is a flat plate extending in the vertical direction, and is fixed to the radially outer end 182b of the second arm member 182 at the upper end. The scraper 161 is assembled to the support plate 184 using a fixing jig 163 and a bolt 164. A gap T1 between the scraper 161 and the inner wall surface 111b is set to 2 mm, for example. Since the other configuration of the second modified embodiment is the same as the configuration of the first embodiment described above, the same reference numerals are given to the corresponding portions, and the description thereof is omitted.

  The effects according to the second modified embodiment of the first embodiment will be described. According to the thin film forming unit 160B of the paste kneading apparatus 100B, as the main shaft 131 rotates about the axis O1, the scraper 161 extends the paste 170 thinly and forms the thin film 171 along the inner wall surface 111b. At this time, since the rotation roller 180 is rotatably contacted with the inner wall surface 111b, the scraper 161 is positioned with respect to the inner wall surface 111b, and between the scraper 161 and the inner wall surface 111b. The gap T1 can always be kept constant.

  That is, the distance D1 between the axial center O1 of the main shaft 131 and the inner wall surface 111b may not be constant depending on the circumferential position of the inner wall surface 111b due to a manufacturing error of the container 110 or the like. Even in such a case (when the inner wall surface 111b of the container 110 is not a cylindrical surface with high dimensional accuracy), the torque acting on the rotating roller 180 from the inner wall surface 111b with the rotation of the main shaft 131 is the second arm member 182. Is absorbed by swinging (tilting) the neck with respect to the radially outer end 181b of the first arm member 181. In this way, the gap T1 between the scraper 161 and the inner wall surface 111b can always be kept constant, and the scraper 161 can be reliably prevented from coming into contact with the inner wall surface 111b. Can be prevented. Further, since the position of the scraper 161 is set with respect to the inner wall surface 111b using the rotating roller 180, when adjusting the mounting position of the scraper 161, the gap T1 between the scraper 161 and the inner wall surface 111b. Can be adjusted accurately. Since the other effect of 2nd deformation | transformation embodiment is the same as the effect of 1st Embodiment mentioned above, the description is abbreviate | omitted.

6). Paste Kneading Device According to Second Embodiment FIG. 12 is a schematic cross-sectional view showing a paste kneading device 200 according to the second embodiment. The thin film forming means 260 of the paste kneading apparatus 200 includes a dam plate 261 as a holding member and a support member 262 that supports the dam plate 261. Here, FIG. 13 is a cross-sectional view seen from the direction 13-13 shown in FIG. 12, and FIG. 14 is an enlarged view of the Y portion shown in FIG. FIG. 13 shows a state where the paste 270 is omitted.

  As shown in FIGS. 12 and 13, the dam plate 261 has a truncated cone shape having a tapered surface portion 261 a and not having an upper surface portion and a bottom surface portion. The barrier plate 261 is disposed at a position above the liquid level LF of the paste 260, and is supported by four support members 262 at equal intervals in the circumferential direction at the upper end portion of the tapered surface portion 261a. A gap T5 is formed between the lower end of the tapered surface portion 261a and the inner wall surface 211b of the container main body 211. The gap T5 is set to 2 mm, for example. Each support member 262 extends obliquely downward from the inner wall surface 211 b of the container body 211 toward the main shaft 231, and an upper end portion is connected to the inner wall surface 211 b of the container body 211.

  Thus, as shown in FIG. 14, the barrier plate 261 holds a predetermined amount of the paste 270 fed from the inflow port 211c by the sending means 250, and drops the held paste 270 from the gap T5 by gravity. ing. The paste 270 dropped from the gap T5 forms a thin film 271 along the entire inner wall surface 211b of the container 211 above the liquid level LF of the paste 270. As a result, the bubbles positively float on the interface of the thin film 271 and the defoaming of the paste 270 can be effectively promoted. Since the other configuration of the second embodiment is the same as the configuration of the first embodiment, the corresponding parts are denoted by reference numerals in the 200s and the description thereof is omitted.

  The effect of the paste kneading apparatus 200 according to the second embodiment will be described with reference to FIG. FIG. 15 is a diagram comparing the Fe (iron) increase amount I of the paste when defoaming is performed by different methods. This means that the smaller the Fe increase amount I, the smaller the amount of foreign matter (such as iron, which is the material of the container) mixed into the paste, and the better the state of the prepared paste is. In other words, when producing a high-hardness paste containing a hard material, there is a risk that the wear on the inner wall surface will increase. This means that the smaller the amount of increase in Fe, the smaller the wear on the inner wall surface, which is suitable for making a paste with high hardness.

  In FIG. 15, U1 shows the Fe increase amount I of the paste that has been kneaded and stirred using a conventional paste kneader and then defoamed using a centrifugal vacuum deaerator. In this case, the Fe increase amount I is 2 ppm, and the wear on the inner wall surface is relatively small.

  In U2, the Fe increase I of the paste 170 defoamed by the formation of the thin film 171 after kneading and stirring using the paste kneading apparatus 100 according to the first embodiment is shown. In this case, the Fe increase amount I is 0.4 ppm, and the wear of the inner wall surface 111b is small. This is based on the following reason. As shown in FIG. 5, according to the paste kneading apparatus 100 of the first embodiment, the scraper 161 applies a shearing force to the paste 170 (thin film 171) interposed in the gap T1, so that the inner wall surface 111b is worn. This situation is likely to occur. However, since the spacer 162 defines the gap T1 and reduces the contact area with the inner wall surface 111b, wear of the inner wall surface 111b can be reduced. For this reason, in paste kneading apparatus 100, Fe increase amount I becomes a small value of 0.4 ppm.

  In U3, the Fe increase amount I of the paste 270 defoamed by forming the thin film 271 after kneading and stirring using the paste kneading apparatus 200 according to the second embodiment is shown. In this case, the Fe increase amount I is 0.1 ppm, and the wear of the inner wall surface 211b is extremely small. This is based on the following reason. As shown in FIG. 12, according to the paste kneading apparatus 200 of the second embodiment, a shear force does not act on the thin film 271 formed on the inner wall surface 211b, and wear of the inner wall surface 211b is extremely difficult to occur. It is. In other words, in the second embodiment, the thin film 271 is formed in a static situation where no shear force acts, whereas in the first embodiment, the thin film 171 is formed in a dynamic situation where the shear force acts. Is done. For this reason, the Fe increase amount I becomes a very small value of 0.1 ppm. Therefore, this paste kneading apparatus 200 can make it difficult for foreign matter due to wear to be mixed into the paste, and is suitable for producing a paste with high hardness according to the paste composition (material, solid content concentration). Other functions and effects of the second embodiment are the same as the functions and effects of the first embodiment, and a description thereof will be omitted.

7). Paste Kneading Device According to Modified Embodiment of Second Embodiment FIG. 16 is a schematic cross-sectional view showing a paste kneading device 200A according to a modified embodiment of the second embodiment. The thin film forming unit 260A of the paste kneading apparatus 200A includes a dam plate 263 as a holding unit and a support member 262 that supports the dam plate 263. Here, FIG. 17 is a cross-sectional view seen from the direction 17-17 shown in FIG. 16, and FIG. 18 is an enlarged view of the Z portion shown in FIG. Note that FIG. 17 shows a state where the paste 270 is omitted.

  As shown in FIGS. 16 and 17, the dam plate 263 includes a first tapered surface portion 263 a and a second tapered surface portion (extending portion) 263 b. The barrier plate 263 is disposed at a position above the liquid level LF of the paste 260, and is supported by the four support members 262 at equal intervals in the circumferential direction at the upper end portion of the first tapered surface portion 263a. A gap T5 is formed between the lower end of the first tapered surface portion 263a and the inner wall surface 211b of the container body 211. The gap T5 is set to 2 mm, for example. The second tapered surface portion 263b extends in the vertical direction, and the upper end of the second tapered surface portion 263b and the upper end of the first tapered surface portion 263a are connected.

  Thus, as shown in FIG. 18, the dam plate 263 holds a predetermined amount of the paste 270 fed from the inflow port 211c by the sending means 250, and drops the held paste 270 from the gap T5 by gravity. The two taper surfaces 263b are dropped. Since the other configuration of this modified embodiment is the same as that of the second embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  The effect of the paste kneading apparatus 200A according to the modified embodiment of the second embodiment will be described. The paste 270 dropped from the gap T5 forms a thin film 271 along the entire inner wall surface 211b of the container 210 above the liquid level LF of the paste 260. Further, the paste 270 falling along the second tapered surface portion 263b forms the second thin film 272 on the entire second tapered surface portion 263b. Therefore, the bubbles actively float to the interface of the second thin film 272 in addition to the interface of the thin film 271. As a result, the paste kneading apparatus 200A according to this modified embodiment increases the defoaming effect (defoaming effect) by increasing the amount of a paste thin film that can be formed as compared with the paste kneading apparatus 200 according to the second embodiment. Less time). Other functions and effects of this modified embodiment are the same as the functions and effects of the second embodiment, and thus description thereof is omitted.

8). Paste Kneading Device According to Third Embodiment FIG. 19 is a schematic sectional view showing a paste kneading device 300 according to the third embodiment. This paste kneading apparatus 300 includes a kneading apparatus 400 and a defoaming apparatus 500. The kneading apparatus 400 kneads and stirs the paste 470A and has the same configuration as the conventional paste kneading apparatus. That is, the kneading apparatus 400 is an apparatus in which the paste kneading apparatus 100 according to the first embodiment is not provided with the feeding unit 150 and the thin film forming unit 160 that are circulation devices. In the kneading apparatus 400, the paste 470A is kneaded and stirred by the rotation of the desper blade 420 and the anchor blade 430, and then the paste 470 containing many bubbles is fed to the defoaming device 500 through the sending means 550. It has become. Since the other structure of the kneading apparatus 400 is the same as that of the paste kneading apparatus 100 according to the first embodiment, the corresponding parts are denoted by reference numerals in the 400s and the description thereof is omitted.

  The defoaming apparatus 500 includes a delivery unit 550 outside the container 510 (the container according to the present invention), and a thin film forming unit 560 inside the container 510. The container 510 is different from the container (kneading container) 410 of the kneading apparatus 400 in which the paste 470 is kneaded and stirred, and is a thin film forming container for forming a thin film on the inner wall surface 511b. The delivery means 550 feeds the entire amount of the paste 470 from the discharge port 411a of the kneading apparatus 400 (kneading container 410) to the inlet 511c provided in the container main body 511. Here, the paste 470 fed from the kneading device 400 to the defoaming device 500 is referred to as a paste 570. The inflow port 511 c is a hole that is located above the liquid level LF of the paste 570 and is formed in the peripheral wall of the container body 511. The delivery unit 550 includes a delivery pipe 551 and a delivery pump 552. Note that the defoaming apparatus 500 is not an apparatus for kneading the paste 570 and therefore does not have a desper blade.

  The thin film forming means 560 forms a thin film 571 along the inner wall surface 511b of the container main body 511 with respect to the paste 570 fed from the inflow port 511c. Since the configuration of the thin film forming unit 560 is the same as that of the thin film forming unit 160 according to the first embodiment, the corresponding parts are denoted by reference numerals in the 500th order, and description thereof is omitted. Note that the inside of the container 510 is decompressed by the decompression device 440 or another decompression device.

  By the way, in the paste kneading apparatus 100 according to the first embodiment which is a batch type, the paste 170 in the vicinity of the discharge port 111a is sent from the discharge port 111a to the inflow port 111c by the sending means 150 which is a circulation device. ing. However, when processing a high-viscosity paste 170 having a viscosity ν of about 10,000 mPa · s, bubbles generated in the peripheral portion of the main shaft 131 (the R portion indicated by the phantom line in FIG. 5) Since it is high, it does not move from the peripheral portion of the main shaft 131 and tends to remain. For this reason, the remaining foam does not reach the discharge port 111a and does not reach the interface of the thin film 171 formed on the inner wall surface 111b. Therefore, when processing the high-viscosity paste 170, the paste 170 located in the peripheral portion of the main shaft 131 is likely to foam, and the defoaming effect may be reduced.

  On the other hand, in the paste kneading apparatus 300 according to the third embodiment which is a one-pass type, all the paste 470 in the container body 411 of the kneading apparatus 400 is defoamed from the discharge port 411a by the delivery means 550. It is sent to the inflow port 511c. Thereby, the thin film forming means 560 of the defoaming apparatus 500 forms the thin film 571 along the inner wall surface 511b for all the pastes 470 (570) in the container main body 411. For this reason, bubbles generated around the main shaft 431 can reach the interface of the thin film 571. Therefore, even when the high-viscosity paste 470 (570) is processed, the paste 470 (570) located in the peripheral portion of the main shaft 431 can be defoamed, and a reduction in the defoaming effect can be prevented.

  Here, FIG. 20 is a diagram comparing defoaming effects when the paste kneading apparatus 100 according to the first embodiment and the paste kneading apparatus 300 according to the third embodiment are used. FIG. 20 shows the grain gauge reading Q (measured value of grain size) of the paste when the same paste is defoamed by a different method.

  In FIG. 18, V <b> 1 indicates a grain gauge reading Q when a low-viscosity paste is defoamed when the paste kneading apparatus 100 according to the first embodiment is used. Further, in V2, the grain gauge reading Q when the high-viscosity paste is defoamed when the paste kneading apparatus 100 is used is shown. V1 has a grain gauge reading Q of 50 μm, whereas V2 has a grain gauge reading Q of 60 μm, and the paste kneading apparatus 100 has a low defoaming effect when processing a highly viscous paste. I understand.

  On the other hand, in FIG. 20, in W1, the grain gauge reading Q when the low-viscosity paste is defoamed when using the paste kneading apparatus 300 according to the third embodiment is shown. Further, in W2, when the paste kneading apparatus 300 is used, the grain gauge reading Q when the high-viscosity paste is defoamed is shown. In W1 and W2, since the grain gauge reading Q is 50 μm, it can be seen that the paste kneading apparatus 300 can prevent the defoaming effect from being lowered even when a high-viscosity paste is processed. Other functions and effects of the third embodiment are the same as the functions and effects of the first embodiment, and a description thereof will be omitted.

9. Paste Kneading Device According to Modified Embodiment of Third Embodiment FIG. 21 is a schematic cross-sectional view showing a paste kneading device 300A according to a modified embodiment of the third embodiment. This paste kneading apparatus 300A includes a kneading apparatus 400, a first defoaming apparatus 600, and a second defoaming apparatus 700. Since the configuration of the kneading apparatus 400 according to this modified embodiment and the configuration of the kneading apparatus 400 according to the third embodiment are the same, the description thereof is omitted.

  The first defoaming device 600 includes a delivery unit 650 outside the container 610 (the container according to the present invention), and a thin film forming unit 660 inside the container 610. The sending means 650 feeds the entire amount of the paste 470 from the outlet 411a of the kneading apparatus 400 (kneading container 410) to the inlet 611c provided in the container main body 611. Here, the paste 470 sent from the kneading device 400 to the first defoaming device 600 is referred to as a paste 670. The inflow port 611 c is a hole that is located above the liquid level LF of the paste 670 and is formed in the peripheral wall of the container body 611. The delivery means 650 may have the same configuration as the delivery means used conventionally, and has a delivery pipe 651 and a delivery pump 652.

  Since the first defoaming device 600 is not a device for kneading and stirring the paste 670, it does not have a desper blade or an anchor blade. The container 610 of the first defoaming device 600 includes a buffer tank used for transferring the paste kneaded and stirred before applying the paste to a small tank, and a coating for adjusting the state of the paste before coating. It is a construction tank.

  The thin film forming means 660 forms a thin film 671 along the inner wall surface 611b of the container main body 611 with respect to the paste 670 fed from the inflow port 611c. Since the configuration of the thin film forming unit 660 is the same as that of the thin film forming unit 260 according to the second embodiment, the corresponding portions are denoted by reference numerals of the number 600 and the description thereof is omitted. Since the second defoaming device 700 has the same configuration as that of the first defoaming device 600, the corresponding parts are denoted by reference numerals of the 700th generation, and description thereof is omitted. Note that the inside of the container 610 and the inside of the container 710 are decompressed by a decompression device 440 or another decompression device.

  The effects of the paste kneading apparatus 300A according to the modified embodiment of the third embodiment will be described. The kneading apparatus 400 has the same configuration as a conventionally used paste kneading apparatus. The first defoaming device 600 and the second defoaming device 700 have a simple configuration in which thin film forming means 660 and 760 are provided in a buffer tank, a coating tank, and the like that have been conventionally used. Thus, by forming the thin films 671, 771 using the inner wall surfaces of the buffer tank, the coating tank, etc., the pastes 670, 770 can be defoamed easily and inexpensively. Moreover, in this paste kneading apparatus 300A, since the thin films 671 and 771 are formed in a static state where no shearing force acts, foreign matter due to wear can be extremely difficult to be mixed into the pastes 670 and 770. Other functions and effects of this modified embodiment are the same as the functions and effects of the third embodiment, and thus the description thereof is omitted.

10. Modifications As described above, in the paste kneading apparatus and the battery manufacturing method according to the present invention, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.
For example, the thin film forming means 160 of the first embodiment and the first modified embodiment thereof, and the thin film forming means 560 of the defoaming apparatus 500 of the third embodiment have the spacers 162 and 562, but the spacers 162 and 562 are included. May not be included.
In the modified embodiment of the third embodiment, two defoaming devices (first defoaming device 600 and second defoaming device 700) are provided, but the number of defoaming devices is one or three or more. There may be.
Moreover, in each embodiment and its modified embodiment, although the positive electrode paste was created, you may create a negative electrode paste.
In the battery manufacturing method, the paste kneading apparatus 100 according to the first embodiment is used in the paste kneading step, but the paste kneading apparatus 100A according to the first and second modified embodiments of the first embodiment. , 100B, paste kneading apparatuses 200 and 200A according to the second embodiment and modified embodiments thereof, and paste kneading apparatuses 300 and 300A according to the third embodiment and modified embodiments thereof may be used.
Further, the battery to be manufactured may be a battery having a laminated electrode body that is laminated without winding the positive electrode plate and the negative electrode plate. The battery is not limited to a lithium ion secondary battery, and may be a nickel metal hydride battery, other secondary batteries, or a primary battery.

DESCRIPTION OF SYMBOLS 1 Battery 10 Winding electrode body 20 Positive electrode current collecting plate 30 Negative electrode current collecting plate P, N Positive electrode plate, Negative electrode plate PA, NA Positive electrode compound material layer, Negative electrode compound material layer S, T Separator 100 Paste kneading apparatus 100A, 100B Paste kneading Device 110 Container 111 Container body 111a Discharge port 111b Inner wall surface 111c Inlet 120 Desper blade 130 Anchor blade 131 Main shaft 140 Pressure reducing device 150 Delivery means 160 Thin film forming means 161 Scraper 162 Spacer 170 (170A) Paste 171 Thin film 180 Rotating roller 181 First Arm member 182 Second arm member 200 Paste kneading device 200A Paste kneading device 261, 263 Weir plate 261a Taper surface portion 263a First taper surface portion 263b Second taper surface portion 300 Paste kneading device 300A Paste kneading device 400 Kneading device 50 Deaerator 600 first deaerator 700 second deaerator

Claims (11)

In a paste kneading apparatus provided with a container for storing a kneaded and stirred paste,
The container is provided with an inlet through which the paste flows in above the liquid level of the paste to be stored,
Outside the container, a delivery means for feeding the paste into the inlet is provided,
A paste kneading apparatus characterized in that a thin film forming means for forming a thin film along the inner wall surface of the container with respect to the paste fed from the inlet is provided in the container. In the paste kneading apparatus according to claim 1,
The container is provided with a discharge port for discharging the paste,
The paste kneading apparatus, wherein the delivery means is a circulation device that sends the paste stored in the container from the discharge port to the inflow port. In the paste kneading apparatus according to claim 2,
The container is a kneading container in which paste is kneaded and stirred, and is a thin film forming container in which the thin film is formed. In the paste kneading apparatus according to any one of claims 1 to 3,
In the container, a rotating main shaft and a stirring blade assembled to the main shaft and stirring the paste are provided,
The paste kneading apparatus characterized in that the thin film forming means includes a scraper that is assembled to the main shaft or the stirring blade and thins the paste fed from the inlet. In the paste kneading apparatus according to claim 4,
The thin-film forming means includes a spacer that is assembled to the scraper and is in contact with the inner wall surface of the container and that defines a gap between the scraper and the inner wall surface of the container. . In the paste kneading apparatus according to any one of claims 1 to 3,
In the container, a rotating main shaft is provided,
The thin film forming means includes
A rotating roller that rotatably contacts the inner wall surface of the container;
A first arm member assembled to the main shaft and extending in a radial direction with respect to an axial center of the main shaft;
The rotation roller extends in the radial direction with respect to the shaft center of the main shaft and is rotatably supported at the radially outer end portion, and is assembled to the first arm member so as to be tiltable at the radially inner end portion. Two arm members;
A paste kneading apparatus, comprising: a scraper that is assembled to the second arm member and thinly extends the paste fed from the inlet. In the paste kneading apparatus according to any one of claims 1 to 3,
The thin film forming means is a holding member that holds the paste fed from the inlet and forms a gap with the inner wall surface of the container and drops the held paste from the gap. Paste kneading equipment. In the paste kneading apparatus according to claim 7,
The holding member has an extending portion extending in a vertical direction, and the held paste is dropped along the extending portion to form a second thin film of the paste. . In the paste kneading apparatus according to claim 1 or 2,
The container is different from a kneading container in which paste is kneaded and agitated, and all pastes kneaded and agitated from the kneading container are fed into the inlet by the delivery means. A paste kneading apparatus. In the paste kneading apparatus according to any one of claims 1 to 9,
A paste kneading apparatus, wherein a decompression device for reducing the pressure in the container is provided outside the container. A paste kneading step of creating a paste kneaded and stirred from a paste material using the paste kneading apparatus according to any one of claims 1 to 10;
The paste is applied to the electrode core material to form a paste layer and the paste layer is dried to form a positive electrode plate or a negative electrode plate,
An electrode body creating step of laminating or winding the positive electrode plate and the negative electrode plate with a separator interposed therebetween to form an electrode body;
A battery assembly step of disposing the electrode body inside the battery container and injecting an electrolyte into the battery container and sealing the battery body.

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