JP2007165170A - Method of manufacturing secondary battery and device of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing-injection method of a secondary battery of which productivity is superior by means that an electrolytic solution is injected in a short time into the secondary battery of a state without injection of the electrolytic solution, and in which the electrolytic solution is precisely injected. <P>SOLUTION: In the method, an opening of a battery container 1 in which an electrode group of the secondary battery in a state without injection of the electrolytic solution are housed and an electrolytic solution primary storage tank 4 are connected with an elastomer 3. After the pressure is reduced in the battery container 1 via the electrolytic solution primary storage tank 4, the electrolytic solution is injected via a first step in which a piston type valve 5 of the electric solution primary storage tank 4 is closed and the pressure in the battery container 1 is maintained in a state of reduced pressure, a second step in which quantitative amount of the electrolytic solution is supplied into the electrolytic solution primary storage tank 4, a third step in which the piston type valve 5 is opened while applying centrifugal force on the electrolytic solution and in which the electrolytic solution is injected into the battery container, a fourth step in which the pressure in the battery container 1 and in the electric solution primary storage tank 4 is made into an equilibrium state, and a fifth step in which the pressure in the battery container 1 is reduced via the electrolytic solution primary storage tank 4 interior. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention comprises a strip-like positive electrode plate coated with a positive electrode mixture paint containing at least a positive electrode active material on a positive electrode current collector and a strip-like negative electrode plate coated with a negative electrode mixture paint containing at least a negative electrode active material on a negative electrode current collector. A method for manufacturing a secondary battery in which a separator is interposed between them and an electrode group wound in a spiral shape is inserted into a battery container, an electrolytic solution is injected into the battery container, and then sealed with a sealing body. The present invention relates to a method for manufacturing a secondary battery and an apparatus for manufacturing the same, in which an electrolytic solution is efficiently and efficiently injected into a battery container.

  In recent years, portable and cordless electronic devices such as AV devices, personal computers, and portable communication devices have been rapidly promoted. As drive power sources for these electronic devices and other power sources, load characteristics with high energy density are provided. Therefore, there is a demand for an excellent sealed battery. In particular, lithium batteries having many features such as high energy density and voltage, and long shelf life are in the spotlight.

  For example, in a cylindrical lithium battery, a positive electrode plate and a negative electrode plate are spirally wound through a separator to form an electrode group, and then the electrode group is accommodated in a bottomed cylindrical battery container, A groove is formed in the outer periphery of the opening of the battery container in an annular shape, a predetermined amount of electrolyte is poured into the battery container, and then a sealing body is inserted into the opening of the battery container via a gasket and protrudes inward. The battery container is sealed by caulking the opening of the battery container while the sealing body is supported on the groove.

  In these secondary batteries, in order to increase the capacity of the secondary battery, it is necessary to store as many wound electrode groups as possible in the battery container and a large amount of electrolyte solution corresponding to the electrode groups. However, it has been difficult to efficiently and efficiently inject the electrolytic solution into the battery container.

  As a method of injecting the electrolyte into the battery container, as shown in FIG. 12, the opening of the battery container 101 and the electrolyte temporary storage tank 104 are connected by the packing 103 and then placed on the turntable 106. Then, after depressurizing the inside of the battery container 101, a fixed amount of electrolyte is supplied to the electrolyte solution temporary storage tank 104, and the centrifugal force is applied to the battery container 101 and the electrolyte solution temporary storage tank 104 by rotating the rotating plate 106. Thereafter, the taper pin 105 is opened, and a method of injecting liquid using a pressure difference between the negative pressure in the battery container 101 and the atmospheric pressure in the electrolyte temporary storage tank 104 and centrifugal force has been proposed (for example, Patent Documents). 1).

  Further, as shown in FIG. 13, after the inside of the desiccator container 202 in which the battery container 201 is installed is decompressed, the electrolytic solution is dropped from the discharge nozzle 203 using the pressure difference between the inside and outside of the desiccator container 202 and dropping. Thereafter, a liquid injection method has been proposed in which the dropping of the electrolytic solution is stopped, the inside of the desiccator container 202 is depressurized or pressurized, and the method of removing bubbles generated in the battery container 201 is repeated (for example, see Patent Document 2). ).

Further, as shown in FIG. 14, the battery container 301 is housed in the filling chamber 305, a necessary amount of electrolyte is supplied into the electrolyte temporary storage tank 304, and the lid of the electrolyte temporary storage tank 304 is covered by the piston 303. Then, after reducing the pressure in the filling chamber 305, the piston 303 is lowered to push out the electrolyte from the electrolyte temporary storage tank 304, and the electrolyte is injected from the discharge nozzle 302 into the battery container 301. A method has been proposed in which the filling chamber 305 is pressurized to sufficiently inject the electrolyte into the battery container 301 (see, for example, Patent Document 3).
JP-A-8-106896 JP 2004-22502 A Japanese Patent No. 3467135

  However, in the above-described prior art of Patent Document 1, the taper pin 105 is opened in a state where the centrifugal force is applied as shown in FIG. 12, and the electrolyte is biased by both the centrifugal force and the pressure difference. It is scattered to the surroundings and adheres to the vicinity of the opening of the battery container 101, so that an undesired problem that the required amount of electrolyte cannot be obtained and the battery capacity is insufficient occurs.

  In the prior art of Patent Document 2, as shown in FIG. 13, it takes a long time to completely evacuate the desiccator container 202. In a high vacuum state, the electrolyte is vaporized due to a pressure difference. It splatters on the outer periphery of the battery container 201 and the inner wall of the desiccator container 202, and the problem of the loss of electrolyte solution and the deterioration of injection accuracy occurs. On the other hand, when the pressure is reduced for a short time, the inside of the battery container 201 cannot be sufficiently reduced, and air is confined in the battery container 201 at the time of pouring, and a lot of time is required for pouring the electrolyte.

  Further, in the liquid injection method disclosed in Patent Document 3, the electrolyte can be injected into the battery container 301 in a short time by reducing the pressure and applying pressure by the piston 303 as shown in FIG. The electrolyte that adheres to the inside of the electrolyte temporary storage tank 304 and the piston 303 and the liquid injection path due to surface tension cannot be guided into the battery container 301, and many electrolytes in the temporary storage tank 304 are temporarily stored. It remains attached to the tank 304, and the accuracy of liquid injection deteriorates. In addition, when the pressure is reduced to reduce the pressure inside and outside the battery container 301 and the air in the battery container 301 is taken out under reduced pressure, the electrolyte is vaporized during the differential pressure injection, and the battery container 301 may be scattered on the outer periphery of the battery container 301 or the inner wall of the filling chamber 305. Electrolyte loss occurs, leading to poor injection accuracy. If the degree of vacuum is such that the electrolyte does not evaporate, it is not suitable for injection, leaving air in the battery container 301 and causing a longer injection time.

  The present invention has been made in view of the above-described conventional problems, and when injecting an electrolytic solution into a battery container, it is sealed together with the enclosed container such as a desiccator container in which the battery container is installed while acting a centrifugal force, Instead of creating a vacuum state, the opening of the battery container containing the electrode group and the electrolyte temporary storage tank are joined by an elastic body, and the temporary electrolyte storage tank and the battery container are brought into a vacuum state in a short time. An object of the present invention is to provide a secondary battery manufacturing method and a manufacturing apparatus thereof that can realize high-precision liquid injection, prevent adhesion of an electrolytic solution, and improve liquid injection accuracy.

  In order to achieve the above object, the method for producing a secondary battery according to the present invention includes a positive electrode current collector coated with a positive electrode mixture paint containing at least a positive electrode active material and at least a negative electrode current collector and a belt-like positive electrode plate. An electrode group formed by winding a strip-shaped negative electrode plate coated with a negative electrode mixture paint containing a negative electrode active material in a spiral shape with a separator interposed therebetween is inserted into the battery container, and an electrolytic solution is poured into the battery container. A method for producing a secondary battery that is sealed with a liquid sealing body, wherein an opening of a battery container housing an electrode group and an electrolytic solution temporary storage tank are connected via an elastic body, and the electrolytic solution temporary storage tank is used. After depressurizing the inside of the battery container, close the valve that opens and closes the electrolytic solution storage tank to maintain the inside of the battery container in a depressurized state, and then supply a certain amount of electrolyte into the electrolyte solution storage tank In the second step, and then with centrifugal force acting on the electrolyte A third step of injecting the electrolyte into the battery container, a fourth step of bringing the pressure in the battery container and the electrolyte temporary storage tank into equilibrium, and further through the electrolyte temporary storage tank An electrolyte solution is injected into the battery container through a fifth step of reducing the pressure in the battery container.

According to the present invention, the opening of the battery container containing the electrode group and one storage tank are connected via an elastic body, while the centrifugal force and the pressure in the battery container and the electrolyte temporary storage tank are balanced, By injecting the electrolyte into the battery container, the injection of the electrolyte into the battery container is completed in a short time, and the electrolyte can be injected with high accuracy and less loss.

  In the first aspect of the present invention, a strip-like positive electrode plate coated with a positive electrode mixture paint containing at least a positive electrode active material is applied to a positive electrode current collector, and a negative electrode mixture paint containing at least a negative electrode active material is applied to a negative electrode current collector. An electrode group formed by winding a strip-shaped negative electrode plate in a spiral shape with a separator interposed therebetween is inserted into a battery container, an electrolyte is injected into the battery container, and the secondary battery is sealed with a sealing body. In the manufacturing method, the opening of the battery container housing the electrode group and the electrolyte temporary storage tank are connected via an elastic body, and the inside of the battery container is depressurized via the electrolyte temporary storage tank. The first step of closing the valve for opening and closing the temporary storage tank to maintain the inside of the battery container in a depressurized state, the second step of supplying a fixed amount of the electrolyte into the temporary electrolyte storage tank, and the centrifugal force Open the valve with the electrolyte applied, and inject the electrolyte into the battery container. The battery through the third step, the fourth step of bringing the pressure in the battery container and the electrolyte temporary storage tank into equilibrium, and the fifth step of reducing the pressure in the battery container via the temporary electrolyte storage tank In this method, an electrolytic solution is injected into the container, and by using this method, the electrolytic solution can be injected into the battery container with high accuracy in a short time.

  In the second invention of the present invention, in the third step, the inside of the electrolyte temporary storage tank is depressurized, and the valve is opened in a state where centrifugal force is applied to the electrolyte. It is possible to inject the electrolyte into the battery container with high accuracy while suppressing the scattering of the electrolyte.

  In the third invention of the present invention, in the third step, while applying centrifugal force to the electrolyte, the electrolyte temporary storage tank is brought into a pressurized state, the valve is opened, and the solution is poured into the battery container containing the electrode group. Thus, by doubling the force acting on the electrolytic solution, the electrolytic solution can be injected into the battery container in a short time.

  In the fourth aspect of the present invention, in the third or fourth step, the pressure control in the electrolyte temporary storage tank is increased along a pressure waveform according to a function of a linear straight line or a curve depending on time, The pressure in the battery container containing the group and the electrolyte storage tank is balanced, and the surface of the electrolyte is corrugated by the gas flowing into the electrolyte storage tank at a high speed when pressurized with gas. In addition, it is possible to prevent bubbles from being generated in the liquid surface and in the liquid, and to prevent the bubbles from flowing into the battery container together with the electrolyte and taking time to impregnate the electrode group with the electrolyte in a stable and short time. Can be achieved.

  In the fifth invention of the present invention, the fourth step and the fifth step are repeated a plurality of times to inject the electrolyte into the battery container containing the electrode group, and air bubbles remaining in the battery container The flow rate can be repeatedly applied to the electrode group, and the electrolyte solution can be impregnated into the electrode group, and the electrolyte solution can be injected into the battery container in a short time.

  In the sixth invention of the present invention, the battery container in which the electrode group formed by winding the positive electrode plate and the negative electrode plate in a spiral shape with a separator interposed therebetween and the opening of the battery container are elastic bodies. And a pressure valve connected to the electrolyte temporary storage tank, and a valve connected to open and close the electrolyte temporary storage tank, and a pressure connected to the electrolyte temporary storage tank for sucking and discharging the gas in the battery container and the temporary electrolyte storage tank Adjustment, rotation plate for applying centrifugal force to the electrolyte supplied to the electrolyte temporary storage tank by fixing and rotating the temporary storage tank, a pump for supplying the electrolyte into the electrolyte temporary storage tank, and the electrolyte A pump for depressurizing the inside of the temporary storage tank, a switching valve for switching the pressure inside the temporary storage tank for depressurization, pressurization, and switching to an atmospheric pressure state, and a drive unit and a turntable for opening and closing the valve for opening and closing the temporary storage tank A secondary battery manufacturing apparatus configured with a rotating drive unit, Thereby making it possible to pour an electrolyte solution into time battery container with high accuracy.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. For example, in the secondary battery manufacturing apparatus of the present invention as shown in FIG. 1, the battery container fixing jig 7 and the electrolyte temporary storage tank 4 are disposed on the rotating plate 6, and the rotating plate 6 is installed on the gantry 30. It is connected to the power unit 8 through the bearing 31 that is made to transmit the rotational force to the rotating disk 6. The power unit 8 may be a mechanism directly connected to an electric motor. In the present invention, a servo motor provided with a gear is connected to the rotating disk 6 via a bearing 31.

  The battery container 1 is set on the battery container fixing jig 7 on the turntable 6 so that the packing 3 made of an elastic body such as rubber that keeps airtight even when the pressure in the battery container 1 is reduced and pressurized. To the electrolyte temporary storage tank 4. The battery container fixing jig 7 may be a mechanism capable of chucking the battery container 1 and may be held by a permanent magnet or vacuum suction. In the present invention, the battery container 1 is held by fitting the battery container fixing jig 7 and the packing 3 using the elastic force of the packing 3.

  In addition, by operating a valve drive unit 19 disposed on the turntable 6, the piston type valve 5 built in the electrolyte temporary storage tank 4 is drawn toward the center of the turntable 6, and the battery container 1 and the electrolyte solution are drawn. The temporary storage tank 4 is communicated (hereinafter referred to as “open”). The valve drive unit 19 may be a plate cam that rotates and transmits the drive. In the present invention, a linear motion is transmitted to the piston type valve 5 by an air cylinder.

  A pressure adjusting unit 33 is connected to the electrolyte temporary storage tank 4 via a gas pipe 24, and the pressure adjusting unit 33 includes an atmospheric release two-way valve 13, a waveform control pressure two-way valve 14, a pressure increasing valve 15, and an air generating unit. 11. A pressure reducing two-way valve 16, a weak pressure reducing two-way valve 17, a high vacuum pressure regulator 9, a medium vacuum pressure regulator 10, and a vacuum pump 12 are installed to detect the pressure in the battery container 1 or the electrolyte temporary storage tank 4. While pressurizing or depressurizing. Further, in the present invention, compressed air is used as the gas to be pressurized. However, an inert gas may be used, and the use of the inert gas has a great effect on the electrolyte.

  The electrolyte solution supply section 32 connected to the electrolyte solution temporary storage tank 4 includes an electrolyte solution storage tank 21, a liquid pipe 25, a supply pump 18, and a supply nozzle 20. Supply in.

  Further, instead of the piston type valve 5 in the electrolyte temporary storage tank 4, a ball valve type valve 23 may be used as shown in FIG.

  The battery container 1 may be a bottomed cylindrical or rectangular battery container having an open top. Examples of the material include those obtained by applying nickel plating to a steel plate and those made of an aluminum alloy. After the electrode group 2, which will be described later in detail, is stored in the battery container 1, an annular groove is formed on the outer periphery of the opening 22 of the battery container 1, and the electrode group 2 is held in the battery container 1.

  In the battery container 1 into which the electrolytic solution has been injected, a positive electrode lead (not shown) led out from the electrode group 2 is welded to the battery container 1, and then a negative electrode lead (not shown) led out from the electrode group 2 is used. An insulating gasket is welded to a sealing plate (not shown) provided on the periphery, the sealing plate is inserted into the opening 22 of the battery container, and the opening 22 of the battery container 1 is bent inward to seal by sealing. A secondary battery is manufactured.

Here, in the electrode group 2 housed in the battery container 1, a positive electrode plate using a composite lithium oxide as an active material and a negative electrode plate using natural graphite as an active material are made of a polymer such as polyethylene. The electrode plate group 2 is formed by winding or laminating spirally through a separator that is a microporous film.

  The positive electrode plate is a positive electrode composite in which a positive electrode active material, which is a lithium-containing composite oxide such as lithium cobaltate, a conductive agent using acetylene black, and a binder using polyvinylidene fluoride are kneaded and dispersed in a dispersion medium. An agent paint is applied to an aluminum foil as a positive electrode current collector, dried and rolled to use a strip-shaped positive electrode plate. Although it does not specifically limit about a positive electrode electrical power collector, The thing of 10 micrometers-60 micrometers of thickness which carried out foil or the lath processing or the etching process made from aluminum or aluminum alloy can be used.

  The negative electrode plate is composed of a negative electrode active material using natural graphite, a binder using polyvinylidene fluoride, and a thickener using polyethylene oxide. It is applied to a copper foil, which is an electric body, dried and rolled, and a strip-shaped negative electrode plate is used. The negative electrode current collector is not particularly limited, and a negative electrode current collector made of rolled copper foil, electrolytic copper foil, lath processed or etched copper foil having a thickness of 10 μm to 50 μm can be used.

  As the separator, a multilayer film in which microporous films are stacked is used, and among them, a microporous film made of polyethylene, polypropylene, PVdF, or the like is suitable, and the thickness is preferably 10 μm to 25 μm.

The electrolyte is composed of a nonaqueous solvent containing cyclic carbonates such as ethylene carbonate and propylene carbonate and chain carbonates such as dimethyl carbonate and diethyl carbonate as main components, and lithium having a strong electron withdrawing property such as LiPF ₆ and LiBF _4. Consists of solutes using salt.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A method for manufacturing a secondary battery in Example 1 of the present invention will be described with reference to FIG. In the first step, the valve drive unit 19 arranged on the rotating disk 6 is operated, the piston type valve 5 is opened, the two-way valves 13, 14, 17 of the pressure adjusting unit 33 are closed, The directional valve 16 is opened and the high vacuum pressure regulator 9 and the vacuum pump 12 set to a high vacuum pressure value are operated, so that the pressure in the battery container 1 is about 1.0 kPa or less, which is about 1/100 of the atmospheric pressure. Depressurize for 60 seconds.

  After the pressure reduction for 60 seconds, the valve drive unit 19 is operated to close the piston type valve 5 so that the battery container 1 and the electrolyte temporary storage tank 4 are closed (hereinafter referred to as closing). Next, by closing the pressure reducing two-way valve 16 in the pressure adjusting unit 33 and opening the atmospheric pressure releasing two-way valve 13, the inside of the electrolyte temporary storage tank 4 is maintained while maintaining the inside of the battery container 1 in a reduced pressure state. Release to atmospheric pressure.

  In the second step, the supply nozzle connected to the electrolyte temporary storage tank 4 from the supply pump 18 connected to the electrolyte storage tank 21 in the electrolyte supply part 32 by the liquid pipe 25. A fixed amount of electrolyte is supplied from 20 into the electrolyte temporary storage tank 4. In addition, the electrolyte temporary storage tank 4 at this time was in an atmospheric pressure state, and 5.8 g was supplied as the amount of the electrolyte.

  In the next third step, the power unit 8 is driven, the rotational speed of the rotating disk 6 reaches 1000 rpm, and the predetermined centrifugal force is about 300 G (gravitational acceleration is set to 1 G) on the battery container 1. Then, the valve drive part 19 is operated, the piston type valve 5 is opened, and injection of electrolyte solution is started.

In the fourth step, after the atmospheric pressure releasing two-way valve 13 in the pressure adjusting unit 33 is closed (the two-way valves 16 and 17 are already closed), the pressure of the gas supplied from the air generating unit 11 is changed. The pressure increase valve 15 increases the pressure approximately twice, opens the waveform control pressure two-way valve 14, and opens the electrolyte temporary storage tank 4 as shown in FIG. The pressure in the battery container 1 and the electrolyte temporary storage tank 4 is brought into an equilibrium state with a pressure of 1000 kPa while the pressure is applied gradually while the method of applying is moderated. Further, in Example 1, the pressure was increased along the waveform according to the function of the curve. However, as shown in FIG. 8, the method of applying the pressure into the electrolyte temporary storage tank 4 in the fourth step is linear. The pressure may be 1000 kPa.

  Next, after maintaining the centrifugal force and the pressurized state for 60 seconds, the waveform control pressure two-way valve 14 is closed, the atmospheric pressure release two-way valve 13 is opened, and the pressure in the battery container 1 and the electrolyte temporary storage tank 4 is The pressure in the battery container 1 and the electrolyte solution temporary storage tank 4 is 101.3 kPa.

  Finally, in the fifth step, after the atmospheric pressure release two-way valve 13 is closed in a state where centrifugal force is applied, the weak pressure reduction two-way valve 17 is opened and the battery is operated at 21.3 kPa set by the medium vacuum pressure regulator 10. The container 1 and the electrolyte storage tank 4 are depressurized for 10 seconds. As a result, it is possible to prevent the electrolyte from overflowing again after the injection, and the reduced bubbles in the electrode group 2 pressurized in the fourth step can be sucked out from the electrode group 2.

  Next, the weak pressure reducing two-way valve 17 is closed, the atmospheric pressure release two-way valve 13 is opened, the inside of the battery container 1 and the electrolyte temporary storage tank 4 are brought into the atmospheric pressure state, and the valve driving unit 19 is operated. The piston type valve 5 is closed. Further, the power unit 8 is stopped and the rotation of the rotating disk 6 is stopped, and the fifth step is completed.

  As described above, the first to fifth steps are performed, the battery container 1 which has been injected and impregnated with the electrolyte group 2 to prevent the electrolyte from spilling is taken out, and the battery container 1 is taken as an example. It was set to 1.

  As another embodiment of the present invention, as shown in FIG. 3, a temporary electrolyte storage tank 40 and a transport jig 43 containing the battery container 1 containing the electrode group 2 are configured as a transport type liquid injection section 26. The dosing section 26 is prepared and circulated through the first process, the second process, the third process, the fourth process, and the fifth process. The transport-type liquid injection unit 26 that has completed the process is transferred to the battery container 1 that has not completed the first process and is transported. In this embodiment, the transport type liquid injection unit 26 is transported automatically by a conveyor, but may be transported by a self-propelled machine or transported by a person.

  In the present Example 2, the first process, the second process, and the third to fifth processes of Example 1 described above can be simultaneously performed, and the time required for the liquid injection process can be shortened. Will be described in detail with reference to the drawings. FIG. 3 is a schematic diagram illustrating the state of the first step in the second embodiment. The battery container 1 containing the same electrode group 2 as in the first embodiment is housed in a transport jig 43, and the electrolyte temporary storage tank 40 with a packing 42 and a built-in piston type valve 41 is connected to the transport jig 43. The transport type liquid injection unit 26 that is configured integrally with is transported to the next step.

  In the first step, as shown in FIG. 4, a decompression adjusting unit 35 is connected to the electrolyte temporary storage tank 40 constituting the transport type injection unit 26 through the gas pipe 24, and the valve driving unit 27 is connected to the piston. Connected to the mold valve 41.

Next, the valve drive unit 27 is operated, the piston type valve 41 is opened, and in a state where the battery container 1 and the electrolyte temporary storage tank 40 communicate with each other, the atmospheric pressure release two-way valve 50 in the decompression adjustment unit 35 is closed, Open the pressure reducing two-way valve 51. Further, the high vacuum pressure regulator 52 is set to 1.0 kPa, the vacuum pump 53 is operated, and the inside of the battery container 1 is decompressed for 60 seconds.

  After the pressure reduction for 60 seconds, the valve drive unit 27 is operated to close the piston type valve 41 so that the battery container 1 and the electrolyte temporary storage tank 40 are closed. After closing 51, the atmospheric pressure release two-way valve 50 is opened, and the inside of the electrolyte temporary storage tank 40 is returned to 101.3 kPa, which is the atmospheric pressure, while the inside of the battery container 1 is held in a decompressed state. . The transport type liquid injection unit 26 that has finished the first step is transported to the second step of the next step.

  In the second step, as shown in FIG. 5, the electrolyte supply part 36 constituted by the supply nozzle 56, the electrolyte storage tank 54, and the supply pump 55 is replaced with the electrolyte temporary storage tank 40 in the transport type injection part 26. 5.8 g of a fixed amount of electrolyte solution is supplied from a supply discharge nozzle 56 connected to the electrolyte temporary storage tank 40 from a supply pump 55 connected to the electrolyte solution storage tank 54 by a liquid pipe 64. The electrolyte solution was supplied into the temporary storage tank 40. Next, the supply nozzle 56 is disconnected from the electrolyte temporary storage tank 40, and the electrolyte is kept in the electrolyte temporary storage tank 40, and the battery container 1 is transported to the third process of the next process while being kept in a reduced pressure state. To do.

  In the third step, several tens of transport-type liquid injection units 26 are sequentially installed on the turntable 44, and FIG. 6 is a schematic diagram showing a part thereof. As shown in FIG. Is installed on the turntable 44, the valve drive unit 45 is connected to the piston type valve 41, and the pressure adjustment unit 37 is connected to the transport type liquid injection unit 26 via the gas pipe 65. After the transport type liquid injection unit 26 is set on the rotating plate 44, the power unit 47 is driven, and the rotating plate 44 starts rotating via the bearing unit 46 installed on the gantry 48.

  After the rotation speed of the turntable 44 reaches 1000 rpm and the predetermined centrifugal force reaches about 300 G (the gravitational acceleration is set to 1 G) on the battery container 1, the valve drive unit 45 is operated to change the piston type valve 41. Open and start pouring electrolyte.

  In the fourth step, after the atmospheric pressure release two-way valve 60 in the pressure adjusting unit 37 is closed (the two-way valves 57 and 61 are already closed), the pressure increasing valve 58 supplies the air from the air generating unit 59. The pressure of the gas is increased by a factor of about 2, and the waveform control pressure two-way valve 57 is opened while being controlled, and the inside and outside of the temporary electrolyte storage tank 40 are gradually applied as shown in FIG. However, the pressure is controlled to be a predetermined pressure in 5 seconds, and the pressure in the battery container 1 and the electrolyte temporary storage tank 4 is brought into an equilibrium state in a pressurized state of 1000 kPa.

  Next, after maintaining the centrifugal force and pressurization state for 60 seconds, the waveform control pressure two-way valve 57 is closed, and then the atmospheric pressure release two-way valve 60 is opened, and the battery container 1 and the electrolyte temporary storage tank 40 are opened. Set the pressure inside to atmospheric pressure.

  In the fifth step, the atmospheric pressure release two-way valve 60 is closed in a state where the centrifugal force is applied. Next, the weak pressure reducing two-way valve 61 is opened, the battery container 1 and the electrolyte storage tank 40 are depressurized for 10 seconds at 21.3 kPa set by the medium vacuum pressure regulator 62, and the pressure is increased in the fourth step. Thus, it is possible to suck out only the reduced bubbles in the electrode group 2 and prevent the electrolyte from overflowing again after the injection.

  Next, the weak pressure reduction two-way valve 61 is closed, the atmospheric pressure release two-way valve 60 is opened, the battery container 1 and the electrolyte temporary storage tank 40 are brought into an atmospheric pressure state, and the valve driving unit 45 is operated to operate the piston. The mold valve 41 is closed. Further, the power unit 47 is stopped, the rotation of the turntable 44 is stopped, the connection of the gas pipe 65 is disconnected from the electrolyte temporary storage tank 40, and the valve driving unit 45 is removed from the piston type valve 41, and then transported The mold injection part 26 is removed from the turntable 44, and the fifth step is completed.

  As described above, the battery container 1 that was removed from the transport type liquid injection unit 26 by performing the first to fifth steps was referred to as Example 2. Moreover, the conveyance type liquid injection part 26 accommodates the battery container 1 which has not been injected, and is conveyed to a 1st process.

  In Example 3, the first process, the second process, and the fifth process of Example 1 are performed in the same manner. In the third process, each of the two-way valves 13, 14, shown in FIG. 17 is closed, the pressure reducing two-way valve 16 is opened, the high vacuum pressure regulator 9 set to a high vacuum pressure value and the vacuum pump 12 are operated, and the electrolyte in the electrolyte primary storage tank 4 containing the electrolyte is stored. The pressure is reduced to 1.0 kPa or less, which is the same as the pressure of the battery container 1, and the pressure in the battery container 1 and the electrolyte temporary storage tank 4 is brought into an equilibrium state. Next, the rotating disk 6 is rotated to apply a centrifugal force of about 300 G to the electrolytic solution, the valve drive unit 19 is operated to open the piston type valve 5, and the injection of the electrolytic solution only by the centrifugal force is started. An electrolyte amount of 5.8 g was injected.

  As shown in FIG. 9, the pressure applied to the battery container 1 in the fourth step is a predetermined pressure in 5 seconds from a pressure of 1.0 kPa or less to a pressure of 1000 kPa. Thus, the pressure in the battery container 1 and the electrolyte temporary storage tank 4 was controlled to be in an equilibrium state. Finally, the same fifth step as in Example 1 is performed.

  As described above, the first to fifth steps are carried out, the battery container 1 which has been injected and is impregnated with the electrolyte group 2 so that the electrolytic solution does not spill out is taken out, and the battery container 1 is taken as an example. It was set to 3.

In Example 4, it implements by the same method to the 2nd process of Example 1, and as FIG. 10 shows, in a 3rd process, a 3rd process is implemented after a 4th process. Specifically, the power unit 8 is driven, and the rotating disk 6 starts to rotate via a bearing unit 31 installed on the gantry 30. The rotation speed of the turntable 6 reaches 1000 rpm, and a predetermined centrifugal force is applied to the battery container 1 by about 300 G (gravitational acceleration is set to 1 G).
Further, in the fourth step to be performed first, after the atmospheric pressure release two-way valve 13 of the pressure adjusting unit 33 shown in FIG. 1 is closed (the two-way valves 16 and 17 are already closed), the air is increased by the pressure increasing valve 15. The pressure of the gas supplied from the generator 11 is increased approximately twice, the waveform control pressure two-way valve 14 is opened, and the inside of the electrolyte temporary storage tank 4 is linearly applied as shown in FIG. After the pressure is increased to 1000 kPa, the valve drive unit 19 in the third step is operated to open the piston type valve 5 and the centrifugal force acting on the battery container 1 and the battery container 1 After starting to inject the electrolyte of 5.8 g of the electrolyte in a pressurized state using the pressure difference between the reduced pressure and the pressurized state of the electrolyte temporary storage tank 4, The pressure of the electrolyte temporary storage tank 4 was brought into an equilibrium state. Next, in the fifth step, after the atmospheric pressure release two-way valve 13 is closed in a state where the centrifugal force is applied, the weak pressure reduction two-way valve 17 is opened, and the battery is set at 21.3 kPa set by the medium vacuum pressure regulator 10. The container 1 and the electrolyte storage tank 4 are depressurized for 10 seconds.

  Further, the weak pressure reduction two-way valve 17 is closed, the atmospheric pressure release two-way valve 13 is opened, the inside of the battery container 1 and the electrolyte temporary storage tank 4 are brought into an atmospheric pressure state, the valve driving unit 19 is operated, and the piston is operated. The mold valve 5 is closed. Further, the power unit 8 is stopped and the rotation of the rotating disk 6 is stopped, and the fifth step is completed. As described above, the first to fifth steps were performed, and the battery container 1 taken out was taken as Example 4.

As in Example 1, the first to fifth steps are performed, and the fourth and fifth steps are performed as shown in FIG. 11 without stopping the turntable 6 at the end of the fifth step. The battery container 1 taken out by repeating the above process was taken as Example 4.

  Specifically, after finishing the fifth step of Example 1 and injecting an electrolyte amount of 5.8 g into the battery container 1, it is centrifuged in the battery container 1 without stopping the turntable 6 shown in FIG. After the atmospheric pressure release two-way valve 13 in the pressure adjusting unit 33 is closed in a state where force is applied (the two-way valves 16 and 17 are already closed), the pressure of the gas supplied from the air generation unit 11 is changed. The pressure is increased approximately twice by the pressure-increasing valve 15 to increase the pressure, the waveform control pressure two-way valve 14 is opened, and the battery container 1 and the electrolyte temporary storage tank 4 in a pressurized state of 1000 kPa in the electrolyte temporary storage tank 4 The pressure inside is in an equilibrium state. Next, after maintaining the centrifugal force and the pressurized state for 60 seconds, the waveform control pressure two-way valve 14 is closed, the atmospheric pressure release two-way valve 13 is opened, and the pressure in the battery container 1 and the electrolyte temporary storage tank 4 is When the pressure reaches 101.3 kPa, which is an atmospheric pressure state, the fourth step is completed.

  In the next fifth step, the atmospheric pressure release two-way valve 13 is closed, then the weak pressure reduction two-way valve 17 is opened, and the battery container 1 and the electrolyte storage tank are set at 21.3 kPa set by the medium vacuum pressure regulator 10. The inside of 4 is decompressed for 10 seconds. Next, the weak pressure reducing two-way valve 17 is closed, the atmospheric pressure release two-way valve 13 is opened, the inside of the battery container 1 and the electrolyte temporary storage tank 4 are brought into the atmospheric pressure state, and the valve driving unit 19 is operated. The piston type valve 5 is closed. Further, the power unit 8 is stopped and the rotation of the rotating disk 6 is stopped, and the fifth step is completed. As described above, the first to fifth steps were performed, and the battery container 1 that was injected and taken out was designated as Example 5.

(Comparative Example 1)
In order to compare with the embodiment of the present invention, the battery container 101 in which the same electrolytic solution as the embodiment is not injected is incorporated into the apparatus having the configuration shown in FIG. The inside was depressurized for 60 seconds at a pressure of 14.7 kPa, and after closing the taper pin 105 between the battery container 101 and the electrolyte temporary storage tank 104, 5.8 g of electrolyte was converted to an electrolyte in an atmospheric pressure state. Supply to the temporary storage tank 104, apply rotation of 1000 rpm to the battery container 101 and the electrolyte temporary storage tank 104 in which the electrolytic solution is stored, and apply centrifugal force between the battery container 101 and the electrolyte temporary storage tank 104. The taper pin 105 was opened, and after 70 seconds had passed, the rotation was stopped, the battery taken out from the apparatus was set as Comparative Example 1, and the battery was left until the electrode group 2 in the battery container 101 was impregnated.

(Comparative Example 2)
In the desiccator container 202 shown in FIG. 13, the battery container 201 not injected with the same electrolytic solution as that of the example is housed. As the best mode of Comparative Example 2, the desiccator container 202 and the battery container 201 have a pressure of 8 kPa. The pressure was reduced for 60 seconds, and 5.8 g of the electrolyte was supplied to the battery container 201.

  Next, the desiccator container 202 and the battery container 201 are depressurized at a pressure of 3.5 KPa, and then gradually increased to 101.3 kPa of atmospheric pressure over a period of 45 seconds, and then at a pressure of 15 kPa for 25 seconds. Pressurization is performed, the inside of the desiccator container 202 and the battery container 201 is returned to atmospheric pressure, the battery container 201 taken out from the desiccator container 202 is set as Comparative Example 2, and the electrolytic solution is impregnated in the electrode group 2 in the battery container 201. I left it alone.

(Comparative Example 3)
A battery container 301 not injected with the same electrolytic solution as that of the example was installed in the apparatus configured as shown in FIG. 14, and the inside of the filling chamber 305 and the battery container 301 was depressurized at a pressure of 8 kPa for 60 seconds, The piston 303 was lowered, the electrolyte was extruded from the electrolyte temporary storage tank 304, and 5.8 g of electrolyte was injected from the discharge nozzle 302. Thereafter, the filling chamber 305 for 70 seconds is pressurized, the filling chamber 305 and the battery container 301 are returned to atmospheric pressure, the battery taken out from the apparatus is set as Comparative Example 3, and the electrolytic solution is applied to the electrode group 2 in the battery container 301. Leave until impregnated.

In order to compare the accuracy of the electrolyte solution injection times of Examples 1 to 5 and Comparative Examples 1 to 3 above, the amount of the loss electrolyte solution due to adhesion or volatilization to the apparatus during injection, the following evaluation results ( Table 1) shows.
The injection time, injection accuracy, and loss of electrolyte shown in Table 1 were measured as follows.
The liquid injection time was measured by impregnating the electrode group in the battery container. The accuracy of the injection is defined as the difference between the weight of the battery container into which the electrolyte has been injected and the weight of the battery container without the injection of the electrolyte plus 5.8 g of the weight of the electrolyte. The ratio with the amount of supplied electrolyte was shown. Each example was compared with the 30 battery containers implemented. In addition, the amount of loss of the electrolytic solution is the difference between the weight of the battery container into which the electrolytic solution has been injected and the weight obtained by adding 5.8 g of the weight of the electrolytic solution to the weight of the battery container without injecting the electrolytic solution. In each case, a comparison was made.

（表１）より明らかなように、実施例１〜５による方法は、比較例１〜３と比較して、短時間の注液時間ができ、注液精度が良好であり、高精度で電池容器内へ電解液を注液ができた。また、電解液の損失量においても少量であり、電解液の飛散、揮発の少ない注液方法と装置の実現ができた。比較例の注液精度、電解液の損失量の悪化要因は次のようになると考えられる。

As apparent from (Table 1), the methods according to Examples 1 to 5 enable a short time for injecting compared to Comparative Examples 1 to 3, the injection accuracy is good, and the battery is highly accurate. The electrolyte was poured into the container. In addition, the amount of loss of the electrolytic solution was small, and a liquid injection method and apparatus with little scattering and volatilization of the electrolytic solution could be realized. It is considered that the deterioration factors of the liquid injection accuracy and the loss amount of the electrolytic solution in the comparative example are as follows.

  In the method according to Comparative Example 1, the electrolyte solution is not impregnated in the electrode group in a short period of time, and it is necessary to impregnate in the atmospheric state for 3 minutes or more after injection, or to promote the impregnation by another impregnation method. As a result, the liquid loss increased and the injection accuracy deteriorated. Further, even in the method according to Comparative Example 2, the electrolyte solution is not impregnated in the electrode group in a short time, and impregnation is required in the atmospheric state for 10 minutes or more after the injection. Liquid accuracy deteriorated. Furthermore, even in the method according to Comparative Example 3, in a short time, 5.8 g of the electrolytic solution cannot be injected into the battery container and impregnated in the electrode group, and overflows from the battery container. In order to inject liquid so that it does not overflow, it is necessary to reduce the discharge speed of the electrolytic solution or to discharge intermittently in several batches, and pressurize or depressurize the atmosphere in the battery container. Therefore, it takes 10 minutes or more, and the loss of the liquid increases due to the volatilization of the electrolytic solution. Also, when the liquid is injected, the electrolytic solution adheres to the liquid injection path, and the liquid injection accuracy is thought to deteriorate.

  In Comparative Examples 1 to 3, the deterioration of the injection accuracy that occurs when the injection is performed in a short period of time results in variations in the amount of electrolyte in the battery container, and as a result, when the electrolyte is small, Insufficient electrolyte in the battery during charge / discharge leads to shortened battery life. Moreover, when there is much electrolyte solution, there exists a concern about the swelling of the battery by gas generation and the fall of safety | security. The present invention achieves stable battery life and stable safety by realizing highly accurate liquid injection in a short time of liquid injection.

ADVANTAGE OF THE INVENTION According to this invention, the liquid injection with a sufficient liquid injection precision is attained in the secondary battery battery container in spite of a short time. In addition, the electrolytic solution can be injected into the battery container in a short time due to the reduced pressure and pressurized state and the device structure in the battery container, and the electrolytic solution can be applied with high accuracy by the state in which the centrifugal force is applied and the device structure. It is possible to realize a liquid injection with a small loss. Furthermore, a large amount of electrolyte solution suitable for the electrode group can be accommodated in the electrode group in which as much as possible is wound in the battery container in order to increase the capacity of the secondary battery. It is possible to manufacture a secondary battery that provides effects such as excellent load characteristics with energy density and long shelf life.

The schematic diagram of the manufacturing apparatus of the secondary battery in Example 1 of this invention. The schematic diagram of the electrolyte temporary storage tank in another Example of this invention The schematic diagram of the conveyance type conveyance type liquid injection part in Example 2 of this invention The schematic diagram of the conveyance type conveyance type liquid injection part in the 1st process in Example 2 of this invention. The schematic diagram of the conveyance type conveyance type liquid injection part in the 2nd process in Example 2 of this invention. The schematic diagram of the conveyance type conveyance type liquid injection | pouring part in the 3rd, 4th, 5th process in Example 2 of this invention Phase diagram of pressure in battery container and electrolyte temporary storage tank in Examples 1 and 2 of the present invention Different state diagrams of pressure in battery container and electrolyte temporary storage tank in Examples 1 and 2 of the present invention State diagram of pressure in battery container and electrolyte temporary storage tank in Example 3 of the present invention State diagram of pressure in battery container and electrolyte temporary storage tank in Example 4 of the present invention State diagram of pressure in battery container and electrolyte temporary storage tank in Example 5 of the present invention Schematic schematic diagram showing a conventional liquid injection device Schematic schematic diagram showing a conventional liquid injection device Schematic schematic diagram showing a conventional liquid injection device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery container 2 Electrode group 3 Packing 4 Electrolyte temporary storage tank 5 Piston type valve 6 Turntable 7 Battery container fixing jig 8 Power part 9 Regulator for high vacuum pressure 10 Regulator for medium vacuum pressure 11 Air generating part 12 Vacuum pump 13 Atmospheric pressure Open two-way valve 14 Waveform control pressure two-way valve 15 Booster valve 16 Depressurization two-way valve 17 Weak decompression two-way valve 18 Supply pump 19 Valve drive unit 20 Supply nozzle 21 Electrolyte storage tank 22 Opening of battery container 23 Ball valve type Valve 24 Gas piping 25 Fluid piping 27 Valve driving section 29 Gas piping 30 Mounting base 31 Bearing section 32 Electrolyte supply section 33 Pressure adjusting section 35 Depressurizing adjusting section 41 Piston type valve 42 Packing 43 Battery container fixing jig 45 Valve driving section 46 Bearing section 47 Power section 48 Mount 50 Air release two-way valve 51 Pressure reduction two-way valve 52 Takashin Regulator for pressure 53 Vacuum pump 54 Electrolyte storage tank 55 Supply pump 56 Supply nozzle 57 Waveform control pressure two-way valve 58 Booster valve 59 Air generator 60 Atmospheric release two-way valve 61 Weak pressure reduction two-way valve 62 Medium vacuum pressure regulator 63 Vacuum pump 64 Fluid piping 65 Gas piping

Claims (6)

  Between the positive electrode current collector coated with a positive electrode mixture paint containing at least a positive electrode active material and a negative electrode current collector coated with a negative electrode mixture paint containing at least a negative electrode active material between them. A method of manufacturing a secondary battery in which an electrode group wound in a spiral shape with a separator interposed is inserted into a battery container, an electrolytic solution is injected into the battery container and sealed with a sealing body, and the electrode group is The opening of the stored battery container and the electrolyte temporary storage tank are connected via an elastic body. After the pressure inside the battery container is reduced through the temporary electrolyte storage tank, the valve for opening and closing the temporary electrolyte storage tank is closed. A first step of maintaining the inside of the battery container in a reduced pressure state, a second step of supplying a predetermined amount of the electrolyte into the electrolyte temporary storage tank, and a state in which centrifugal force is then applied to the electrolyte And the third step of opening the valve and injecting the electrolyte into the battery container, The battery container and the electrolyte container temporary storage tank are in a balanced state through the fourth step, and the battery container is further reduced in pressure through the electrolyte solution temporary storage tank. A method for producing a secondary battery, comprising injecting an electrolyte solution into the battery.   In the third step, the inside of the electrolyte temporary storage tank is depressurized, and the valve is opened in a state where centrifugal force is applied to the electrolyte, and liquid is injected into the battery container containing the electrode group. 2. A method for producing a secondary battery according to 1.   In the third step, the electrolyte is temporarily put into a pressurized state while a centrifugal force is applied to the electrolyte, and the valve is opened to inject the solution into the battery container containing the electrode group. The manufacturing method of the secondary battery as described.   In the third or fourth step, the pressure control in the electrolyte temporary storage tank is increased along a linear line that depends on time or a waveform that follows a function of a curve, and in the battery container housing the electrode group and the electrolyte 4. The method of manufacturing a secondary battery according to claim 1, wherein the pressure of the temporary storage tank is brought into an equilibrium state.   5. The method for producing a secondary battery according to claim 1, wherein the electrolytic solution is injected into a battery container containing the electrode group by repeating the fourth step and the fifth step a plurality of times. .   Temporary storage of an electrolytic solution in which a battery container containing an electrode group formed by winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween and an opening of the battery container are connected via an elastic body A valve that opens and closes the electrolyte temporary storage tank, a pressure adjusting unit connected to the electrolyte temporary storage tank that sucks and discharges gas in the battery container and the temporary electrolyte storage tank, and the temporary storage tank A rotating disk for applying centrifugal force to the electrolyte supplied to the electrolyte temporary storage tank by fixing and rotating, a pump for supplying the electrolyte into the electrolyte temporary storage tank, and the electrolyte temporary storage tank A pressure reducing pump, a switching valve for switching the inside of the electrolyte temporary storage tank to a pressure reducing, pressurizing, and atmospheric pressure state, a drive unit for opening and closing a valve for opening and closing the electrolyte temporary storage tank, and the rotating disk It is composed of a drive unit that rotates. Battery manufacturing equipment.

Images