JP2013157121A - System and method of assembling electrode assembly for secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system capable of shortening a liquid injection time of a secondary battery.SOLUTION: A system 100 of manufacturing a secondary battery is provided. This system 100 comprises: an assembling unit 110 assembling an electrode assembly 2 for a secondary battery by laminating a positive electrode plate 21 and a negative electrode plate 22 so as to be overlapped with each other via a separator 25; and a plasma processing unit 10 using at least any one of the positive electrode plate 21, the negative electrode plate 22, and the separator 25 before assembled to the electrode assembly 2 as a target, and processing the target outside a high-frequency electric field with a gas 16 containing a component turned to plasma by the high-frequency electric field between counter electrodes.

Description

  The present invention relates to a system and method for assembling an electrode assembly for a secondary battery in which a positive electrode plate and a negative electrode plate are laminated so as to overlap each other via a separator.

  In Patent Document 1, the battery case is evacuated to a degree of vacuum within the range of −70 kpa to −95 kpa below the boiling point of the organic electrolyte, and a liquid injection hopper into which a predetermined amount of the organic electrolyte is injected. A step of evacuating the temporary storage chamber to a degree of vacuum in which a pressure difference higher than the pressure in the battery case by 0.1 kpa to 5 kpa is generated, and an organic electrolyte in the temporary storage chamber by opening the injection port of the injection hopper A method for injecting a lithium secondary battery is disclosed, which includes a step of injecting into a battery case via an injection port and an injection nozzle connected to the injection port by a pressure difference.

  Patent Document 2 discloses a method for producing a winding type electrode laminate and an electrode laminate for a lithium ion secondary battery thereby. The present invention relates to a winding method in which electrodes are arranged so as to face both surfaces of a separator whose tension is maintained in both directions, and the electrodes are laminated by a method in which the electrodes are rotated to further form a separator outside the electrodes. Provided are an electrode lamination method, an electrode laminate for a lithium ion secondary battery produced thereby, and a secondary battery using the same. The lithium ion secondary battery according to the present invention is a uniform stress applied to the entire surface of the battery, and as a result of the separator that maintains constant tension, the arrangement of the positive electrode and the negative electrode is not disturbed, thereby extending the life of the battery, Input and output characteristics can be enhanced.

  Patent Document 3 discloses a manufacturing apparatus and method for a rectangular battery electrode plate group in which positive and negative electrode plates are alternately stacked so that a separator is interposed between positive and negative electrode plates. In this manufacturing apparatus and method, a plurality of guide rods are arranged in a zigzag shape in one direction, a continuous body of separators is inserted between one row of the guide rods and the other row, and the guide rods are connected to each other. The continuum is zigzag-folded by crossing one or more pairs in order from the beginning to the tail of the row, and positive and negative plates are inserted alternately into the valley grooves of the continuum in synchronization with this zigzag fold. Then, the guide rod is removed from each trough of the continuum, and then the continuum is pressed flat in a zigzag direction. The electrode plate group can be manufactured with high accuracy by smoothly running the continuum without meandering.

  In Patent Document 4, in order to establish a mass production technology for a stacked lithium ion battery, a technology and a manufacturing device for efficiently producing a bag-shaped electrode plate and a single cell laminated body in large quantities and a mass production are possible. However, it is described that a low-cost self-discharge rate and a good quality laminated lithium ion battery are provided. In Patent Literature 4, a “cradle” and a “presser plate” with a plurality of suction plates that circulate and move, a “cradle” that sucks and fixes the lower separator cut piece and a “presser” that sucks and fixes the upper separator cut piece. While the plate is sandwiched between the electrode plates (positive electrode plates), the upper and lower separators of the electrode plates are automatically heat-bonded at the outer periphery, cut, and surplus. The stacked lithium-ion battery cells are automatically stacked in large quantities by alternately laminating the bare electrode plates (negative electrode plates) opposite to the bag-made electrode plates (positive electrode plates) made by removing the separators The production of a laminate is described.

  Patent Document 5 describes providing a manufacturing method of a battery electrode plate that prevents the loss of an electrode active material and contributes to an improvement in battery capacity. The manufacturing method of the positive electrode plate of patent document 5 is the binder in the positive electrode mixture apply | coated to the cutting part, after apply | coating the positive electrode mixture which mixed the positive electrode active material, the electrically conductive agent, and the binder to the positive electrode side collector. An application step of applying the binder solution along the cutting pattern so that the concentration of the binder is relatively higher than the concentration of the binder in the positive electrode mixture applied to the non-cutting portion; The positive electrode mixture and the binder solution applied to the body were dried to remove the solvent component, the compression step to compress the positive electrode mixture to a predetermined density, and the positive electrode mixture were applied. And a cutting step of cutting the positive electrode side current collector into a predetermined shape.

  Patent Document 6 discloses a method of manufacturing an electrode plate for a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte using the electrode plate for preventing a sharp burr generated at the peripheral edge of the cross section of the electrode plate after cutting. Providing a secondary battery is described. In the manufacturing method of Patent Document 6, after cutting a wide electrode plate into a plurality of narrow electrode plates with a cutting blade in a slitter that conveys the wide electrode plate through a plurality of guide rolls, By pressing only both edges with a pressing roll, sharp burrs generated at the peripheral edge of the cross section of the electrode plate after cutting are remarkably suppressed, and as a result, a non-aqueous electrolyte secondary battery excellent in safety can be obtained. It is described that it can be provided.

JP 2008-59973 A JP 2011-3518 A JP 2009-140775 A JP 2007-329112 A JP 2006-54115 A JP 2008-176939 A

  In the manufacturing process of the secondary battery, an electrode assembly (battery laminate) including the electrode material manufactured by the above-described method or the like is placed in the battery container, and then an electrolytic solution is injected into the battery container. In order to improve the productivity of the secondary battery, it is important to shorten the time for injecting the electrolytic solution into the battery container and shorten the time for the electrolytic solution to penetrate into the electrode material. On the other hand, when the electrolytic solution is put into the battery container, the electrode material of the electrode assembly is treated to promote the penetration of the electrolytic solution, so that the electrode material is damaged or the properties of the electrode material are changed. In such a case, there is a possibility that the performance of the manufactured secondary battery is reduced.

  One embodiment of the present invention is an assembly unit that assembles an electrode assembly for a secondary battery by stacking a positive electrode plate and a negative electrode plate so as to overlap each other via a separator, and a positive electrode before being incorporated into the electrode assembly Using at least one of a plate, a negative electrode plate, and a separator as a target object, the target object is outside the high-frequency electric field with respect to the target object by a gas (hereinafter referred to as a reactive gas) containing a component that is converted into plasma by a high-frequency electric field between the counter electrodes. And a plasma processing unit for processing.

  The gas (reactive gas) containing the component converted into plasma contains radical species. Therefore, when the plasma processing unit sprays the reaction gas on the object or performs a process of passing the object in the reaction gas, the surface of the object or a part of the surface is modified by the radical species in the reaction gas. It becomes easy to become familiar with the electrolyte. For example, if the binder on the surface of the object contains a lot of hydrophobic materials, some of them change to hydrophilic groups depending on the radical species, and the electrolyte is between the objects, for example, the positive electrode and the separator. It may be easy to penetrate or penetrate during the period. An example of the radical species depends on the carrier gas to be converted into plasma, but oxygen gas, nitrogen gas, hydrogen gas, helium gas, argon gas, and water vapor are radicalized.

  Furthermore, the damage of the target object by a high frequency electric field can be suppressed by processing the target object with plasma-ized reaction gas outside a high frequency electric field. By performing plasma treatment outside the region where the high-frequency electric field affects the object, that is, the region where the high-frequency electric field does not easily affect the object, the possibility that the object is damaged by the high-frequency electric field can be reduced, and the electrode assembly And it can suppress that the performance of the battery containing it deteriorates.

  A typical plasma processing unit that processes an object with a reactive gas outside the high-frequency electric field, that is, outside the region where the high-frequency electric field affects the object is a remote method (downflow method, downstream method). The atmospheric pressure plasma generation device is used, and the reaction gas (down flow plasma) generated by the normal pressure plasma generation device is sprayed onto the object at a distance that is not affected by the high-frequency electric field. The unit is arranged or arranged as follows.

  In order to reduce the distance from the atmospheric pressure plasma generator and to spray a reactive gas with high reforming ability (high activity) on the target, a shield electrode is provided between the atmospheric pressure plasma generator and the target to provide a high-frequency electric field. May be shielded. The counter electrode may be arranged in parallel with the object to change the direction in which the high frequency electric field swells, thereby suppressing the influence of the high frequency electric field on the object. The process with the reactive gas may be a process of spraying the reactive gas on one surface of the object, or may be a process of spraying the reactive gas on both surfaces.

  In a system having a transport unit that transports an object to an assembly unit, the plasma processing unit may include a unit that processes the object being transported by the transport unit. In a system including a stacked unit in which an assembly unit assembles an electrode assembly by winding or zigzag-folding a band-shaped object, the plasma processing unit is a band-shaped object before being wound or folded by the stacking unit. May include a unit for processing. In a system that further includes a roll press unit that roll-forms a band-shaped object and supplies it to an assembly unit, the plasma processing unit may include a unit that processes the band-shaped object output from the roll press unit. In a system further including a cutting unit that cuts an object into a predetermined size and supplies the cutting unit to the assembly unit, the plasma processing unit may include a unit that processes the object cut by the cutting unit.

  One of the other aspects of the present invention is to assemble an electrode assembly for a secondary battery by laminating a positive electrode plate and a negative electrode plate so as to overlap each other via a separator, Treating the object outside the region where the high-frequency electric field affects the object with the reaction gas generated by the high-frequency electric field between the counter electrodes with at least one of the positive electrode plate, the negative electrode plate and the separator as the object. A method comprising: The method may further include placing the electrode assembly in a battery case and injecting an electrolyte. While suppressing damage to the positive electrode plate, the negative electrode plate and the separator, it is possible to shorten the time required for injection and impregnation of the electrolyte.

The block diagram which shows the outline | summary of a secondary battery manufacturing system. The figure which shows an example of an assembly unit. The figure which shows an example of a plasma processing unit. The figure which shows the other example of a plasma processing unit. The figure which shows an example of a preparation unit. The figure which shows the other example of an assembly unit. The figure which shows the further different example of an assembly unit.

  FIG. 1 shows an outline of a secondary battery manufacturing system. The manufacturing system 100 includes an assembly unit 110 that assembles an electrode assembly of a secondary battery, preparation units 210, 220, and 250 that prepare a positive electrode plate 21, a negative electrode plate 22, and a separator 25 to be supplied to the assembly unit 110, and a preparation. A transport unit 400 for transporting the positive electrode plate 21, the negative electrode plate 22 and the separator 25 from the units 210, 220 and 250 to the assembly unit 110, and the electrode assembly 2 assembled by the assembly unit 110 are accommodated in the battery case 5, and the electrolyte solution And a liquid injection unit 300 for injecting 3.

  A typical secondary ion battery is a lithium ion secondary battery (hereinafter, a lithium battery). The secondary battery is not limited to a lithium battery, and includes a positive electrode plate 21, a negative electrode plate 22, and a separator 25 that separates them. The positive electrode plate 21, the negative electrode plate 22, and the separator 25 are assembled by an appropriate method to constitute an electrode assembly (electrode element, battery structure, electrode body) 2. The electrode assembly 2 is housed in a battery case (storage container, package) 5 and further injected with an electrolyte 3 to manufacture a secondary battery.

  One assembling method (manufacturing method) of the electrode assembly 2 is called a zigzag stacking method, and a positive electrode plate 21 and a negative electrode plate 22 cut into a continuous band-like (web-like) separator 25 to a certain standard. Are combined in order of the positive electrode plate 21, the separator 25, and the negative electrode plate 22, and the electrode assembly 2 is manufactured. Another method of assembling the electrode assembly 2 is called a winding method (winding method, winding method), and includes a continuous belt-like positive electrode plate 21, a belt-like first separator 25, a belt-like material. The electrode assembly 2 is manufactured by winding the negative electrode plate 22 and the strip-shaped second separator 25. It is also possible to manufacture the electrode assembly 2 by appropriately combining the zigzag stacking method and the winding method, and several methods have been proposed. One of the different methods of assembling the electrode assembly 2 is called a stacking method, and includes a cut (cut) positive electrode plate 21, a cut separator 25, and a cut negative electrode plate 22. In this method, the electrode assembly 2 is manufactured by alternately laminating.

  The positive electrode plate 21 and the negative electrode plate 22 include a core material (web, current collector, electrode foil) made of a metal foil, and a paste containing an active material applied on the core material. In addition to the active material, the paste may contain a binder and, if necessary, a conductive additive or a thickener. A typical active material (positive electrode active material) of the positive electrode plate 21 is a lithium-containing transition metal oxide (such as lithium cobaltate, lithium manganate, or lithium nickelate). Conductive aids such as carbon black such as acetylene black and graphite, and binders such as polyvinylidene fluoride (PVDF) are mixed as a binder into the positive electrode active material, and N-methyl-2-pyrrolidone is added as necessary. A thing is prepared as a slurry, and the slurry is applied to both sides of a core material such as an aluminum foil and dried. Thereafter, the electrode member is pressed in the thickness direction by passing a core material (electrode member, workpiece) coated with an active material through a roll press including a press roller. Thereby, the active material is densified and the capacity of the battery can be increased. Furthermore, it cuts along a length direction with a cutting machine so that a some strip | belt-shaped electrode member may be formed as needed. Further, the belt-like positive electrode plate is cut into a predetermined size by the assembly method of the electrode assembly 2.

  Typical examples of the active material (negative electrode active material) of the negative electrode plate 22 are graphite and graphite capable of inserting and extracting lithium ions. A slurry is prepared by mixing a negative electrode active material with a rubber binder such as carboxymethyl cellulose or styrene butadiene rubber, and adding and dispersing water as necessary, in the same manner as the method for manufacturing the positive electrode plate 21 described above. Thus, a strip-like or plate-like negative electrode plate 22 is manufactured. A typical separator 25 includes polyethylene, polypropylene, and the like.

  The electrode assembly 2 assembled by the assembly unit 110 is housed in a case (battery case, battery container) 5, and the electrolyte solution 3 is injected into the case by a liquid injection unit (liquid injection device) 300. A typical electrolytic solution 3 is obtained by dissolving lithium hexafluorophosphate or the like in a mixed solvent containing ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), or the like. When the case 5 is filled with the electrolytic solution, the opening of the case 5 is sealed and a lithium ion secondary battery is obtained. In the liquid injection unit 300, it is required to shorten the time for injecting the electrolytic solution 3 into the case 2 (liquid injection time) and the time until the electrolytic solution 3 penetrates into the electrode assembly 2 (impregnation time). .

  FIG. 2 shows the assembly unit 110 and the transport unit 400 of the manufacturing system (manufacturing apparatus) 100. The assembly unit 110 includes a web handling unit (lamination unit) 112 that assembles the electrode assembly 2 by a zigzag stacking method, a web supply unit 114 that supplies a strip-shaped separator 25 to the lamination unit 112, and a predetermined size for the lamination unit 112. A first electrode plate supply unit 115 that supplies the positive electrode plate 21 cut into two pieces, and a second electrode plate supply unit 116 that supplies the negative electrode plate 22 cut into a predetermined size to the laminated unit 112.

  An example of the laminated unit 112 that assembles the electrode assembly 2 by the zigzag stacking method is disclosed in Patent Document 3. The laminated unit 112 is not limited to this. Typical examples of the web supply unit 114, the first electrode plate supply unit 115, and the second electrode plate supply unit 116 include a belt-shaped member sandwiched between rollers or a feeder 40, or a plate-shaped member mounted thereon. It moves in the direction of.

  The assembly unit 110 further includes a strip-shaped separator 25 supplied by the web supply unit 114, a positive electrode plate 21 supplied by the first electrode plate supply unit 115, and a negative electrode supplied by the second electrode plate supply unit 116. A plurality of plasma processing units 10 for spraying a processing gas (down flow plasma) 16 on both surfaces of the plate 22 are included.

  FIG. 3 shows an example of the plasma processing unit 10. This plasma processing unit is a remote system (downstream) disposed opposite to each of the upper surface 20a and 20b (upper surface and lower surface, front surface and back surface) of the positive electrode plate 21, the negative electrode plate 22 and the separator 25 which are the processing object 20. System, downflow system) atmospheric pressure plasma generator (atmospheric pressure plasma generator) 11.

  Each plasma generator 11 includes a reactor 15 including a pair of opposed electrodes 13 and 14, and a power supply 12 that applies a high-frequency high voltage to one electrode 13, and the other electrode 14 is grounded. The reactor 15 includes a gas introduction port 18 to which a carrier gas 19 to be converted into plasma is supplied, and a gas containing components converted into plasma by a high-frequency electric field applied between the counter electrodes 13 and 14 (processing gas, downflow plasma). 16 and an outlet 17 for discharging 16. The pair of electrodes 13 and 14 that turn the carrier gas 19 into plasma is covered with a dielectric 39. The dielectric 39 is made of a material having a high relative dielectric constant, for example, general ceramics or glass, so as to generate stable plasma without causing streamer discharge in the plasma generating portion.

  A high-frequency electric field 38 formed between the pair of electrodes 13 and 14 by the power supply 12 is typically an electric field having a frequency of about 1 to 500 kV / cm and a frequency of about 1 to 150 kHz. When the frequency of the high-frequency electric field 38 is too low, the plasma density is low and a sufficient effect cannot be obtained. Further, when the frequency is too high, arc discharge is likely to occur.

  The carrier gas 19 is a simple substance such as nitrogen gas, oxygen gas, hydrogen gas, or a rare gas such as helium, neon, or argon, a combination thereof, or a mixed gas containing at least one of these, such as carbon dioxide gas, Halogen gas etc. may be included. A typical carrier gas 19 is air (80% nitrogen, 20% oxygen). By changing the composition of the carrier gas 19, the surface treatment state of the object (object to be processed) 20 can be changed. The carrier gas 19 is supplied to the reactor 15 at normal pressure (atmospheric pressure) or slightly higher pressure, and the processing gas 16 containing plasma is released from the reactor 15.

  The plasma processing unit 10 processes the surfaces 20 a and 20 b of the target 20 by passing the target 20 through the processing gas 16 blown from the plasma generator 11. At that time, the processing gas 16 and the target gas 20 are brought into contact with the target object 20 and the processing gas 16 outside the high-frequency electric field 38, that is, outside the region where the high-frequency electric field 38 affects the target object 20. Unlike the planar type plasma processing apparatus, the down flow (downstream) type processing gas 16 can prevent the object 20 from being directly damaged by the high voltage of the reactor 15, for example, damage due to arc discharge or the like. . Furthermore, by subjecting the object 20 to plasma treatment outside the region where the high-frequency electric field 38 affects the object 20, the object 20 can be protected from voltage (surface voltage) induced by the high-frequency electric field 38 and damage caused by the current. Can be protected. One way to avoid or suppress the influence of the high frequency electric field 38 of the reactor 15 is to ensure a distance 37 between the reactor 15 and the object 20. The distance 37 for avoiding the influence of the high-frequency electric field 38 and obtaining the effect of the plasma treatment is in the range of 0.5 to 30 mm. The distance 37 is preferably 1.0 to 25 mm, more preferably 2.0 to 10 mm, and still more preferably 3.0 to 5.0 mm.

  One other method of avoiding or suppressing the influence of the high frequency electric field 38 of the reactor 15 is to place a shield electrode 36 between the reactor 15 and the object 20 to confine the high frequency electric field 38 to the reactor 15 side. It is. Thereby, the damage of the target 20 by the high frequency electric field 38 can be suppressed, and the plasma processing by the processing gas 16 can be promoted.

  FIG. 4 shows one further different method of avoiding or suppressing the influence of the high frequency electric field 38 of the reactor 15. By tilting the electrodes 13 and 14 of the reactor 15 with respect to the object 20 or arranging them parallel to each other, the high-frequency electric field 38 can be confined to the reactor 15 side. Therefore, damage to the object 20 due to the high-frequency electric field 38 can be further suppressed, and plasma processing using the processing gas 16 can be promoted.

  By subjecting the surfaces 20a and 20b of the object 20 to plasma processing with the processing gas 16 by the plasma processing unit 10, the surfaces 20a and 20b and the vicinity thereof can be modified. One effect of the modification is an improvement in wettability, and a part of the hydrophobic groups on the surfaces 20a and 20b of the object 20 are cleaved (molecularly cleaved) by the radical species contained in the processing gas 16, and a hydrophilic group (hydrophilic) This is considered to be due to the formation of a hydrophilic group. The positive electrode plate 21 and the negative electrode plate 22 of the object 20 include a large amount of a hydrophobic composition in the active material and / or the binder. The separator 25 is also often hydrophobic. Therefore, when the electrode assembly 2 assembled using these objects 20 is stored in the battery case 5 and then injected with the electrolyte solution 3 in the liquid injection device 300, the electrode assembly 2 is combined with the electrolyte solution 3. It takes a long time to get used to it, which is a factor in increasing the injection time. There is a possibility that the injection time can be shortened by modifying the surface of the object 20 by plasma treatment.

  In addition, it is known that the hydrophilic functional group formed by the surface modification has an aging effect of recombining with moisture in the air and the like due to a change with time to lower the hydrophilicity. Therefore, in order to obtain the effect of modification by the plasma treatment, it is preferable to shorten the time from the plasma treatment to the start of liquid injection as much as possible.

  Further, since the processing gas 16 containing the plasma component contains the ion species as well as the radical species, it has a charge eliminating effect. Therefore, the influence of static electricity or surface potential when assembling the electrode assembly 2 with the object 20 in the laminated unit 112 can be suppressed. When the down flow type plasma (processing gas) 16 is blown onto the object 20, the object 20 may be negatively charged although the voltage is about several volts due to the sheath voltage. In order to further reduce the sheath voltage, it is also effective to shift the ion balance in the processing gas 16 in the cancel direction. It is conceivable to shift (asymmetrically) the high-frequency voltage applied to the reactor 15 in the plus or minus direction, or to adjust the component of the carrier gas 19.

  Furthermore, there is a report that the adhesion force or the adhesion force is improved by spraying the down flow type plasma (processing gas) 16 onto the object 20. Therefore, when the electrode assembly 2 is manufactured by alternately stacking the positive electrode plates 21, the negative electrode plates 22, and the separators 25, which are the objects 20, in the stacked unit 112, the positive electrode plates 21, the negative electrode plates 22, Or it can control that the position of separator 25 shifts and the performance of electrode assembly 2 falls.

  In the assembly unit 110 shown in FIG. 2, the plasma processing unit 10 is provided in each of the first and second electrode plate supply units 115 and 116 and the web supply unit 114. Therefore, the positive electrode plate 21, the negative electrode plate 22, and the separator 25 supplied by the respective supply units 114 to 116 are plasma processed by the plasma processing unit 10 immediately before being assembled by the laminated unit 112. For this reason, the surfaces of the positive electrode plate 21, the negative electrode plate 22, and the separator 25 are modified by the plasma treatment, and there is almost no damage due to the plasma treatment. Therefore, the injection time and the impregnation time can be shortened by injecting the electrolytic solution 3 by the injection unit 300 while the modification effect by the plasma treatment is maintained.

  In addition, each of the supply units 114 to 116 can adjust the rotation speed of the roller 40. For this reason, it is possible to control the time (passing speed) during which the positive electrode plate 21, the negative electrode plate 22 and the separator 25 pass through the plasma processing unit 10, and the degree of modification of the respective surfaces of the positive electrode plate 21, the negative electrode plate 22 and the separator 25 can be controlled. In the state where there is no damage and the wettability with respect to the electrolytic solution 3 is high, it can be appropriately controlled so that the effect of the modification can be obtained when the liquid is injected even if aging occurs.

  The transport unit 400 of the secondary battery manufacturing system 100 shown in FIG. 2 includes a first transport line 401 that transports the positive plate 21 cut to a predetermined size to the assembly unit 110, and the negative plate 22 cut to a predetermined size. And a second transport line 402 for transporting the assembly to the assembly unit 110. Further, the transfer unit 400 includes the plasma processing unit 10 provided in each of the transfer lines 401 and 402. Since the configuration of the plasma processing unit 10 is the same as that of the plasma processing unit 10 described above, the description thereof is omitted below. In the secondary battery manufacturing system 100, the positive electrode plate 21 and the negative electrode plate 22 can be subjected to plasma treatment in the same manner as described above when the positive electrode plate 21 and the negative electrode plate 22 are conveyed to the assembly unit 110.

  In this system 100, plasma processing may be performed by both the transport unit 400 and the assembly unit 110, or plasma processing may be performed by either one of the units. Considering the aging effect, it is desirable to perform the plasma processing in the assembly unit 110 close to the final process of the electrode assembly 2. However, the assembly unit 110 is likely to have a complicated mechanism like the stacked unit 112, and it may be difficult to secure an area where the plasma processing unit 10 can be installed. In such a system, it is effective to provide the plasma processing unit 10 in the transport unit 400 and perform plasma processing on the object 20 (the positive plate 21, the negative plate 22, or the separator 25) being transported.

  FIG. 5 shows a schematic configuration of a preparation unit 210 that prepares the positive electrode plate 21 that is transported by the first transport line 401 of the transport unit 400. The preparation unit 210 includes a roll press unit 260 that rolls the strip-shaped positive plate 21 and a cutting unit 270 that cuts the pressed strip-shaped positive plate 21 into a predetermined size. Furthermore, the preparation unit 210 includes a plasma processing unit 10 that performs plasma processing on the strip-shaped positive electrode plate 21 that has been rolled and a plasma processing unit 10 that performs plasma processing on the cut positive electrode plate 21.

  The roll press unit 260 presses the work 29 in a state where the active material (positive electrode active material) 21b is applied to one surface or both surfaces of the core material 21a with a pair of press rollers (press rolls) 261 and 262, The density of the active material 21b is increased. By disposing the plasma processing unit 10 downstream of the roll press unit 260 and upstream of the cutting unit 270, the belt-like positive electrode plate 21 can be continuously subjected to plasma processing. For this reason, the process gas 16 emitted from the plasma processing unit 10 can be efficiently applied to the positive electrode plate 21. On the other hand, the positive electrode plate 21 including the cut surface or edge can be plasma-processed by the plasma processing unit 10 disposed downstream of the cutting unit 270.

  The preparation unit 220 for preparing the negative electrode plate 22 has the same configuration. The preparation unit 250 for preparing the separator 25 is different in configuration in this example because the strip-shaped separator 25 is used in the assembly unit 110. The preparation unit 250 may include a cutting unit that cuts the separator 25 along the longitudinal direction so that the width of the strip-shaped separator 25 becomes a predetermined size, and upstream and / or downstream of such a cutting unit. A plasma processing unit 10 may be provided. In the secondary battery manufacturing system 100, the positive electrode plate 21, the negative electrode plate 22, and the separator 25 may be subjected to plasma processing using all of these plasma processing units 10, and any one of these plasma processing units 10 is used. The positive electrode plate 21, the negative electrode plate 22, and the separator 25 may be subjected to plasma treatment.

  FIG. 6 shows a different example of the assembly unit. This assembly unit 110 is a laminated unit (manufactured by laminating a belt-like positive electrode plate 21 and a belt-like negative electrode plate 22 via a belt-like separator 25, and winding (winding) them to produce the electrode assembly 2 ( Laminating machine) 120. The assembly unit 110 also includes a supply unit 125 that supplies the strip-shaped positive electrode plate 21 to the stacking unit 120, a supply unit 126 that supplies the strip-shaped negative electrode plate 22 to the stacking unit 120, and a strip-shaped separator 25 to the stacking unit 120. A supply unit 114 to be supplied and a plasma processing unit 10 provided in each of the supply units 125, 126 and 114 are included.

  Therefore, also in the secondary battery manufacturing system 100 including the assembly unit 110, the assembly unit 110 can obtain the electrode assembly 2 including the positive electrode plate 21, the negative electrode plate 22, and the separator 25 subjected to the plasma processing. The injection time and impregnation time of the electrolytic solution 3 in the liquid unit 300 can be shortened.

  FIG. 7 shows still another example of the assembly unit. The assembly unit 110 includes a plurality of positive electrode plates 21 cut to a predetermined size and negative electrode plates 22 cut to a predetermined size alternately stacked with a separator 25 cut to a predetermined size. A laminating unit (lamination machine) 130 for manufacturing the electrode assembly 2 including the positive electrode plate 21, the negative electrode plate 22 and the separator 25 is included. In addition, the assembly unit 110 supplies the cut positive electrode plate 21 to the stacking unit 130 by adsorbing or sandwiching the cut positive electrode plate 21 by the handling unit 45 and supplies the cut negative electrode plate 22 by the handling unit 45. Supply unit 136, a supply unit 134 that supplies the cut separator 25 by the handling unit 45, and the object 20 (the positive electrode plate 21, the negative electrode that is conveyed by the handling unit 45 of those supply units 135, 136, and 134. And the plasma processing unit 10 that sprays the processing gas 16 on the back surface of the plate 22 and the separator 25).

  Therefore, also in the secondary battery manufacturing system 100 including the assembly unit 110, the assembly unit 110 can obtain the electrode assembly 2 including the positive electrode plate 21, the negative electrode plate 22, and the separator 25 subjected to the plasma processing. The injection time and impregnation time of the electrolytic solution 3 in the liquid unit 300 can be shortened.

  As described above, the process of manufacturing the secondary battery by the secondary battery manufacturing system 100 is performed by stacking the positive electrode plate 21 and the negative electrode plate 22 with the assembly unit 110 so as to overlap each other via the separator 25. A step of assembling the electrode assembly 2 for use. In the process of manufacturing the secondary battery, before the positive electrode plate 21, the negative electrode plate 22, and the separator 25 are stacked, the plasma processing unit 10 targets at least one of the positive electrode plate 21, the negative electrode plate 22, and the separator 25. The object 20 includes a step of plasma processing the object 20 outside the high-frequency electric field 38. For this reason, in the step of putting the electrode assembly 2 in the battery case 5 and injecting the electrolytic solution 3 in the liquid injection unit 300 after the electrode assembly 2 is assembled, the injection time and / or the impregnation time is reduced. Can be planned.

  The secondary battery manufacturing system 100 described above is only a few examples. For example, the assembly unit 110 uses a strip separator and a cut electrode plate in the same manner as in the zigzag stacking method, and uses the strip separator. It may be wound to assemble an electrode assembly. Further, in the plasma processing unit 10, the processing gas 16 may be simultaneously sprayed on both surfaces of the object 20, or the processing gas 16 may be sprayed on one surface of the object 20, and time is applied to both surfaces of the object 20. The processing gas 16 may be blown at a different position or at a later time.

2 electrode assembly, 3 electrolyte, 5 battery case 10 plasma processing unit 100 secondary battery manufacturing system, 110 assembly unit

Claims (7)

An assembly unit for assembling an electrode assembly for a secondary battery by laminating a positive electrode plate and a negative electrode plate so as to overlap each other via a separator;
At least one of the positive electrode plate, the negative electrode plate, and the separator before being incorporated into the electrode assembly is an object, and the object includes a gas containing a component converted into a plasma by a high-frequency electric field between the counter electrodes. A plasma processing unit for processing the object outside the high-frequency electric field. In claim 1, further comprising a transport unit for transporting the object to the assembly unit,
The plasma processing unit includes a unit for processing the object being transferred by the transfer unit. The assembly unit according to claim 1, wherein the assembly unit includes a stacked unit that assembles the electrode assembly by winding or folding the belt-like object in a zigzag manner,
The plasma processing unit includes a unit for processing the band-shaped object before being wound or folded by the stacked unit. In any one of Claims 1 thru | or 3, it further has a roll press unit which roll-forms the strip | belt-shaped object and supplies it to the said assembly unit,
The plasma processing unit includes a unit for processing the strip-shaped object output from the roll press unit. The cutting unit according to any one of claims 1 to 4, further comprising a cutting unit that cuts the object into a predetermined size and supplies the cut object to the assembly unit.
The plasma processing unit includes a unit for processing the object cut by the cutting unit. Assembling an electrode assembly for a secondary battery by laminating a positive electrode plate and a negative electrode plate so as to overlap each other via a separator;
Prior to the assembling, the high-frequency wave is applied to the object by a gas containing a component that is plasmatized by a high-frequency electric field between the counter electrodes, with at least one of the positive electrode plate, the negative electrode plate, and the separator as an object. Treating the object outside an electric field.   7. The method of claim 6, further comprising placing the electrode assembly in a battery case and injecting an electrolyte.

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