Mixing system for power storage device

Abstract

To provide a mixing system 1 for a power storage device that efficiently homogenizes multiple types of powder.SOLUTION: A mixing system 1 for a power storage device includes a measuring portion 10 that stores multiple types of powder P measured at a predetermined ratio, a supply portion 20 that is arranged below the measuring portion 10 and supplies the powder P to a kneading portion 30, and the kneading portion 30 that is connected to the supply portion 20 and kneads the powder P supplied from the supply portion 20. The measuring portion 10 includes a lower opening 10c that opens downward, a shutter 11 that is arranged at an opening edge 10d of the lower opening 10c, and a control portion 13 that opens and closes the lower opening 10c by sliding a shutter 11 in an opening / closing direction A. The opening speed, which is the speed at which the shutter 11 moves in the opening direction B, is set on the basis of the volume ratio of the powder P in each of multiple compartments obtained by dividing the powder P stored in the measuring portion 10 into multiple compartments in the opening / closing direction A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a kneading system for an electricity storage device. [Background technology]

[0002] Conventionally, electrodes for electricity storage devices such as lithium ion secondary batteries and lithium ion capacitors have been manufactured by mixing multiple types of powders, kneading the mixed powders with a solvent to form an electrode paste, applying this electrode paste to a metal foil such as aluminum foil or copper foil, and drying it. It is desirable to mix the multiple types of powders in advance prior to kneading to make the composition uniform.

[0003] A kneading system used in the above-described electrode manufacturing is known from Patent Document 1. In this kneading system, a supply device measures out multiple materials, and a transport robot transports a container containing the measured materials from the supply device to the kneading device. In the process of transporting the container from the supply device to the kneading device, the transport robot performs a stirring operation by rotating or shaking the container containing the multiple materials. This mixes the multiple materials contained in the container. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-44487 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described mixing system, the transport robot rotates or shakes the container while transporting the container from the supply device to the kneading device. Therefore, the container cannot be transported from the supply device to the kneading device over the shortest distance with the minimum number of movements. As a result, there is a problem that the electrode manufacturing efficiency is reduced.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a kneading system for an electricity storage device that efficiently homogenizes multiple types of powder. [Means for solving the problem]

[0007] One aspect of the present invention is a measuring unit that stores a plurality of types of powder contained in an electrode paste of an electricity storage device in a state where the powder is measured at a predetermined ratio; a supply unit disposed below the measuring unit and configured to supply the powder to the kneading unit; a kneading unit connected to the supply unit and kneading the powder supplied from the supply unit, The measuring unit is a lower opening that opens downward; a shutter disposed on an opening edge of the lower opening; a control unit that opens and closes the lower opening by sliding the shutter in an opening / closing direction that intersects with the up-and-down direction, In the measuring section, when the shutter is closed, the plurality of types of powder are stored in layers according to type, In a kneading system for an electricity storage device, the opening speed, which is the speed at which the shutter moves in the opening direction to open the lower opening, is set based on the volume ratio of the powder in each compartment, which is obtained by dividing the powder stored in the measuring section into multiple compartments in the opening and closing direction. [Effects of the Invention]

[0008] According to one aspect of the present invention, the powder is supplied from the measuring section to the supply section while maintaining the composition in the measuring section, thereby making it possible to homogenize the composition of the powder supplied to the supply section.

[0009] Furthermore, the powder composition can be made uniform by the simple method of moving the shutter, which improves the efficiency of the powder kneading process as a whole. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic view showing a kneading system for an electricity storage device according to a first embodiment. [Figure 2] 3 is a partially enlarged view showing a weighing unit, a shutter, and a hopper according to the first embodiment. FIG. [Figure 3] 1 is a diagram for explaining the shutter opening speed in embodiment 1, where (a) is a plan view of the shutter and powder seen from above, (b) is a side cross-sectional view of the shutter and powder, (c) is a graph showing the volume ratio of powder stored in each compartment, and (d) is a graph showing the set shutter opening speed for each compartment. [Figure 4] 10 is a partially enlarged view showing a state in which a section a is opened downward by opening the shutter in the first embodiment. FIG. [Figure 5] 10 is a partially enlarged view showing a state in which a section d is opened downward by opening the shutter in the first embodiment. FIG. [Figure 6] 10 is a partially enlarged view showing a state in which a section e is opened downward by opening the shutter in the first embodiment. FIG. [Figure 7] 10A and 10B are diagrams for explaining the opening speed of the shutter according to the second embodiment, in which (a) is a plan view of the shutter and the powder as seen from above, (b) is a side cross-sectional view of the shutter and the powder, (c) is a graph showing the volume ratio of the powder stored in each compartment, and (d) is a graph showing the opening speed of the shutter set for each compartment. [Figure 8] 10A and 10B are diagrams for explaining the shutter opening speed in embodiment 3, where (a) is a plan view of the shutter and powder from above, (b) is a side cross-sectional view of the shutter and powder, (c) is a graph showing the volume ratio of powder stored in each compartment, and (d) is a graph showing the set shutter opening speed for each compartment. [Figure 9] FIG. 10 is a plan view showing a shutter and powder according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Embodiment 1) 1. Overview of kneading system 1 for electricity storage devices A kneading system 1 for an electricity storage device according to Embodiment 1 will be described with reference to Figures 1 and 2. The kneading system 1 for an electricity storage device according to this embodiment kneads powder P contained in electrode paste (not shown) to be applied to electrodes (not shown) of an electricity storage device (not shown). The kneading system 1 for an electricity storage device includes a measuring unit 10, a supply unit 20, and a kneading unit 30.

[0012] 2.Measuring part 10 The measuring unit 10 has a side wall 10a that opens upward and downward. The measuring unit 10 may be formed in a cylindrical shape that opens upward and downward, or in a rectangular tubular shape. The measuring unit 10 according to this embodiment is formed in a cylindrical shape. The measuring unit 10 has an upper opening 10b that opens upward and a lower opening 10c that opens downward.

[0013] The weighing unit 10 is placed on a mounting table 12. The mounting table 12 has an opening 12a at a position that overlaps with the lower opening 10c in the vertical direction. The opening 12a is formed at a position that overlaps with the lower opening 10c of the weighing unit 10 in the vertical direction. The inner shape of the opening 12a is the same as or larger than the inner shape of the lower opening 10c.

[0014] A shutter 11 is disposed at the lower end of the side wall 10a. In other words, the shutter 11 is disposed at the opening edge 10d of the lower opening 10c of the side wall 10a. The shutter 11 is formed in a plate shape. The shutter 11 is configured to be slidable in an opening / closing direction A that intersects the vertical direction. This allows the shutter 11 to open and close the lower opening 10c of the weighing unit 10. The shutter 11 in this embodiment moves in the opening / closing direction A by a motor (not shown). In this embodiment, the opening / closing direction A is set to a substantially horizontal direction. The term "substantially horizontal direction" includes the horizontal direction and also includes cases where a direction that is not horizontal can be recognized as a substantially horizontal direction. Note that in this embodiment, the opening direction B in which the shutter 11 opens the lower opening is set to the right in FIG. 2, and the closing direction in which the shutter 11 closes the lower opening 10c is set to the left in FIG. 2. However, the opening / closing direction A is not limited to the horizontal direction and can be set to any direction.

[0015] The weighing unit 10 includes a control unit 13 that slides the shutter 11 in an opening / closing direction A. The control unit 13 includes a CPU (Central Processing Unit), a PLC (Programmable Logic Controller), a storage device, etc. The control unit 13 drives a motor to slide the shutter 11 in an opening direction B or in a closing direction. The control unit 13 also drives the motor to control the opening speed, which is the speed at which the shutter 11 slides in the opening direction B. The motor is not particularly limited and may be a servo motor or a linear motor.

[0016] The multiple types of powder P are introduced into the measuring section 10 through the upper opening 10b of the measuring section 10. The multiple types of powder P are accommodated in the measuring section 10 in layers, one for each component, stacked vertically. However, the powder P may also be introduced into the measuring section 10 through a hole formed in the side wall 10a of the measuring section 10.

[0017] Powder P is introduced into the measuring unit 10 with the shutter 11 closed. When the shutter 11 opens, the introduced powder P flows downward F from the lower opening 10c. As described above, the inner shape of the opening 12a is the same as or larger than the inner shape of the lower opening 10c. As a result, the powder P that has flowed downward F from the lower opening 10c flows further downward F from the opening 12a of the mounting table 12.

[0018] 3.Powder P The multiple types of powder P have different properties. Properties refer to the nature or state of an object. Therefore, even if the chemical composition is the same, if the properties differ due to differences in temperature or particle size, for example, they become materials with different properties.

[0019] The type of powder P in this embodiment is not particularly limited. The number of types is also not particularly limited, and may be two, three, or more types. In this embodiment, a case where three types of powder P are mixed is exemplified. In this embodiment, powder P1, powder P2, and powder P3 are stored in the measuring unit 10 as an example of multiple types of powder P.

[0020] The compositions of the multiple types of powder P are not particularly limited, and any composition ratio can be selected as appropriate. In this embodiment, a case is illustrated in which, among powder P1, powder P2, and powder P3, powder P1 has the highest composition ratio, powder P2 has the second highest composition ratio, and powder P3 has the lowest composition ratio. However, the composition ratios of powder P1, powder P2, and powder P3 are not limited to the above.

[0021] In this embodiment, powder P1 with the highest composition ratio is placed in the bottom layer, powder P2 with the second highest composition ratio is placed above powder P1, and powder P3 with the lowest composition ratio is placed above powder P2. However, the relationship between the order in which powders P1 to P3 are layered and the composition ratios of each of powders P1 to P3 is not limited to the above, and for example, they may be layered in the order of powder P3, powder P2, and powder P1 from the bottom, or they may be layered in another order.

[0022] The electricity storage device is not particularly limited, and any electricity storage device such as a lithium ion secondary battery or a lithium ion capacitor can be selected.

[0023] When manufacturing a positive electrode of a lithium-ion secondary battery, the powder P can be a positive electrode active material, a conductive additive, a binder, etc. As the positive electrode active material, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, etc. can be used alone or in a mixture of two or more. As the conductive additive, acetylene black, ketjen black, etc. can be used alone or in a mixture of two or more. As the binder, polyvinylidene fluoride, etc. can be used. However, the powder P can also contain materials other than those mentioned above.

[0024] When manufacturing a negative electrode of a lithium ion secondary battery, the powder P can be a negative electrode active material, a conductive additive, a binder, etc. The negative electrode active material can be graphite, etc. The conductive additive can be acetylene black, ketjen black, etc., which can be used alone or in a mixture of two or more thereof. The binder can be SBR rubber, polyacrylic acid, etc., which can be used alone or in a mixture of two or more thereof. However, the powder P can also contain materials other than those mentioned above.

[0025] When manufacturing a positive electrode for a lithium ion capacitor, the powder P can be a positive electrode active material, a conductive additive, a binder, or the like. As the positive electrode active material, activated carbon, carbon nanotubes, polyacene, or the like can be used alone or in a mixture of two or more. As the conductive additive, ketjen black, acetylene black, graphite microparticles, graphite microfibers, or the like can be used alone or in a mixture of two or more. As the binder, polyvinylidene fluoride, polytetrafluoroethylene, polyvinylpyrrolidone, polyvinyl chloride, polyethylene, polypropylene, ethylene-propylene copolymer, styrene butadiene rubber, acrylic resin, polyacrylic acid, or the like can be used alone or in a mixture of two or more. However, the powder P can also contain materials other than those listed above.

[0026] When manufacturing the negative electrode of a lithium ion capacitor, the powder P can be a negative electrode active material, a conductive additive, a binder, etc. The negative electrode active material can be graphite, metal oxides such as tin oxide, silicon oxide, or even modified materials such as these with the addition of phosphorus or boron to improve the negative electrode characteristics. Other negative electrode active materials include those with the chemical formula Li 4+x Ti5O 12 Lithium titanate having a spinel structure w, represented by (0≦x≦3), may also be used. Graphite, etc. may also be used. As the conductive additive, acetylene black, ketjen black, etc. may be used alone or in a mixture of two or more. As the binder, SBR rubber, polyacrylic acid, etc. may be used alone or in a mixture of two or more. Here, a material in which a portion of Ti is substituted with an element such as Al or Mg may also be used. Furthermore, as the negative electrode active material, silicon-based materials such as silicon, silicon alloys, SiO, and silicon composite materials may also be used. These may be used alone or in a mixture of two or more. As the conductive additive, ketjen black, acetylene black, graphite fine particles, graphite fine fibers, etc. may be used alone or in a mixture of two or more. As the binder, polyvinylidene fluoride, polytetrafluoroethylene, polyvinylpyrrolidone, polyvinyl chloride, polyethylene, polypropylene, ethylene-propylene copolymer, styrene-butadiene rubber, acrylic resin, polyacrylic acid, etc. may be used alone or in combination of two or more. However, the powder P may contain materials other than those listed above.

[0027] When producing a paste for a positive electrode of an electricity storage device, an example of the composition of multiple types of powder P is, for example, when powder A, powder B, and powder C are mixed, the mass ratio of each of the powders A to C can be, for example, A:B:C = 7.0-8.0:1.1-1.6:0.4-0.9. However, the mass ratio is merely an example and does not limit the mass ratio of the powder P in the paste for a positive electrode. Furthermore, the types of powder P are not limited to three.

[0028] Furthermore, when producing a paste for the negative electrode of an electricity storage device, an example of the composition of multiple types of powder P is, for example, when powder D and powder E are mixed, the mass ratio of the powders D to E can be, for example, 7-9:1-3. However, the mass ratio is merely an example and does not limit the mass ratio of the powder P in the paste for the negative electrode. Furthermore, the types of powder P are not limited to two.

[0029] As described above, when manufacturing an electrode paste for an electrode device, minor components may be contained in a mass ratio of 20% or less. It is desirable to uniformly disperse such minor components in the electrode paste. In particular, when the minor components are conductive, it is preferable to uniformly disperse them in the electrode paste in order to uniformize the conductivity of the electrodes. Therefore, it is desirable to mix the multiple types of powder P as uniformly as possible in advance before kneading them together.

[0030] 4. Supply section 20 The supply unit 20 includes a hopper 21, a supply unit main body 22, and a supply pipe 23. The hopper 21 is disposed below the measuring unit 10 (F). The hopper 21 is formed in a funnel shape that opens upward and downward (F) and widens as it extends upward. The upper end of the hopper 21 is disposed below the lower opening 10c of the measuring unit 10 (F). The outer shape of the upper end of the hopper 21 is larger than the opening edge 10d of the lower opening 10c of the measuring unit 10. As a result, the powder P that flows downward (F) from the lower opening of the measuring unit 10 flows down to the upper end of the hopper 21 and then flows downward (F) along the inner surface of the hopper 21.

[0031] A supply unit main body 22 is disposed below F of the hopper 21. The hopper 21 and the supply unit main body 22 are connected to each other. As a result, the powder P that flows downward F inside the hopper 21 is supplied to the supply unit main body 22.

[0032] The supply unit main body 22 supplies a predetermined amount of powder P to the kneading unit 30. Although not shown in detail, the supply unit main body 22 may include a device such as a screw or gear for supplying the supplied powder P to the kneading unit 30. The supply unit main body 22 may also include a stirring device for stirring the supplied powder P.

[0033] A supply pipe line 23 is arranged below F of the supply unit main body 22. The supply pipe line 23 is connected to the supply unit main body 22. The supply unit main body 22 transports the introduced powder P to the supply pipe line 23.

[0034] The supply pipe 23 is formed in a cylindrical shape that opens upward and downward F. The lower end of the supply pipe 23 is connected to the kneading section 30. As a result, the powder P conveyed to the supply pipe 23 flows down the supply pipe 23 from above to below F and is supplied to the kneading section 30. The supply section 20 then supplies a predetermined amount of powder P to the kneading section 30 within a predetermined time.

[0035] 5. Mixing section 30 The kneading section 30 kneads the powder P supplied from the supply section 20. Although not shown in detail, the kneading section 30 is equipped with a screw, gear, rotor, etc. for kneading the powder P. The screw may be a single-shaft or twin-shaft screw. The kneading section 30 may be of a continuous type or a batch type.

[0036] The powder P is mixed with a solvent and the like in the mixing section 30 to form an electrode paste, which is then discharged to the outside.

[0037] 6. Shutter 11 opening speed 3(a) to 3(d), the opening speed of the shutter 11, which is the speed at which the shutter 11 opens the lower opening 10c of the measuring unit 10, will be described. FIG. 3(a) schematically shows the powder P stored in the measuring unit 10 and the shutter 11. The side wall 10a of the measuring unit 10 is omitted for ease of explanation. The shutter 11 moves in the opening direction B, thereby opening the lower opening 10c of the measuring unit 10 downward F. As described above, the side wall 10a of the measuring unit 10 is formed in a cylindrical shape, and therefore the powder P stored in the measuring unit 10 is formed in a circular shape when viewed from above.

[0038] As shown by the dashed lines in Figure 3(a), the interior of the measuring unit 10 is divided into multiple sections (eight sections in this embodiment) a to h in the opening direction B of the shutter 11. However, the number of sections may be two to seven, or nine or more. Furthermore, in this embodiment, the sections are divided at equal intervals in the opening direction B of the shutter 11. However, the sections may also be divided at unequal intervals in the opening direction B of the shutter 11.

[0039] 3(b) is a schematic side view of the powder P stored in the measuring unit 10. The powder P is stored in a mountain shape when viewed from the side. That is, the height dimension of the powder P from the top surface of the shutter 11 is greatest near the center of the diameter of the measuring unit 10 and decreases as it approaches the side wall 10a. However, the shape of the powder P stored in the measuring unit 10 is not limited to the above and can be formed into any shape.

[0040] 3(c) is a graph in which the vertical axis represents the volume ratio of powder P located above shutter 11 in each section dividing the measuring section 10, and the horizontal axis represents the position in the diameter direction within the measuring section 10. The volume ratio of powder P is smallest in sections a and h, which are located near sidewall 10a of the measuring section 10, and largest in sections d and e, which are located near the center of the measuring section 10. The volume ratio of powder P increases stepwise in the order of section a, section b, section c, and section d, and then decreases stepwise in the order of section e, section f, section g, and section h, from left to right in FIG. 3(c).

[0041] 3(d) shows the opening speed of the shutter 11 set for each of the sections dividing the weighing unit 10. The opening speed of the shutter 11 is set based on the volume ratio of the powder P located above each of the multiple sections. In detail, the opening speed of the shutter 11 is set slower as the volume ratio of the powder P located above each of the multiple sections increases.

[0042] In this embodiment, the opening speed of the shutter 11 is greatest in sections a and h where the volume ratio of the powder P is relatively small, and the opening speed of the shutter 11 is least in sections d and e where the volume ratio of the powder P is relatively large.

[0043] The opening speed of the shutter 11 decreases stepwise in the order of section a, section b, section c, and section d, from left to right in Fig. 3(d) , and increases stepwise in the order of section e, section f, section g, and section h. In Fig. 3(d) , in the region to the left of section a, the opening speed of the shutter 11 is set to change from speed 0 to the opening speed of the shutter 11 set for section a. In Fig. 3(d) , in the region to the right of section h, the opening speed of the shutter 11 is set to change from the opening speed of the shutter 11 set for section h to speed 0. In other words, the opening speed of the shutter 11 is set to be slower at the middle than the speed at the start of opening, and further set to be faster than the middle speed until the shutter finishes opening.

[0044] 7. Opening speed of the shutter 11 and flow state of powder P 4 to 6, the relationship between the opening speed of the shutter 11 and the flow state of the powder P will be described. 4 to 6 schematically show the state in which the powder P stored in the measuring section 10 flows down into the hopper 21.

[0045] FIG. 4 shows a state in which compartment a is open downward F. The volume ratio of powder P stored in compartment a in the measuring section 10 is relatively small. For this reason, the opening speed of the shutter 11 in compartment a is set relatively high. Because the volume ratio of powder P stored in compartment a is relatively small, even at a relatively high opening speed, all of the powder P located above the shutter 11 in compartment a falls downward F and flows down into the hopper 21. As a result, the powder P stored above the shutter 11 in compartment a is supplied to the supply section 20 while maintaining the composition stored in the measuring section 10.

[0046] FIG. 5 shows a state in which section d is open downward F. The volume ratio of powder P stored in section d in the weighing section 10 is relatively large. Therefore, if the shutter 11 is moved in section d at the same speed as the shutter 11 speed set in section a, there is a possibility that powder P stored above the shutter 11 in the next section e will fall before all of the powder P stored above the shutter 11 in section d has fallen. This could result in powder P with a different composition from the powder P stored in the weighing section 10 falling into the hopper 21. In other words, if powder P3 arranged in the top layer of section d does not fall and remains in the weighing section 10, the remaining powder P3 will fall together with powders P1 to P3 stored above the next section e. This could result in the ratio of powder P3 to the powders P1 to P3 falling in section e deviating from the predetermined composition. As a result, there is a concern that the composition of the powder P supplied from the hopper 21 to the supply unit 20 may become non-uniform.

[0047] Therefore, in the present invention, the speed of the shutter 11 is set to be slow in areas where the volume ratio is large. This allows, for example, all of the powders P1 to P3 stored above the shutter 11 in section d to fall. As a result, the powder P that has fallen into the hopper 21 maintains the composition of the powder P stored in the measuring section 10. The powder P that has fallen into the hopper 21 is supplied to the supply section 20 with its composition maintained.

[0048] FIG. 6 shows a state in which section g is open downward F. The volume ratio of powder P stored above the shutter 11 in section g is smaller than the volume ratio of powder P stored above the shutter 11 in section d. For this reason, for example, if the shutter 11 is moved at the shutter 11 speed set in section d, the powders P1 to P3 stored in section g may collapse. As a result, there is a risk that the powders P1 to P3 that were originally scheduled to fall from the weighing unit 10 when the shutter 11 opened in section h may fall from section g. In this case, too, there is a risk that the composition of the powder P that falls into the hopper 21 may differ from the composition of the powder P stored in the weighing unit 10.

[0049] Therefore, in the present invention, when the volume ratio is small, the shutter 11 speed is set to be large. This makes it possible to prevent the powder P stored in the weighing unit 10 from collapsing. As a result, it is possible to prevent the composition of the powder P dropping into the hopper 21 from differing from the composition of the powder P stored in the weighing unit 10.

[0050] As described above, according to the present invention, in each section, the powder P drops into the hopper 21 while maintaining the composition in the measuring section 10, and is then supplied to the supply section main body 22. This makes it possible to homogenize the composition of the powder P supplied to the supply section 20. Note that while the shutter 11 is moving, the powder P is continuously supplied from the measuring section 10 to the kneading section 30 via the supply section 20.

[0051] Furthermore, the composition of the powder P can be made uniform by the simple method of moving the shutter 11, thereby improving the overall efficiency of the kneading work of the powder P. In other words, the composition of the powder P can be made uniform in the measuring section 10 and the supply section 20 (hopper 21, supply section main body 22, and supply pipe line 23) before it can be kneaded in the kneading section 30, so that even if kneading in the kneading section 30 is done for a short time, it is possible to improve and stabilize the quality of the slurry, such as uniformity and viscosity.

[0052] Furthermore, to maintain consistent performance of the electrode paste, it is desirable to uniformly mix minor components contained in the powder P. The present invention can supply powder P of uniform composition to the supply unit 20 by the simple method of dropping powder P from the measuring unit 10 to the supply unit 20. As such, the present invention is effective when the composition contains minor components of 20% by mass or less. However, the minor components may be 15% by mass or less, or even 10% by mass or less, or even 5% by mass or less.

[0053] Furthermore, when the powders P1 to P3 are stored in the measuring unit 10 in a mountain shape when viewed from the side, the volume ratio of the powders P1 to P3 stored above the shutter 11 varies greatly for each of the sections a to h. In such cases, this embodiment is particularly effective.

[0054] (Embodiment 2) Next, a second embodiment will be described with reference to Figures 7(a) to 7(d). The kneading device for an electricity storage unit according to this embodiment differs from the first embodiment in that the upper surface of each layer of powders P1 to P3 stored in the measuring section 10 is flat. Note that, among the symbols used in the second and subsequent embodiments, the same symbols as those used in the previous embodiments represent the same components, etc. as those in the previous embodiments, unless otherwise specified.

[0055] In this embodiment, powder P1 is introduced into measuring unit 10, and then the top surface of powder P1 is leveled using a tool such as a plate or blade. Thereafter, powder P2 is introduced into measuring unit 10, and then the top surface of powder P2 is leveled using a tool such as a plate. Finally, powder P3 is introduced into measuring unit 10, and the top surface of powder P3 is leveled using a tool such as a plate.

[0056] As shown in Fig. 7(a), the lower opening 10c of the measuring unit 10 is formed in a circular shape. Therefore, as shown in Fig. 7(b), the volume ratio of the powder P stored above the shutter 11 in each section is small in the section closer to the side wall 10a and large in the section closer to the center.

[0057] Therefore, in this embodiment, the shutter 11 speed is set relatively high in the sections a and h near the side wall 10a, and relatively low in the sections d and e near the center, thereby making it possible to make the composition of the powder P dropping from the lower opening 10c of the measuring unit 10 uniform for each section.

[0058] (Embodiment 3) 8(a) to 8(d) illustrate a kneading system 1 for an electricity storage unit according to a third embodiment. Although not shown in detail, the measuring section 10 according to this embodiment is formed in a rectangular cylindrical shape. Therefore, the powder P stored in the measuring section 10 is formed in a rectangular shape when viewed from above.

[0059] In this embodiment, the upper surfaces of the powders P1 to P3 stored in the measuring unit 10 are leveled to a flat shape. However, the powders P1 to P3 may be stored in the measuring unit 10 in a mountain shape, as in the first embodiment.

[0060] As shown in FIG. 1(b), in this embodiment, the volume ratio of powder P stored above the shutter 11 in each of the sections a to h is constant. Therefore, the opening speed of the shutter 11 is also set constant in all of the sections a to h based on the volume ratio of the powder P. This makes it possible to make the composition of the powder P supplied from the lower opening 10c of the measuring section 10 to the supply section 20 uniform.

[0061] (Embodiment 4) Next, a kneading system 1 for an electricity storage unit according to a fourth embodiment will be described with reference to Fig. 9. The shutter 11 according to this embodiment includes a first shutter 11a disposed on one side (the right side in Fig. 9) in the opening / closing direction A, and a second shutter 11b disposed on the other side (the left side in Fig. 9). The first shutter 11a and the second shutter 11b are configured in a so-called double-opening form.

[0062] The opening direction B1 of the first shutter 11a is set to the right in Fig. 9. As a result, the first shutter 11a moves in the opening direction B1 to open the lower opening 10c of the supply unit 20.

[0063] On the other hand, the opening direction B2 of the second shutter 11b is set to the left in Fig. 9. As a result, the second shutter 11b moves in the opening direction B2 to open the lower opening 10c of the supply unit 20.

[0064] Other than the above, the embodiment is the same as the first embodiment, so a duplicated explanation will be omitted.

[0065] According to this embodiment, powder P having a uniform composition can be supplied to the supply unit 20 also in the first shutter 11a and the second shutter 11b.

[0066] The present invention is not limited to the above-described embodiments, and can be applied to various embodiments within the scope of the present invention. [Explanation of symbols]

[0067] 1: kneading system, 10: measuring section, 10a: side wall, 10c: lower opening, 10d: opening edge, 11: shutter, 11a: first shutter, 11b: second shutter, 13: control section, 20: supply section, 30: kneading section, a, b, c, d, e, f, g, h: compartments, A: opening / closing direction, B, B1, B2: opening direction, P, P1, P2, P3: powder

Claims

1. a measuring unit that stores a plurality of types of powder contained in an electrode paste of an electricity storage device in a state where the powder is measured at a predetermined ratio; a supply unit disposed below the measuring unit and configured to supply the powder to the kneading unit; a kneading unit connected to the supply unit and kneading the powder supplied from the supply unit, The measuring unit is a lower opening that opens downward; a shutter disposed on an opening edge of the lower opening; a control unit that opens and closes the lower opening by sliding the shutter in an opening / closing direction that intersects with the up-and-down direction, In the measuring section, when the shutter is closed, the plurality of types of powder are stored in layers according to type, A kneading system for an electricity storage device, wherein an opening speed, which is the speed at which the shutter moves in an opening direction to open the lower opening, is set based on the volume ratio of the powder in each of multiple compartments into which the powder stored in the measuring section is divided in the opening and closing direction.

2. The kneading system for an electricity storage device according to claim 1 , wherein the speed of the shutter is set to be slower in a section having a larger volume ratio of the powder.

3. The kneading system for an electricity storage device according to claim 1 , wherein the powder is stored in the measuring section in a mountain shape when viewed from the side.

4. The kneading system for an electricity storage device according to claim 1 , wherein the plurality of types of powders include a minor component having a composition ratio of 20 mass % or less.

5. The kneading system for an electricity storage device according to claim 4 , wherein the minor component has electrical conductivity.

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