JP2007173063A - Method of manufacturing flat battery and its manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-accuracy and high-efficiency manufacturing method for rapidly injecting a minute quantity of electrolyte even for an ultraminiature battery small in electric capacity of a flat battery; and to provide a manufacturing device. <P>SOLUTION: An electrolyte pressure-fed from an electrolyte tank 20 is injected into an upper case 1 having an injection valve 8 in a boundary between an electrolyte syringe 7 and an injection nozzle 16 and composed by stacking and housing a negative electrode body 4 and a separator 5 of an electrode body housed in a decompression chamber 9 reduced in pressure from the injection nozzle 16 by opening/closing the valve, and thus the electrolyte without being exposed to the atmosphere and decompressed air for a long time is accurately and efficiently injected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flat battery manufacturing method and a manufacturing apparatus thereof suitable for quickly injecting an electrolyte into a flat battery case while impregnating a negative electrode body and a separator.

  In recent years, coin batteries have been typified by flat batteries, tending to withstand harsh environments as the main power source for vehicles and watches, and the demand for long-term reliable coin batteries with a 10-year warranty has increased. ing. Manufacturing processes for coin-type batteries require manufacturing that ensures stable quality, and in order to ensure long-term storage, there is little variation in the amount of electrolyte injected, which is a major factor affecting the storage characteristics of batteries. Strict injection volume accuracy is required.

  Manufactured by injecting an electrolyte solution into an upper case containing an electrode body composed of a laminate structure of a negative electrode body, a positive electrode body and a separator, and then covering the upper case with the lower case and caulking and sealing the opening of the lower case. In the coin battery, when an electrolyte is injected into the upper case, it takes time to impregnate the electrode body, which is a high-density active material, with the electrolyte. Furthermore, if the electrolyte solution is impregnated for a long time to be impregnated, the electrolyte solution evaporates and causes a variation in the electrolyte solution amount.

  As a conventional method of injecting an electrolytic solution, as shown in FIG. 5, a predetermined amount of electrolytic solution is supplied to the filling cylinder 102 by filling the electrolytic solution with a fixed nozzle 101. The piston 103 closes the upper end of the filling cylinder 102, exhausts the air in the filling cylinder 102 from the exhaust port 104 at the upper end of the piston 103, and puts the inside of the decompression chamber 105 and the inside of the case 106 into a decompressed state. The electrolytic solution supplied to the filling cylinder 102 is placed in the case 106 in the decompression chamber 105 in a decompressed state after the electrolytic solution is pushed out by the piston 103 inserted in the filling cylinder 102 and passes through the liquid injection pipe 107. A method of injecting a fixed amount of electrolyte has been proposed (see, for example, Patent Document 1).

  Further, as shown in FIG. 6, the case 152 is stored in the filling chamber 151, the piston main body 154 stored in the temporary storage chamber 153 is removed, and a necessary amount of electrolyte is supplied into the filling cylinder 153. The piston main body 154 is inserted into the filling cylinder 153. Next, after reducing the pressure in the filling chamber 151, the piston body 154 is pushed down to raise the electrolyte level, and the electrolyte extruded from the filling cylinder 153 passes through the injection pipe 155 and is injected into the case 152. Then, a method has been proposed in which the filling chamber 151 is pressurized and injected (for example, see Patent Document 2).

Further, as shown in FIG. 7, the case 202 disposed on the disc 201 and the holder 203 are connected, and after the case 202 is depressurized, a necessary amount of electrolyte is supplied to the filling cylinder 204. Next, the disc 201 is rotated and a centrifugal force is applied to the case 202 and the filling cylinder 204. Thereafter, the taper pin 205 is opened, and in addition to the pressure difference between the negative pressure in the case 202 and the atmospheric pressure in the filling cylinder 204, centrifugal A method of injecting an electrolytic solution in consideration of force has been proposed (see, for example, Patent Document 3).
JP 2004-055238 A JP-A-9-102443 JP-A-8-106896

However, in the above-described prior art of the patent document, since the electrolyte solution is exposed to atmospheric pressure or a reduced pressure state for several tens of seconds or more in order to impregnate the electrode body, the electrolyte solution is not evaporated. Variations in the injection amount of the electrolyte that occur due to the urge are generated. Furthermore, there is a problem that the amount of the electrolyte solution injected due to the electrolyte solution adhering to the surface of the filling cylinder or the electrolyte solution path is insufficient, and further, the components of the electrolyte solution are varied.

  The present invention has been made in view of the above-described conventional problems, and by pouring the electrolyte solution while pressurizing the electrolyte solution with a gas whose pressure is controlled in an upper case in which the negative electrode body and the separator are stacked and accommodated, The dispersion of the injection volume is suppressed by suppressing the adhesion of the electrolyte to the surface of the path as much as possible, and the electrolyte is poured into the upper case while the electrolyte is immediately impregnated in the gap between the negative electrode body and the separator. Do not leave for a long time at atmospheric pressure or under reduced pressure to impregnate the electrode body before and / or the electrode body. An object of the present invention is to provide a method of manufacturing a flat battery and an apparatus for manufacturing the same that efficiently impregnates the electrolyte solution and efficiently impregnates the electrolyte.

  In order to achieve the above object, the flat battery manufacturing method of the present invention includes a negative electrode body made of a material capable of holding lithium as an active material and a positive electrode body made of a positive electrode active material with a separator interposed therebetween. The laminated electrode body and electrolyte solution are stored in a container-like upper case having an insulating gasket at the periphery of the opening, and the container-like lower case opening that covers the upper case is sealed. A method for producing a flat battery for sealing, in which an upper case containing a stack of a negative electrode body and a separator of an electrode body is placed in a decompression chamber, and after the decompression chamber is decompressed, the electrolyte syringe is filled. The electrolytic solution is injected while being pressurized with a gas whose pressure is controlled.

  According to the present invention, the upper case in which the negative electrode body and the separator of the electrode body are stacked and accommodated is placed in the decompression chamber, the inside of the decompression chamber is decompressed, and the electrolyte filled in the electrolyte syringe is controlled to control the pressurizing force. By injecting while pressurizing with the generated gas, the electrolyte is prevented from adhering to the surface of the electrolyte path as much as possible, and variations in the injection volume are suppressed. Despite impregnating the electrolyte and suppressing variations in the injection volume of the electrolyte, variations in the injection volume of the electrolyte due to evaporation of the electrolyte and changes in components are suppressed, improving the injection accuracy and improving efficiency. It is possible to impregnate the electrolytic solution.

  In the first invention of the present invention, a negative electrode body comprising a material capable of holding lithium as an active material and a positive electrode body comprising a positive electrode active material and an electrode body having a laminated structure in which a separator is interposed therebetween and electrolysis This is a method for manufacturing a flat battery in which liquid is stored in a container-like upper case having an insulating gasket at the periphery of the opening, and the opening of the container-like lower case covered by the upper case is sealed and sealed. Then, the upper case containing the negative electrode body and the separator stacked and housed in the electrode body is placed in a decompression chamber, the pressure inside the decompression chamber is reduced, and then the electrolyte solution filled in the electrolyte syringe is gas whose pressure is controlled. By injecting while pressurizing with an electrolyte, it is possible to suppress the electrolyte from adhering to the surface of the electrolyte path as much as possible to suppress variations in the injection amount of the electrolyte, and to promptly perform electrolysis in the gap between the negative electrode body and the separator. Contains liquid In addition, the electrolyte solution is not exposed to atmospheric pressure for several tens of seconds before being injected or impregnated, and is not exposed to a reduced pressure for a long time. It is possible to suppress changes in the components of the liquid and improve the accuracy of liquid injection.

In the second invention of the present invention, it is possible to touch the air by injecting into the upper case while pressurizing the electrolyte solution always filling the electrolyte syringe with an inert gas whose pressure is controlled. Therefore, it is possible to suppress changes in the components of the electrolytic solution, and to control the rate of injection with a controlled pressure.

  In the third aspect of the present invention, an upper case containing a negative electrode body and a separator laminated and accommodated is placed in a vacuum chamber, and an electrolyte solution filled in an electrolyte syringe under atmospheric pressure is used. By injecting while pressurizing with a gas whose pressure is controlled, impregnation with the electrolyte is promoted, and impregnation in a short time becomes possible. Furthermore, it is possible to inject liquid while pressurizing with a gas whose pressure is controlled without depressurizing the inside of the decompression chamber.

  In a fourth aspect of the present invention, a gas pressurization having an upper case having an insulating gasket that is housed by laminating a negative electrode body and a separator and a decompression chamber that houses the upper case, and connected to an electrolyte tank An electrolyte syringe connected to the electrolyte tank, a liquid injection valve that opens and closes the electrolyte syringe, a valve drive unit that operates the liquid injection valve, a liquid injection nozzle connected to the liquid injection syringe, With the pressure adjustment unit connected to the decompression chamber, it is possible to suppress the electrolyte from adhering to the surface of the electrolyte syringe or the injection valve that is the path of the electrolyte as much as possible, and to vary the injection amount of the electrolyte. It is possible to quickly impregnate the negative electrode body, the separator and the gap between them with an electrolyte. In addition, the electrolytic solution is not exposed to atmospheric pressure for several tens of seconds before injection or during impregnation, and is not exposed to a reduced pressure for a long time. Variations in the amount of liquid can be suppressed, and the accuracy of liquid injection can be improved.

  In the fifth aspect of the present invention, the electrolyte tank is configured to be pressurized with an inert gas whose pressurization is controlled by the gas pressurizing unit, thereby suppressing changes in the components of the electrolyte and reducing the pressure. Since it is possible to suppress the applied pressure corresponding to the decompression force of the chamber, efficient liquid injection is possible.

  In the sixth aspect of the present invention, since the valve driving portion is constituted by the rotation generating portion and the cam mechanism, the liquid injection valve of the electrolyte syringe can be operated with high accuracy, and the liquid injection can be performed with high accuracy. Capable of handling extremely small volumes of liquid.

  In the seventh aspect of the present invention, since the electrolyte syringe and the injection nozzle are configured to be separable, the adhesion of the electrolyte solution can be suppressed, and the injection nozzle is blocked due to the solidification of the electrolyte solution. Easy cleaning and improved maintainability.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. An embodiment shown below shows a manufacturing apparatus for explaining the present invention in detail, and the present invention specifies the structure and manufacturing apparatus of a flat battery as follows. is not. For example, FIG. 2 is a schematic view of a flat battery manufacturing apparatus showing a state when the decompression chamber of the present invention is connected. As shown in FIG. 2, after holding the upper case 1 containing a negative electrode body 4 and a separator 5, which will be described in detail later, on a gantry 10, a decompression chamber 9 provided in an electrolyte syringe 7 is connected. The gantry 10 is provided with an O-ring groove 11 and an O-ring 32 is fitted in the O-ring groove 11 to ensure airtightness in the decompression chamber 9.

  Next, the decompression chamber 9 is connected to a decompression generator 15 comprising a decompression regulator 12, a decompression pressure gauge 13, and a decompression on / off valve 14, and the degree of vacuum of a vacuum pump (not shown) is adjusted, The pressure is adjusted. At this time, the higher the degree of vacuum in the decompression chamber 9 is, the more preferable, but if the degree of vacuum is too high, the electrolyte solution boils and is an important factor that determines the amount of liquid to be injected in the present invention. Monitoring is performed with a total of 13, and if the degree of vacuum is not within the allowable upper and lower limits, the manufacturing apparatus of the present invention is stopped. It is also possible to inject liquid without reducing the pressure in the vacuum chamber 9.

  The electrolyte syringe 7 that stores the electrolyte is equipped with an injection valve 8 inside, and is connected to the valve drive unit 29 via a cam follower 26 attached to the tip of the injection valve 8. The valve drive unit 29 is composed of a disk-shaped plate cam 27 and a servo motor 28, and the servo motor 28 rotates the plate cam 27 to transmit the vertical movement to the liquid injection valve 8 to open and close the liquid injection valve 8. The electrolyte solution is injected into the upper case 1. It is possible to control the amount of electrolyte by changing the rotation speed of the plate cam 27. When the rotation speed of the plate cam 27 is increased, the amount of electrolyte decreases. Here, as an embodiment of the present invention, the rotational movement of the plate cam 27 is used for the valve drive unit 29. However, the present invention is not limited to this, and a vertical movement by an air cylinder or a mechanism combining a cam, a ball screw, and a servo motor. The vertical movement of the liquid injection valve 8 can also be transmitted by a mechanism or the like.

  In addition, a spring 24 is attached to the liquid injection valve 8, assisting the vertical movement of the liquid injection valve 8, and an O-ring fitted to the electrolyte syringe 7 to ensure airtightness with the electrolyte chamber 30. Isolated at 25.

  Further, the injection nozzle 16 is connected to the electrolyte syringe 7 by closing the nut 17, and can be easily separated from the electrolyte syringe 7 by loosening the nut 17, and the injection nozzle 16 corresponding to the amount of electrolyte By selecting the length of the protrusion at the tip of the liquid injection nozzle 16, it is possible to perform liquid injection with higher accuracy. Furthermore, since the injection nozzle can be easily clogged due to the solidification of the electrolytic solution, the structure is rich in maintainability. A material such as polypropylene or ethylene tetrafluoride resin is suitable for the material of the contact surface with the liquid injection valve 8.

  An electrolytic solution supply port 23 of the electrolytic solution chamber 30 in the electrolytic solution syringe 7 is connected to the electrolytic solution supply unit 23 so that the electrolytic solution chamber 30 is always filled with the electrolytic solution. It consists of a pressure feed pipe 19, an electrolyte solution tank 20, an inert gas pressure gauge 21, and an inert gas pressure regulator 22. The electrolyte supply unit 23 connected to an inert gas tank (not shown) adjusts the pressure of the inert gas by the inert gas pressure regulator 22 so that the electrolyte tank 20 is pressurized, and the pressure is increased. The charged electrolyte fills the electrolyte chamber 30. Here, since it is an important factor for determining the amount of liquid to be injected of the present invention in the same manner as the decompression in the decompression chamber 9, the production apparatus of the present invention must be within the allowable upper and lower limits by the inert gas pressure gauge 21. To stop. The inert gas may be carbon dioxide, nitrogen, argon, or the like. In the present invention, nitrogen gas is used to apply pressure to the electrolyte tank 20 to obtain a pressurized electrolyte.

  Furthermore, it is possible to control the discharge speed of the electrolytic solution by changing the applied pressure of the electrolytic solution. When the applied pressure of the electrolytic solution is increased, the discharged speed of the electrolytic solution is also increased. In addition, since the electrolytic solution chamber 30 is filled with the pressurized electrolytic solution, it is possible to prevent bubbles from entering the electrolytic solution chamber 30, and bubbles in the electrolytic solution are provided in the middle of the electrolytic solution feeding pipe 19. It is also possible to provide a deaeration mechanism (not shown) for removing the water.

  The inside of the decompression chamber 9 is decompressed by the decompression generating section 15, the valve driving section 29 is operated to open and close the liquid injection valve 8, and the upper case is caused by the pressure difference between the applied pressure of the electrolyte and the decompression in the decompression chamber 9. An electrolytic solution is poured onto one separator 5. In addition, one, several, or several tens of these manufacturing apparatuses are arranged as a line, and each manufacturing apparatus can inject electrolyte into the upper case 1 in parallel to increase the processing capacity. By using it as a jig that circulates the gantry 10, it becomes possible to adopt a line configuration with higher productivity.

  As shown in FIG. 4, the injected upper case 1 is formed by laminating the positive electrode body 3 on the separator 5 and covering the lower case 6. The side surface of the lower case 6 is reduced in diameter and the opening of the lower case 6. Is folded inward and sealed, and the insulating gasket 31 is compressed to form a flat battery with high airtightness.

  Here, the flat battery includes a coin-type primary battery, a coin-type secondary battery, and the like. Here, a coin-type lithium ion secondary battery (hereinafter, coin-type secondary battery), which is one of the flat batteries, is used. Next, FIG. 4 which is a cross-sectional view showing the overall configuration of the secondary battery will be described. The coin-type secondary battery 33 includes a pellet-shaped positive electrode body 3 constituting the electrode body 2, a pellet-shaped negative electrode body 4, and a separator 5 disposed between the positive electrode body 3 and the negative electrode body 4. An upper case 1 that houses an electrolyte (not shown) that moves lithium ions between the body 3 and the negative electrode body 4 and the electrode body 2 and an upper case that seals a space in which the electrode body 2 of the upper case 1 is housed. 1 comprises an insulating gasket 31 at the peripheral edge of the opening 1 and a lower case 6 that covers and seals the upper case 1. Further, a seal film (not shown) is formed at predetermined positions on the outer peripheral surface of the opening of the upper case 1, the inner peripheral surface of the insulating gasket 31, and the inner peripheral surface of the opening of the lower case 6. And exhibit higher airtightness.

  Here, the positive electrode body 3 uses a lithium manganate compound, but is not limited thereto. For example, any one or more of a lithium composite oxide, a metal sulfide, a metal oxide, a metal selenium compound and the like are mixed. It can also be used.

  Further, the negative electrode body 4 is formed by punching plate-like metallic lithium or a lithium alloy serving as a negative electrode active material into a pellet shape. The negative electrode body 4 is stored in the coin-type secondary battery 33 in a state in which pellet-shaped metallic lithium and a metal or compound that can be combined with lithium are bonded together, and is left to be a lithium alloy. Used as negative electrode active material.

  Next, the separator 5 interrupts | blocks between the positive electrode body 3 and the negative electrode body 4, and allows the lithium ion in electrolyte solution to pass through, preventing the short circuit by the contact of both electrode materials. The separator 5 is a non-woven fabric formed of a fiber resin, and has a porosity of 10% to 50% and a thickness of 40 μm to 200 μm. Here, although polyphenylene sulfite is used, it is not limited to this, Polyethylene terephthalate, a polyimide, polyamide, etc. are raised, It is also possible to use any 1 or more types.

  Examples of the electrolyte include EMC, pentag lime, and tetraglyme, and any one or more of these are used.

  The lower case 6 is a container made of a conductive metal, and serves as an external positive electrode of the coin-type secondary battery 33 by being in contact with the positive electrode body 3. Specifically, a metal container made of stainless steel or the like is used for the lower case 6, but the present invention is not limited to this. For example, the lower case 6 is made of metal in a state where a plurality of metals such as stainless steel, aluminum, and nickel are laminated. It is also possible to use other containers.

  The upper case 1 is a container made of a conductive metal that houses the electrode body 2, and becomes an external negative electrode of the coin-type secondary battery 33 by being in contact with the negative electrode body 4. The upper case 1 is formed using a clad material or the like in which aluminum and stainless steel are bonded so that the first metal layer is aluminum. Pellets of metallic lithium are attached to the bottom surface where the negative electrode body 4 is accommodated, and a lithium alloy is formed after the secondary battery is assembled.

  The insulating gasket 31 is formed in an annular shape, and is attached so as to be fitted into a gap generated between the lower case 6 and the upper case 1 when the lower case 6 and the upper case 1 are sealed. The gap is sealed. This insulating gasket 31 uses polyphenylene sulfite resin, but is not limited thereto, polyether ketone resin, polyether ether ketone resin, polyethylene terephthalate resin, polyarylate resin, etc. can be used, Any one kind or a plurality of kinds may be mixed and used.

  A sealing agent (not shown) is applied as a sealing film to the inner peripheral side surface of the lower case 6 and the inner peripheral side surface of the insulating gasket 31, and between the lower case 6 and the upper case 1 and the insulating gasket 31. The tightness of the internal space of the coin-type secondary battery 33 is further improved by entering the generated minute gap. Specifically, a fluorine-based resin is used for the sealant, and the above-described fluorine-based resin is dissolved in the solvent for preparing the sealant. Specifically, cyclohexane or the like is used.

  Next, a method for manufacturing a flat battery according to an embodiment of the present invention will be described in detail with reference to the drawings.

The schematic diagram of the flat battery manufacturing apparatus which shows the state before connecting the decompression chamber in Example 1 of this invention is shown in FIG. The inert gas pressure regulator 22 in the electrolyte supply unit 23 is operated to adjust the pressure of the inert gas sent from an inert gas tank (not shown) to 90 kPa, and the electrolyte tank 20 has a pressure of 90 kPa. The electrolyte solution is in the state of a charged electrolyte solution, and the electrolyte solution is pumped to the electrolyte solution supply port 18 of the electrolyte solution syringe 7 connected to the electrolyte solution tank 20 via the electrolyte solution feeding tube 19, and the injection valve 8 is closed. The electrolytic solution chamber 30 is filled with an electrolytic solution having a pressure of 90 kPa.

  Further, the upper case 1 in which the electrolyte containing the negative electrode body 4 and the separator 5 is not injected is held at a fixed position on the gantry 10 where the decompression chamber 9 is not mounted. The holding method may be a chuck, vacuum suction, or magnetic holding method. In the present invention, a circular recess into which the upper case 1 can be fitted is provided and fixed to the gantry 10 that can simplify the structure.

  The decompression chamber 9 is attached to the gantry 10 in the direction of the arrow shown in FIG. 2, and then the decompression on / off valve 14 in the decompression generating unit 15 is opened and the decompression regulator 12 is operated to reduce the pressure in the decompression chamber 9. The pressure is reduced to 10 kPa, which is about 1/10 of the atmospheric pressure set at 12.

FIG. 3 is a schematic view of a flat battery manufacturing apparatus showing an electrolyte injection state in Example 1 of the present invention. The servo motor 28 in the valve drive unit 29 is driven to rotate the plate cam 27, and the liquid injection valve 8 is lifted upward by the force of the spring 24 via the cam follower 26 at the tip of the liquid injection valve 8. The liquid injection nozzle 16 having an inner diameter of 1 mm in the liquid injection nozzle 16 in this embodiment is opened as shown in FIG. 3, so that the electrolyte is applied with the pressure of the electrolyte and the reduced pressure in the vacuum chamber 9. The liquid injection into the upper case is started by the differential pressure, and then the liquid injection valve 8 is closed by the rotation of the plate cam 27 and the liquid injection is finished. Further, the liquid injection amount of the present invention is 62 mg, and the liquid injection valve 8 has an opening / closing time of only about 0.1 to 0.2 seconds, and the servo motor 28 stops after one rotation.
After injection, the vacuum is maintained for 2 seconds, and the separator 5 is impregnated with the electrolyte, and then the vacuum regulator 12 in the vacuum generator 15 is operated to increase the pressure in the vacuum chamber 9 to 101.3 kPa, which is atmospheric pressure, for 2 seconds. Returned with time. In the case of a lithium battery, dry air may be used as the supply air when opening to the atmosphere. The upper case 1 taken out by opening the decompression chamber 9 was taken as Example 1.

As in Example 1, after the upper case 1 not filled with the electrolyte containing the negative electrode body 4 and the separator 5 was held at a fixed position on the gantry 10 and the decompression chamber 9 was attached to the gantry 10 The liquid injection was started while the pressure in the vacuum chamber 9 was kept at atmospheric pressure without reducing the pressure. After the injection, the upper case 1 was left as an atmospheric pressure for 6 seconds, and the decompression chamber 9 was opened and taken out.

(Comparative Example 1)
In order to compare with the embodiment of the present invention, an upper case 106 containing a negative electrode body and a separator not filled with the same electrolytic solution as the embodiment into an apparatus configured as shown in FIG. After supplying 62 mg of the electrolytic solution to the filling cylinder 102, the pressure in the decompression chamber 105 is reduced to a pressure of 10 kPa, the piston 103 is pushed down, and the electrolytic solution is injected into the upper case 106 from the liquid injection tube 107 for 2 seconds. After the depressurization, the decompression chamber 105 is returned to a pressure of 101.3 kPa, which is atmospheric pressure. Next, the decompression chamber 105 was opened, and the upper case 106 taken out was used as Comparative Example 1.

  The results of the following evaluation are shown in (Table 1) in order to compare the weight of the loss electrolyte by dispersion or volatilization due to volatilization or volatilization during the injection of the same electrolyte in the above examples and comparative examples. Show.

  The variation in the weight of the electrolytic solution shown in Table 1 was obtained by adding 62 mg of the weight of the electrolytic solution to the weight of the upper case where the electrolytic solution had been injected and the weight of the upper case where the electrolytic solution had not been poured. The difference from the weight was taken as the weight of the injected electrolyte, and the maximum value of the 20 upper cases carried out was compared with the difference between the minimum values.

  In addition, the weight loss of the electrolytic solution is the difference between the weight of the upper case where the electrolytic solution has been injected and the weight of the upper case where the electrolytic solution has not been added plus 62 mg of the weight of the electrolytic solution. The weight of the liquid electrolyte was compared, and the difference between the minimum weight of the electrolyte and the weight of the supplied standard electrolyte 62 mg was compared.

（表１）より明らかなように実施例１，２による方法は、比較例１とを比較して注液時における電解液の重量のバラツキも少なく精度が良好であり、上ケースに高精度な電解液の注液ができた。また、電解液の基準重量６２ｍｇに対しても差が小さく、電解液の損失重量が少ないことで、電解液の飛散、電解液の蒸発の少ない製造方法と製造装置と言うことができ、電解液の蒸発を抑制できたことで電解液の成分のバラツキを抑えることのできる方法である。さらに、実施例１と実施例２を比較すると減圧チャンバー内を減圧することで電解液の損失に対して効果的であった。また、に比較例１の方法では、電解液の重量が小さくなればなるほど構造が小さくなり、さらなる小型化に対応した方法としては断念せざるを得ない。

As apparent from (Table 1), the methods according to Examples 1 and 2 have less accuracy in the weight of the electrolyte during injection compared to Comparative Example 1, and the accuracy is good, and the upper case is highly accurate. The electrolyte was injected. Further, the difference is small with respect to the standard weight of the electrolytic solution of 62 mg, and the loss weight of the electrolytic solution is small, so that it can be said that the manufacturing method and the manufacturing device cause little scattering of the electrolytic solution and evaporation of the electrolytic solution. This is a method capable of suppressing the variation in the components of the electrolytic solution by suppressing the evaporation of the electrolyte. Further, comparing Example 1 and Example 2, it was effective against the loss of the electrolyte solution by reducing the pressure in the vacuum chamber. In addition, in the method of Comparative Example 1, the structure becomes smaller as the weight of the electrolytic solution becomes smaller, and it must be abandoned as a method corresponding to further miniaturization.

It is considered that the variation in the injection accuracy of Comparative Example 1 and the deterioration factor of the loss amount of the electrolytic solution are as follows. In the method according to Comparative Example 1, it is considered that the electrolytic solution adhered to the surface of the filling cylinder, the piston, and the path of the electrolytic solution, resulting in variations in the weight of the injected electrolytic solution. The evaporation of the liquid is also considered to be the cause of the increased weight loss of the electrolyte. In addition, in the method according to Comparative Example 1, the electrolyte solution is likely to overflow on the positive electrode body to the extent that it can be visually confirmed, and when the lower case is covered and sealed, the electrolyte solution leaks out. It was confirmed visually. This causes a wide variety of problems such as equipment contamination due to overflowing electrolyte and associated equipment operation trouble, secondary battery surface contamination due to liquid spillage, and quality problems such as deterioration of battery characteristics due to lack of liquid. It has also been confirmed.

  As described above, in the comparative example, the deterioration of the injection accuracy that occurs when the injection is performed in a short period of time results in variations in the weight of the electrolytic solution. At times, the electrolyte in the secondary battery is insufficient, leading to a 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.

  According to the present invention, it is possible to inject liquid with high accuracy in injecting a battery in spite of a short time. In addition, the manufacturing method and the manufacturing apparatus of the present invention can eliminate various troubles related to spillage of the electrolyte by injecting using an appropriate balance between the pressure applied to the electrolyte and the pressure reduction of the upper case, It becomes possible to inject a minute amount of electrolytic solution, which has been difficult with the prior art, and is useful as a method for injecting the electrolytic solution of a high-performance flat micro battery. Furthermore, since a large amount of electrolyte corresponding to the electrode body can be accommodated in an electrode body that accommodates as much as possible in the battery in order to increase the capacity, the load characteristics can be increased with high energy density. It is possible to produce a battery that is excellent and has effects such as a long shelf life.

The schematic diagram of the flat battery manufacturing apparatus which shows the state before connecting the decompression chamber in Example 1 of this invention. The schematic diagram of the flat battery manufacturing apparatus which shows the state at the time of connecting the decompression chamber of this invention The schematic diagram of the manufacturing apparatus of the flat battery which shows the injection state of the electrolyte solution in Example 1 of this invention Sectional drawing of the coin-type secondary battery in one Embodiment of this invention Embodiment of a prior art liquid injection device Embodiment of another conventional liquid injection device Embodiment of another conventional liquid injection device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper case 2 Electrode body 3 Positive electrode body 4 Negative electrode body 5 Separator 6 Lower case 7 Electrolyte syringe 8 Injection valve 9 Depressurization chamber 10 Mounting frame 11 O-ring groove part 12 Decompression regulator 13 Decompression pressure gauge 14 Decompression opening / closing valve 15 Decompression generation part 16 Injection nozzle 17 Nut 18 Electrolyte supply port 19 Electrolyte pressure feed pipe 20 Electrolyte tank 21 Inert gas pressure gauge 22 Inert gas pressure regulator 23 Electrolyte supply part 24 Spring 25 O-ring 26 Cam follower 27 Plate cam 28 Servo motor 29 Valve drive unit 30 Electrolyte chamber 31 Insulating gasket 32 O-ring 33 Coin type secondary battery (flat battery)

Claims (7)

  Insulating gaskets having a negative electrode body comprising a material capable of holding lithium as an active material and a positive electrode body comprising a positive electrode active material having a laminated structure in which a separator is interposed therebetween and an electrolyte solution at the periphery of the opening A flat battery manufacturing method for sealing and sealing an opening of a container-like lower case covered by the upper case, the negative electrode body of the electrode body and The upper case with the separators stacked and installed is placed in a vacuum chamber, the pressure inside the vacuum chamber is reduced, and the electrolyte filled in the electrolyte syringe is injected while being pressurized with a gas whose pressure is controlled. A method for manufacturing a flat battery.   2. The flat shape according to claim 1, wherein the electrolyte solution filled in the electrolyte solution syringe so as not to contain air is always injected into the upper case while being pressurized with an inert gas whose pressure is controlled. A manufacturing method of a battery.   An upper case in which the negative electrode body and separator of the electrode body are stacked and housed is installed in a vacuum chamber, and the electrolyte filled in the electrolyte syringe is pressurized with a gas whose pressure is controlled under atmospheric pressure. The method for producing a flat battery according to claim 1, wherein the liquid is injected.   An upper case provided with an insulating gasket in which a negative electrode body made of a material capable of holding lithium as an active material and a separator are stacked and stored, and a decompression chamber for storing the upper case, and a gas supply connected to an electrolyte tank A pressure part, an electrolyte syringe connected to the electrolyte tank, a liquid injection valve that opens and closes the electrolyte syringe, a valve drive unit that operates the liquid injection valve, a liquid injection nozzle connected to the liquid injection syringe, A flat battery manufacturing apparatus comprising a pressure adjusting unit connected to the decompression chamber.   The apparatus for manufacturing a flat battery according to claim 4, wherein the electrolyte tank is configured to be pressurized with an inert gas whose pressure is controlled by a gas pressurizing unit.   The flat battery manufacturing apparatus according to claim 4, wherein the valve driving unit includes a rotation generating unit and a cam mechanism. The flat battery manufacturing apparatus according to claim 4, wherein the electrolytic solution syringe and the injection nozzle are configured to be separable.

Images