JP2014022336A - Liquid injection device and liquid injection method for nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid injection device and liquid injection method for a nonaqueous secondary battery, facilitating pressure control at the inside of a battery can.SOLUTION: When pressure is reduced, a pressure adjustment mechanism including a pressure adjustment container 64 is used, the pressure adjustment container suppressing pressure fluctuations at the inside of a battery can 102 and in a vacuum line 67 that is a path for reducing pressure.

Description

  The present invention relates to a liquid injection device and a liquid injection method for a non-aqueous secondary battery. In the specification of the present application, the injection refers to injecting an electrolytic solution into a battery can of a non-aqueous secondary battery.

  In order to smoothly inject liquid, a technique is known in which two holes are provided in a battery can, liquid is injected from one hole, and air is exhausted from the other hole to depressurize the inside of the battery can. .

  In Patent Document 1, in order to smoothly perform liquid injection, a plurality of liquid injection holes are provided in a sealing body that seals an outer can, liquid is injected from one liquid injection hole, and exhaust is discharged from another liquid injection hole. A technique for reducing the pressure inside the outer can is disclosed.

  However, in the technique disclosed in Patent Document 1, bubbles are generated when the electrolyte is injected from above, so that the exchange of gas and electrolyte does not proceed smoothly inside the outer can and the sealing body. The problem that the liquid time becomes long occurs.

  In order to solve the above problem, Patent Document 2 discloses that a hole is provided in each of the bottom of the container and a sealing member that seals the opening of the container, liquid is injected from the hole in the bottom of the container, and sealing is performed. A technique is disclosed in which the inside of the container is decompressed by exhausting air from the hole of the stopper member.

  Patent Document 3 discloses a configuration in which a plurality of liquid injection / exhaust ports are provided at the position of the inner wall surface of the package facing the winding end surface of the pole group so that the electrolyte can be injected and the gas in the package can be exhausted. Has been.

  Patent Document 4 discloses a technique for injecting a non-aqueous electrolyte into a case where the pressure reduced in the electrode body drying step is maintained. In addition, the nonaqueous electrolyte battery according to Patent Document 4 includes a hole (exhaust port) connected to a vacuum pump and a hole (injection port) connected to an electrolyte injection device.

Japanese Patent Laid-Open No. 10-241741 (published on September 11, 1998) JP 2005-251738 A (published on September 15, 2005) Japanese Patent Laid-Open No. 2001-273844 (published on October 5, 2001) JP 2003-217669 A (published July 31, 2003)

  In any of the techniques disclosed in Patent Documents 1 to 4, there is a risk that the pressure reduction becomes excessive immediately after the pressure reduction inside the battery can is started. Along with this, the electrolyte having a low boiling point volatilizes. When the electrolyte is volatilized, gas is generated and this time the pressure rises. As described above, it is difficult to properly control the pressure (vacuum degree) inside the battery can, and the composition of the electrolytic solution is shifted due to the volatilization of the electrolytic solution, resulting in unstable quality. There is a risk of becoming.

  In addition, the path between the hole provided in the battery can for reducing the pressure and the vacuum pump for reducing the pressure is generally composed of a thin vacuum pipe. When such a vacuum pipe is used, Severe pressure adjustment to the inside of the battery can is required, and the pressure adjustment is difficult.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid injection device and a liquid injection method for a non-aqueous secondary battery that facilitates pressure control inside the battery can. It is in.

  In order to solve the above problems, the liquid injection device according to the present invention includes an electrolyte solution, an electrode laminate in which a positive electrode plate and a negative electrode plate are laminated via a separator, and the electrolyte solution and the electrode laminate. A battery can accommodated therein, wherein the battery can functions as an inlet for injecting the electrolyte into the battery can and exhausts the gas inside the battery can. When producing a non-aqueous secondary battery having a plurality of holes having the function of the exhaust port, the electrolyte is injected into the battery can from one of the two holes, A liquid injection device that exhausts the inside of the battery can from the other of the two holes to reduce the pressure inside the battery can, and includes a vacuum pump that performs the pressure reduction and the other of the two holes. Inserted and exhausted gas inside the battery can from the other side of the hole And a vacuum line that is provided between the vacuum pump and the nozzle and is a path for performing pressure reduction by the vacuum pump, and one end is connected to the nozzle side in the vacuum line, and the other end Is connected to the vacuum pump side of the vacuum line, and includes a pressure adjustment mechanism including a pressure adjustment container that suppresses pressure fluctuations in the battery can and in the vacuum line.

  Further, in order to solve the above problems, the liquid injection method of the present invention includes an electrolyte solution, an electrode laminate in which a positive electrode plate and a negative electrode plate are laminated via a separator, the electrolyte solution, and the electrode laminate. A battery can in which a body is housed, and the battery can functions as an inlet for injecting the electrolyte into the battery can and exhausts the gas inside the battery can. When producing a non-aqueous secondary battery having a plurality of holes having an exhaust port function, the electrolyte is injected into the battery can from one of the two holes. An injection method for exhausting the inside of the battery can from the other of the two holes and reducing the pressure inside the battery can, wherein when the pressure is reduced, the inside of the battery can and the above Pressure that suppresses pressure fluctuations in the vacuum line, which is the path for decompression It is characterized by using the pressure adjusting mechanism having an integer vessel.

  According to said structure, the pressure adjustment mechanism is comprised using the principle of operation of a buffer tank, and suppresses that the pressure of the inside of a battery can and a vacuum line changes rapidly.

  That is, when the vacuum line is depressurized, the inside of the pressure adjustment container is also depressurized. As a result, the pressure fluctuation in the vacuum line becomes gentler than the pressure fluctuation in the case where the vacuum line is decompressed independently without providing the pressure adjusting mechanism. In this way, the pressure adjusting mechanism can gently change the pressure inside the vacuum line and thus the battery can.

  By performing liquid injection in a non-aqueous secondary battery using a liquid injection device equipped with a pressure adjustment mechanism, it is possible to reduce the possibility of excessive pressure reduction immediately after starting the pressure reduction inside the battery can. . In connection with this, it can suppress that an electrolyte solution with a low boiling point volatilizes. In addition, even if the electrolytic solution volatilizes and gas is generated, an increase in pressure caused by this can be suppressed, and it is easy to start reducing pressure again. As described above, it is easy to appropriately control the pressure (vacuum degree) inside the battery can, and the quality of the electrolyte can be unstable due to deviation in the composition of the electrolyte due to the volatilization of the electrolyte. The risk of becoming can be reduced.

  In addition, according to the above configuration, the vacuum line is generally composed of a thin vacuum pipe, but even when such a vacuum pipe is used, severe pressure adjustment with respect to the inside of the battery can is performed. It is not required and the pressure adjustment is easy.

  Moreover, in the liquid injection device of the present invention, it is preferable that the volume of the pressure adjusting container is at least twice the volume of the battery can.

  The volume of the pressure adjusting container is preferably sufficiently large with respect to the volume of the battery can for injecting liquid. Thereby, compared with the pressure fluctuation inside the battery can, the pressure fluctuation inside the pressure regulation container can be made sufficiently small, so that the operation of the pressure regulation mechanism can be further stabilized. The standard of the volume of a pressure regulation container is more than twice the volume of a battery can.

  Further, in the liquid injection device according to the present invention, the pressure adjusting mechanism includes a cooling mechanism that cools the pressure adjusting container to lower the temperature inside the pressure adjusting container, and a liquid accumulated in the bottom of the pressure adjusting container. Is preferably provided with a drain for discharging the pressure to the outside of the pressure regulating container.

  According to said structure, when the electrolyte solution inside a battery can volatilizes and penetrate | invades into a vacuum line, this electrolyte solution is liquefied by cooling with a cooling mechanism, and is discharged | emitted from a drain. Thereby, it is suppressed that the electrolyte which accidentally entered the vacuum line reaches the vacuum pump. In general, since the electrolytic solution contains fluorine, when it reaches the vacuum pump, it reacts with moisture contained in the atmosphere and may damage the vacuum pump. By reliably discharging the electrolytic solution from the drain, it is possible to reduce factors that cause damage to the vacuum pump.

  In the liquid injection method of the present invention, the electrolyte is injected into the battery can from one of any two holes, and the inside of the battery can is exhausted from the other of the two holes. After reducing the pressure inside the battery can, the electrolyte is injected into the battery can from the other of the two holes, and the exhaust inside the battery can is discharged from one of the two holes. To reduce the pressure inside the battery can.

  According to the above method, since the liquid injection can be performed in the two holes, it is easy to uniformly impregnate the electrode laminate with the electrolytic solution.

  As described above, the liquid injection device of the present invention includes an electrolyte, an electrode laminate in which a positive electrode plate and a negative electrode plate are laminated via a separator, and a battery in which the electrolyte and the electrode laminate are accommodated. And the battery can has a function of an inlet for injecting the electrolytic solution into the battery can and a function of an exhaust port for exhausting the gas inside the battery can. When producing a non-aqueous secondary battery having a plurality of holes, the electrolyte is injected into the battery can from one of the two holes, and the two holes A liquid injection device for evacuating the inside of the battery can from the other side to reduce the pressure inside the battery can, the vacuum pump performing the pressure reduction, and being inserted into the other of the two holes, the battery A nozzle for exhausting the gas inside the can from the other side of the hole, and the vacuum A vacuum line that is provided between the nozzle and the nozzle and is a path for performing pressure reduction by the vacuum pump, one end is connected to the nozzle side in the vacuum line, and the other end is the vacuum line And a pressure adjusting mechanism including a pressure adjusting container for suppressing pressure fluctuations in the inside of the battery can and the vacuum line.

  The liquid injection method of the present invention includes an electrolyte, an electrode laminate in which a positive electrode plate and a negative electrode plate are laminated via a separator, a battery can in which the electrolyte and the electrode laminate are accommodated, The battery can has a function of an inlet for injecting the electrolytic solution into the battery can and a function of an exhaust port for exhausting the gas inside the battery can. When producing a non-aqueous secondary battery having a plurality of holes, the electrolyte is injected into the battery can from one of the two holes, and from the other of the two holes. A liquid injection method for evacuating the inside of the battery can and reducing the pressure inside the battery can, wherein when the pressure is reduced, the inside of the battery can and a vacuum that is a path for performing the pressure reduction Pressure adjustment mechanism with a pressure adjustment container that suppresses pressure fluctuations in the line Used.

  Therefore, there is an effect that the pressure inside the battery can is easily controlled.

It is a perspective view which shows the structure of the non-aqueous secondary battery which concerns on one embodiment of this invention. It is a graph which shows the comparative result of Examples 1-3 and a comparative example. It is a perspective view which shows the structure of the non-aqueous secondary battery which concerns on the 1st modification with respect to FIG. It is a perspective view which shows the structure of the non-aqueous secondary battery which concerns on the 2nd modification with respect to FIG. It is a perspective view which shows the structure of the non-aqueous secondary battery as a comparative example of the non-aqueous secondary battery shown in FIG. It is a perspective view which shows the structure of the principal part of the liquid injection apparatus in the non-aqueous secondary battery which concerns on one embodiment of this invention. It is a figure which shows the image of the liquid injection apparatus in the non-aqueous secondary battery which concerns on a prior art, and the liquid injection method. It is a perspective view which shows the specific example of a structure of a pressure adjustment mechanism. It is a perspective view which shows the structure which injects using a decompression chamber. It is a perspective view which shows the structure which simplified the liquid injection apparatus shown in FIG. The example of the opening / closing timing of a solenoid valve and a pressure regulation valve at the time of liquid injection by the liquid injection apparatus shown in FIG. 6 is shown. FIG. 11 shows an example of the opening / closing timings of the electromagnetic valve and the pressure regulating valve during liquid injection by the liquid injection apparatus shown in FIG. 10.

[Non-aqueous secondary battery and its injection method]
[Basic configuration]
FIG. 1 is a perspective view showing a configuration of a non-aqueous secondary battery according to the present embodiment.

  A non-aqueous secondary battery 1 shown in FIG. 1 includes a battery can 2, an electrode laminate 3, a current collecting terminal 4, a heat shrink film 5, and an external terminal 6.

  In FIG. 1, three directions perpendicular to each other, the X direction, the Y direction, and the Z direction, are defined. The battery can 2 of the non-aqueous secondary battery 1 is roughly a rectangular parallelepiped. Each surface constituting the rectangular parallelepiped is parallel to any two of the X direction, the Y direction, and the Z direction.

  The battery can 2 is formed by pressing a metal plate, for example, and includes a container-like case 2a and a lid member 2b. The material of the battery can 2 is iron, nickel-plated iron, stainless steel, aluminum, or the like. In addition, two holes 7 are provided in the lid member 2b. Details of the hole 7 will be described later.

  When the non-aqueous secondary battery 1 is used, the lid member 2b is positioned on the upper surface of the non-aqueous secondary battery 1 (battery can 2).

  The electrode laminate 3 is housed inside the battery can 2 and is not shown for convenience. However, a plurality of laminates (stacking units) in which a positive electrode plate and a negative electrode plate are laminated via a separator are provided. Layers are laminated. In the non-aqueous secondary battery 1, the electrode laminate 3 is a substantially hexahedron, but the shape of the electrode laminate itself is not particularly limited.

  For convenience, the electrolyte solution is not shown in FIG. 1, but the electrolyte solution is accommodated in the battery can 2 in which the electrode laminate 3 is accommodated. And after this accommodation, the hole 7 is closed and the nonaqueous secondary battery 1 is completed.

  Two current collecting terminals 4 are provided, one of which is electrically connected to the positive electrode plate, and the other is electrically connected to the negative electrode plate.

  In addition, in the non-aqueous secondary battery 1, in other words, the two current collecting terminals 4 are, in other words, the surface constituting one end of the electrode laminate 3 and the surface constituting the other end of the electrode laminate 3 in the X direction. The non-aqueous secondary battery 1 is provided so as to be opposed to each other with the electrode laminate 3 interposed in the horizontal direction.

  The heat-shrinkable film (film material) 5 is coated on the four surfaces of the electrode laminate 3 on which the current collecting terminals 4 are not provided. Specifically, the heat-shrinkable film (film material) 5 It is rolled up. The heat-shrinkable film 5 is made of a material that does not penetrate the electrolyte solution. For this reason, the electrolytic solution does not soak into the electrode laminate 3 from the portion of the electrode laminate 3 (typically, the above four surfaces) covered with the heat shrink film 5. As the heat shrink film 5, for example, a material containing polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), or polyolefin (PO) can be preferably used.

  Two external terminals 6 are provided, and each of the external terminals 6 is electrically connected to one of the corresponding two current collecting terminals 4.

  In the non-aqueous secondary battery 1, the two external terminals 6 relate to the surface constituting one end of the battery can 2 and the surface constituting the other end of the battery can 2 in the X direction. The secondary battery 1 is provided so as to be opposed to each other across the battery can 2 in the horizontal direction when the secondary battery 1 is used.

  As described above, two holes 7 are provided in the lid member 2b of the battery can 2. The hole 7 has a function of an inlet for injecting an electrolyte into the battery can 2 (that is, performing injection), and a function of an outlet for exhausting the gas inside the battery can 2. It is what has.

  The hole 7 is provided at a position that does not overlap with the electrode stack 3 housed inside the battery can 2. Moreover, it is preferable that the hole 7 is provided at a position that does not overlap with the current collecting terminal 4.

  Specifically, as shown in FIG. 1, the hole portion 7 includes at least the electrode stack 3, preferably the electrode stack 3 and the electrode stack 3. The electric terminal 4 is provided so as not to overlap.

  In the nonaqueous secondary battery 1, the separation distance D <b> 1 between the two hole portions 7 is larger than the dimension D <b> 2 of the electrode laminate 3 in the direction parallel to the line segment connecting the two hole portions 7.

[Specific example of method for producing non-aqueous secondary battery]
A specific example of a method for manufacturing the non-aqueous secondary battery according to this embodiment will be described below.

[Production of positive electrode plate]
LiFePO4 (90 parts by weight) as a positive electrode active material, acetylene black (5 parts by weight) as a conductive material, and polyvinylidene fluoride (5 parts by weight) as a binder are mixed. To this, N-methyl-2-pyrrolidone as a solvent is appropriately added to disperse each material, thereby preparing a slurry. This slurry was uniformly applied on both sides of an aluminum foil (thickness 20 μm) as a positive electrode current collector and dried, then compressed by a roll press, cut into a predetermined size, and a plate-like positive electrode plate was obtained. Produced.

  The produced positive electrode plate has a size of 145 mm × 298 mm and a thickness of 230 μm. A stacking unit is manufactured using nine of the positive plates.

[Production of negative electrode plate]
Natural graphite (90 parts by weight) as a negative electrode active material and polyvinylidene fluoride (10 parts by weight) as a binder are mixed. To this, N-methyl-2-pyrrolidone as a solvent is appropriately added to disperse each material, thereby preparing a slurry. The slurry was uniformly applied on both sides of a copper foil (thickness 16 μm) as a negative electrode current collector and dried, then compressed by a roll press, cut into a predetermined size, and a plate-like negative electrode plate was obtained. Produced.

  The produced negative electrode plate has a size of 153 mm × 306 mm and a thickness of 146 μm. A stacking unit is prepared using 10 negative electrode plates.

[Preparation of separator]
As a separator, a polyethylene film having a size of 155 mm × 311 mm and a thickness of 25 μm was produced.

[Preparation of non-aqueous electrolyte]
1 mol / L of LiPF ₆ was dissolved in a mixed solution (solvent) in which ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed at a volume ratio of 30:70 to prepare a nonaqueous electrolytic solution.

[Production of battery cans]
As a material for the container-like case 2a and the lid member 2b constituting the battery can 2, a nickel-plated iron plate was used. Further, the battery can 2 has a thickness of 0.8 mm, a longitudinal direction × short direction × depth (inside dimension) of 330 mm × 157 mm × 41 mm, and has two opening / closing holes 7 in the lid member 2b. Provided. Further, in order to make the lid member 2 b closely contact with the upper surface of the electrode laminate 3, the lid member 2 b has a plate-like configuration that fits inside the battery can 2 instead of a flat plate shape. When the dish-shaped lid member 2b is used, the lid member 2b can be prevented from moving when the lid member 2b is welded, so that the welding operation is facilitated. Moreover, it becomes possible to easily cope with a change in the thickness of the electrode laminate 3 to be accommodated by changing the amount of the dish-shaped drop in the lid member 2b. Furthermore, it is preferable that the lid member 2b has a dish shape because the strength of the lid member 2b and the strength of the battery can 2 can be improved.

[Assembly of secondary battery]
A positive electrode plate and a negative electrode plate are alternately laminated via a separator. At that time, 9 positive plates, 10 negative plates, and 18 separators are laminated so that the negative plate is located outside the positive plate. As a configuration in which a polyethylene film as the heat-shrinkable film 5 having the same thickness of 25 μm as that of the separator is wound, a stacking unit is manufactured, and the stacking unit is stacked in eight stages to form the electrode stack 3.

  As described above, the size of the separator interposed between the positive electrode plate and the negative electrode plate is 155 mm × 311 mm, which is slightly larger than the positive electrode plate (145 mm × 298 mm) and the negative electrode plate (153 mm × 306 mm). It is. Thereby, the active material layer formed on the positive electrode plate and the negative electrode plate can be reliably coated. Moreover, the connection piece of the current collection terminal 4 was connected to the current collector exposed part of the positive electrode and the current collector exposed part of the negative electrode, both of which are not wound with the heat shrink film 5.

  The electrode laminate 3 to which the current collector terminal 4 is connected is accommodated in the container-like case 2a, the current collector terminal 4 and the external terminal 6 are connected, the lid member 2b is attached, and the electrode laminate 3 is sealed. At this time, all of the hole portions 7 are provided in the lid member 2b at positions where they do not overlap any of the accommodated electrode laminate 3 and the current collecting terminal 4. And the nonaqueous electrolyte solution was inject | poured in the inside of the battery can 2 from the hole 7, and liquid injection was performed. At this time, the liquid injection was performed from the other hole 7 while exhausting from one hole 7 to make the inside of the battery can 2 in a reduced pressure atmosphere. After the injection, the two holes 7 were sealed to produce a non-aqueous secondary battery.

[Example 1]
The non-aqueous secondary battery 1 was produced by the method for producing the non-aqueous secondary battery described above.

  Further, the battery can 2 was placed such that the X direction in FIG. 1 was the vertical direction (the direction of gravity), and liquid injection was performed.

  When the battery can 2 is placed so that the X direction in FIG. 1 is the vertical direction, the heights of the two hole portions 7 are different and the upper hole portion 7 is positioned higher than the electrode laminate 3. Exhaust is performed from the upper hole 7 and liquid injection is performed from the lower hole 7.

[Example 2]
Based on the above method for producing a non-aqueous secondary battery, the following non-aqueous secondary battery (hereinafter referred to as non-aqueous secondary battery 1a) was produced.

  That is, the non-aqueous secondary battery 1a has the same configuration as the non-aqueous secondary battery 1 except that the heat shrink film 5 is omitted.

  Further, the battery can 2 was placed so that the X direction in FIG.

[Example 3]
Based on the above method for producing a non-aqueous secondary battery, a non-aqueous secondary battery 1a was produced in the same manner as in Example 2.

  However, the battery can 2 was placed so that the Z direction in FIG.

[Comparative example]
Based on the above method for producing a non-aqueous secondary battery, the following non-aqueous secondary battery (hereinafter referred to as non-aqueous secondary battery 1b) was produced.

  That is, the non-aqueous secondary battery 1b has the hole 7 omitted, and a hole (hole 7 ′ shown in FIG. 1) is provided at a position overlapping the electrode laminate 3 and the current collecting terminal 4. The configuration is the same as that of the non-aqueous secondary battery 1a.

  Further, the battery can 2 was placed so that the Z direction in FIG.

[Comparison results of Examples 1 to 3 and Comparative Example]
FIG. 2 is a graph showing the comparison results of Examples 1 to 3 and the comparative example, and is a graph showing the relationship between the cycle and the capacity retention rate. Specifically, FIG. 2 shows the results of the cycle test.

  Incidentally, in the comparative example, the battery capacity became 0 between the 100th cycle and the 150th cycle. This is considered to be caused by an internal short circuit of the non-aqueous secondary battery 1b.

[Operational effects of the configuration of the non-aqueous secondary battery 1]
By providing a hole 7 at a position where it does not overlap with the electrode laminate 3 accommodated in the battery can 2, and pouring the liquid from the hole 7, the electrolyte does not directly contact the electrode laminate 3. It reaches the bottom of the battery can 2 at the time of liquid. As a result, the portion where the electrolytic solution is intensively supplied in the electrode laminate 3 is eliminated, and it is easy to uniformly impregnate the electrode laminate 3 with the electrolytic solution. When the hole 7 does not overlap with the current collector terminal 4, it is possible to more uniformly impregnate the electrode laminate 3 with the electrolytic solution.

  In the structure of the nonaqueous secondary battery 1, the electrode stack 3 is not densely accommodated inside the battery can 2. In other words, in a state where the electrode laminate 3 is accommodated inside the battery can 2, a space where the electrode laminate 3 does not exist is formed inside the battery can 2. What is necessary is just to provide the hole part 7 so that it may overlap with this space.

  Moreover, the hole 7 is provided in the lid member 2b. In other words, when the non-aqueous secondary battery 1 is used, the hole 7 is positioned on the upper surface of the non-aqueous secondary battery 1 (battery can 2). For this reason, it can suppress that electrolyte solution contacts the hole part 7 or the part which block | closed it. As a result, it is possible to reduce the possibility that the electrolytic solution leaks from the battery can 2.

  In addition, since it is not necessary to position the hole 7 on the bottom surface during the injection, the possibility of the electrolyte adhering to the vicinity of the hole 7 when the injection nozzle is removed from the hole 7 is reduced. Can do. Therefore, it is possible to reduce factors that adversely affect the sealing of the hole 7.

  In particular, when pouring with the battery can 2 placed such that the Z direction in FIG. 1 is the vertical direction, it is not necessary to plug a rubber plug so that the electrolyte does not spill to the hole 7 sealing. As a result, it is possible to reduce the risk of leakage of the electrolyte due to deterioration of the rubber plug and contamination of foreign matter inside the battery can 2.

  On the other hand, when liquid injection is performed with the battery can 2 placed such that the X direction in FIG. 1 is the vertical direction, the heights of the two hole portions 7 are different and the upper hole portion 7 is more than the electrode laminate 3. It is preferable to perform the injection by determining the direction of the battery can 2 so as to be at a high position.

  In this case, exhausting from the upper hole 7 makes it possible to immerse the entire surface of the electrode laminate 3 in the electrolytic solution, so that the electrode laminate 3 can be uniformly impregnated with the electrolyte more reliably. Is possible. On the other hand, it is preferable that the lower hole 7 for injecting the liquid is as low as possible. This is because it is possible to further reduce the possibility that the electrolytic solution directly hits the electrode laminate 3 during injection. If the distance D1 between the two holes 7 is sufficiently large, it is easy to position the lower hole 7 sufficiently low.

  Further, by using the heat shrinkable film 5, the electrolytic solution can be obtained from only the portion of the electrode laminate 3 that is not covered by the heat shrinkable film 5, that is, the two surfaces provided with the current collecting terminals 4 in the electrode laminate 3. Soak up.

  As a result, particularly when the non-aqueous secondary battery 1 is large, it is easy to impregnate the electrolyte solution near the center of the electrode laminate 3, so that the electrolyte solution can be evenly and uniformly applied to the electrode laminate 3. Can be soaked.

  As described above, the nonaqueous secondary battery 1 has an effect that it is possible and easy to make the electrode laminate 3 soaked with the electrolyte uniformly. With this effect, it is possible to increase the speed of injection, and it is also possible to suppress a reduction in battery capacity that accompanies repeated use of the battery.

  In the non-aqueous secondary battery 1, the two hole portions 7 are both round holes, but the shape of the hole portion 7 is not limited to a round hole, and any shape such as a square hole may be used. Also good.

  Further, in the non-aqueous secondary battery 1, the two hole portions 7 are provided at positions that do not overlap with the electrode laminate 3, and are further provided at positions that do not overlap with the current collector terminals 4. preferable. However, only one of the two hole portions 7 may be provided at this position.

  Further, in the non-aqueous secondary battery 1, the hole 7 is provided in the lid member 2b, but it is not necessarily required to be provided in the lid member 2b. That is, it is preferable that the hole 7 is provided at a position higher than the liquid level of the electrolytic solution when the non-aqueous secondary battery 1 is used.

  In the nonaqueous secondary battery 1, the number of the hole portions 7 is two, but the number of the hole portions 7 is not limited to two, and may be three or more.

  Moreover, in the non-aqueous secondary battery 1, the heat shrink film 5 is not an essential configuration and may be omitted.

  In addition, the height of the liquid level of the electrolytic solution inside the battery can 2 at the time of liquid injection is such that the liquid level does not rise too much through a space where the electrode stack 3 does not exist. Control in consideration of penetration.

[Modification 1]
FIG. 3 is a perspective view showing a configuration of a non-aqueous secondary battery according to a first modification to FIG.

  The non-aqueous secondary battery 11 shown in FIG. 3 is different from the non-aqueous secondary battery 1 shown in FIG. 1 in the positions of the two current collecting terminals 4 and the two external terminals 6, and other configurations are shown in FIG. This is the same as the non-aqueous secondary battery 1 shown.

  That is, in the nonaqueous secondary battery 11, the two current collecting terminals 4 are both arranged on the surface constituting one end of the electrode stack 3 in the X direction, in other words, on one surface of the electrode stack 3. Is provided.

  Similarly, in the non-aqueous secondary battery 11, the two external terminals 6 are both provided on the surface constituting one end of the battery can 2 in the X direction, in other words, on one surface of the battery can 2. It has been.

[Modification 2]
FIG. 4 is a perspective view showing a configuration of a non-aqueous secondary battery according to a second modification to FIG.

  In the non-aqueous secondary battery 21 shown in FIG. 4, the two external terminals 6 are both provided side by side on the upper surface (typically, the lid member 2 b) of the battery can 2. In the non-aqueous secondary battery 21, the two current collecting terminals 4 are in the same position as the non-aqueous secondary battery 1 shown in FIG. 1.

  The current collecting terminal 4 and the external terminal 6 are electrically connected by a wiring 8, and the wiring 8 is routed near the inner wall of the battery can 2. With this configuration, when the two can holes 7 are different in height and the battery can 2 is placed such that the upper hole 7 is positioned higher than the electrode laminate 3, the liquid injection is performed (Example 1 and 2), the strength of the current collecting terminal 4, the external terminal 6, and the wiring 8 can be increased. This is because it is possible to absorb an impact by the wiring 8 by giving a margin to the length of the wiring 8.

  On the contrary, as shown in FIG. 5, when the current collecting terminal 4, the external terminal 6 and the wiring 8 are provided so as to connect the current collecting terminal 4 and the external terminal 6 with the shortest distance, the battery can as described above. There is a concern that the strength of the current collecting terminal 4, the external terminal 6, and the wiring 8 in the case of placing 2 is lowered.

  Furthermore, in the example shown in FIG. 4, it becomes easier to increase the connection area between the electrode laminate 3 and the current collecting terminal 4 than the example shown in FIG. 5. Therefore, the example shown in FIG. 4 has higher strength. Moreover, the electrode laminated body 3 and the current collection terminal 4 have a line-shaped connection surface with a length of several millimeters x several centimeters. Therefore, when the battery is erected so that the plurality of hole portions 7 are arranged vertically when pouring, the example shown in FIG. 4 is more connected to the electrode stack 3 and the current collecting terminal 4 than the example shown in FIG. Since the stress applied to the part can be received over a wide area with respect to gravity, the strength is increased.

[Summary]
In addition, the non-aqueous secondary battery which concerns on this invention can also be interpreted as follows.

  Without providing the hole 7 at the bottom of the battery can 2 when the battery is used, the electrolyte can be easily soaked into the electrode laminate 3 in one direction from the bottom to the top of the battery can 2 at the time of liquid injection. Become. For this reason, since a possibility that electrolyte solution may contact the part which plugged up hole 7 can be reduced, the reliability of a battery improves.

  Although the hole part 7 is provided in the lid member 2b, the position of the hole part 7 and the position of the electrode laminate 3 are related so that the penetration in the one direction is easy.

  By defining the connection structure between the current collecting terminal 4 and the external terminal 6, a battery can be set up, and further, the penetration in the one direction is facilitated.

  The lid member 2 b has a plurality of holes 7, and at least one of the holes 7 exists outside the electrode end of the electrode laminate 3. Thereby, the rapid decrease in capacity as in the above-described comparative example can be suppressed. This also facilitates penetration in the one direction.

  Further, the outermost layer of the electrode laminate 3 is provided with a heat shrink film 5 that does not allow electrolyte solution to pass therethrough. Thereby, since it can suppress that electrolyte solution penetrates into the electrode laminated body 3 from 4 surfaces covered with the heat contraction film 5 in the electrode laminated body 3, it can perform unidirectional liquid injection more reliably. it can.

  In addition, when the hole 7 is sealed, it is possible to prevent moisture from being mixed into the battery can 2 by sealing the metal plate by welding. Specifically, unlike the case where sealing is performed using a heat-sealing resin, it is possible to prevent moisture from being mixed into the battery can 2 for a long period of 10 years or longer.

  Further, as shown in FIG. 1 in particular, the distance D1 between the two holes 7 is set to be larger than the dimension D2 of the electrode laminate 3 in the direction parallel to the line segment connecting the two holes 7 as follows. There is an effect. That is, the possibility that the electrolyte injected into the battery can 2 from the one hole 7 flows out from the other hole 7 can be reduced.

[Liquid injection device and method for non-aqueous secondary battery]
[Task]
FIG. 7 is a diagram illustrating an image of a liquid injection device and a liquid injection method in a non-aqueous secondary battery according to the related art.

  The non-aqueous secondary battery 201 shown in FIG. 7 includes two holes 207a and 207b, which are provided on the upper surface of the battery can 202 and the bottom surface of the battery can 202, respectively.

  Then, by using the vacuum pump 166 to exhaust air from the hole 207a provided on the upper surface of the battery can 202, the hole provided on the bottom surface of the battery can 202 while maintaining the inside of the battery can 202 in a reduced pressure atmosphere. Inject liquid from 207b.

  Note that the “upper surface of the battery can 202” and the “bottom surface of the battery can 202” are the same when the liquid is injected and when the nonaqueous secondary battery 201 is used.

  However, in the liquid injection device and the liquid injection method in the non-aqueous secondary battery 201 according to FIG. 7, the pressure reduction may be excessive immediately after the vacuum pump 166 starts the pressure reduction inside the battery can 202. Along with this, the electrolyte having a low boiling point volatilizes. When the electrolyte is volatilized, gas is generated and this time the pressure rises. As described above, it is difficult to appropriately control the pressure (vacuum degree) inside the battery can 202, and the composition of the electrolytic solution is shifted due to volatilization of the electrolytic solution, resulting in unstable quality. There is a risk of becoming.

  In addition, the path 167 between the hole 207a and the vacuum pump 166 is generally formed by a thin vacuum pipe. When such a vacuum pipe is used, severe pressure adjustment to the inside of the battery can 202 is possible. It is required and the pressure adjustment is difficult.

[Configuration of liquid injection device]
FIG. 6 is a perspective view showing the configuration of the main part of the liquid injection device in the non-aqueous secondary battery according to the present embodiment.

  A liquid injection device 61 shown in FIG. 6 performs liquid injection in the non-aqueous secondary battery 101. In the non-aqueous secondary battery 101, the electrode stack 103 is accommodated in the battery can 102, and functions of an inlet and / or an exhaust port are provided on the bottom of the battery can 102 (preferably, the lid member 102 b). Two holes 107 are provided. As such a non-aqueous secondary battery 101, any one of the non-aqueous secondary battery 1 (see FIG. 1), the non-aqueous secondary battery 11 (see FIG. 3), and the non-aqueous secondary battery 21 (see FIG. 4). Needless to say, is preferably used.

  The liquid injection device 61 includes hopper tanks 62a and 62b, electromagnetic valves 63a to 63f, a pressure regulating container 64, a pressure regulating valve 65, a vacuum pump 66, a vacuum line 67, and liquid injection nozzles 68a and 68b. ing.

  The hopper tank 62a is connected to a path (electrolyte line) through which an electrolyte for injecting liquid from an electrolyte tank (not shown) passes. The electromagnetic valve 63a is provided in an electrolyte line connected to the hopper tank 62a, and opens the line when it is open and blocks the line when it is closed.

  The liquid injection nozzle 68a is connected to the hopper tank 62a. The electromagnetic valve 63c is provided in a path from the hopper tank 62a to the tip 68as of the liquid injection nozzle 68a, and opens the path when opened and blocks the path when closed.

  The hopper tank 62b is connected to the electrolyte line. The electromagnetic valve 63b is provided in an electrolyte line connected to the hopper tank 62b, and opens the line when it is open and blocks the line when it is closed.

  The liquid injection nozzle 68b is connected to the hopper tank 62b. The electromagnetic valve 63d is provided in a path from the hopper tank 62b to the tip 68bs of the liquid injection nozzle 68b, and opens the path when opened, and blocks the path when closed.

  The liquid injection nozzle 68a and the liquid injection nozzle 68b have their front end 68as and front end 68bs positioned and fixed in one hole 107, respectively. Both of the injection nozzle 68a and the injection nozzle 68b are a nozzle that injects the electrolyte supplied through the electrolyte line into the inside of the battery can 102 through the hole 107, and a gas inside the battery can 102 through the hole 107. It also has a nozzle for exhausting to the vacuum line 67.

  The vacuum line 67 is provided so as to branch from between the electromagnetic valve 63c and the tip 68as, and is provided so as to branch from between the solenoid valve 63d and the tip 68bs. The electromagnetic valve 63e is provided in a vacuum line 67 connected to the liquid injection nozzle 68a, and opens the line when it is open, and blocks the line when it is closed. The electromagnetic valve 63f is provided in a vacuum line 67 connected to the liquid injection nozzle 68b. The electromagnetic valve 63f opens the line when opened, and blocks the line when closed.

  One end of the pressure adjusting container 64 is connected to the liquid injection nozzles 68 a and 68 b in the vacuum line 67, and the other end is connected to the vacuum pump 66 side in the vacuum line 67. The pressure adjustment container 64 is configured using the operation principle of the buffer tank, and is a main part of a pressure adjustment mechanism for suppressing a sudden change in the pressure of the inside of the battery can 102 to the vacuum line 67. A detailed description of the pressure adjustment mechanism will be described later.

  The pressure regulating valve 65 makes it possible to reduce the pressure by the vacuum pump 66 when it is open, and disables the pressure reduction regardless of whether the electromagnetic valve 63e and the electromagnetic valve 63f are open or closed.

  The vacuum pump 66 is for realizing pressure reduction inside the battery can 102 through the vacuum line 67 in which the pressure regulating container 64 is interposed.

  FIG. 8 is a perspective view showing a specific example of the configuration of the pressure adjustment mechanism.

  As shown in FIG. 8, the pressure adjustment mechanism 81 includes electromagnetic valves 63e and 63f, a pressure adjustment container 64, a pressure regulating valve 65, a cooling mechanism 82, a drain 83, and a negative pressure relief valve 84.

  The cooling mechanism 82 lowers the temperature inside the pressure regulating container 64 by cooling the pressure regulating container 64. As the cooling mechanism 82, a cooling coil embedded in the pressure adjusting container 64, a mechanism for circulating cooling water in the vicinity of the outer wall of the pressure adjusting container 64, and the like can be used.

  The drain 83 includes a pipe (drain pipe) and a stopper (drain valve, drain cap), and is provided for discharging the liquid accumulated at the bottom of the pressure regulating container 64 to the outside of the pressure regulating container 64. It has been.

  The negative pressure relief valve 84 is opened when the pressure inside the pressure regulating container 64 becomes negative with respect to a predetermined value, so that the pressure inside the pressure regulating container 64 and the inside of the battery can 102 can be reduced. This prevents the pressure from becoming extremely low.

  At the time of liquid injection, first, the liquid injection nozzle 68 a is fixed to one hole 107, and the liquid injection nozzle 68 b is fixed to the other hole 107.

  And while injecting electrolyte solution into the inside of the battery can 102 from one hole 107 by the liquid injection nozzle 68a, the inside of the battery can 102 is exhausted from the other hole 107 by the liquid injection nozzle 68b.

  At this time, the electrolytic solution supplied to the hopper tank 62a through the electrolytic solution line is injected into the battery can 102 through the injection nozzle 68a. At this time, the inside of the battery can 102 is evacuated by the vacuum pump 66 through the vacuum line 67 from the liquid injection nozzle 68b, and the inside of the battery can 102 is decompressed.

  Here, as described above, the pressure adjustment mechanism 81 is configured using the operation principle of the buffer tank, and suppresses a sudden change in the pressure of the inside of the battery can 102 to the vacuum line 67.

  That is, when the vacuum line 67 is depressurized by the vacuum pump 66, the inside of the pressure regulating container 64 is also depressurized. As a result, the pressure fluctuation in the vacuum line 67 becomes milder than the pressure fluctuation in the case where the pressure adjustment mechanism 81 is not provided and the vacuum line 67 is decompressed alone. In this way, the pressure adjustment mechanism 81 can gently change the pressure inside the vacuum line 67 and thus the battery can 102.

  Immediately after starting the pressure reduction in the battery can 102 by the vacuum pump 66 by injecting the liquid into the non-aqueous secondary battery 101 using the liquid injection device 61 provided with the pressure adjustment mechanism 81, the pressure reduction becomes excessive. Can be reduced. In connection with this, it can suppress that an electrolyte solution with a low boiling point volatilizes. In addition, even if the electrolytic solution volatilizes and gas is generated, an increase in pressure caused by this can be suppressed, and it is easy to start reducing pressure again. As described above, it is easy to appropriately control the pressure (degree of vacuum) inside the battery can 102, and the quality of the electrolyte is unstable due to deviation of the composition of the electrolyte due to volatilization of the electrolyte. The possibility of becoming can also be reduced.

  Further, the vacuum line 67 is generally made of a thin vacuum pipe, but even when such a vacuum pipe is used, severe pressure adjustment to the inside of the battery can 102 is not required, and Pressure adjustment is easy.

  In addition, it is preferable that the volume of the pressure regulation container 64 is sufficiently large with respect to the volume of the battery can 102 which injects liquid. Thereby, compared with the pressure fluctuation inside the battery can 102, the pressure fluctuation inside the pressure regulation container 64 can be made sufficiently small, so that the operation of the pressure regulation mechanism 81 can be further stabilized. The standard of the volume of the pressure adjustment container 64 is twice or more the volume of the battery can 102.

  The pressure adjustment mechanism 81 includes a cooling mechanism 82 and a drain 83, which has the following advantages.

  That is, when the electrolyte inside the battery can 102 volatilizes and enters the vacuum line 67, the electrolyte is liquefied by being cooled by the cooling mechanism 82 and discharged from the drain 83. As a result, the electrolytic solution that accidentally enters the vacuum line 67 is prevented from reaching the vacuum pump 66. In general, since the electrolytic solution contains fluorine, when it reaches the vacuum pump 66, it reacts with moisture contained in the atmosphere and may damage the vacuum pump 66. By reliably discharging the electrolytic solution from the drain 83, it is possible to reduce factors that damage the vacuum pump 66.

  After injecting the electrolyte into the battery can 102 via the injection nozzle 68a and reducing the pressure inside the battery can 102 from the injection nozzle 68b, after injecting the electrolyte by half of the total injection volume, The operation of the injection nozzle 68a and the operation of the injection nozzle 68b are interchanged to perform injection.

  That is, while the electrolyte is injected into the inside of the battery can 102 from the other hole 107 by the liquid injection nozzle 68b, the inside of the battery can 102 is exhausted from the one hole 107 by the liquid injection nozzle 68a.

  At this time, the electrolytic solution supplied to the hopper tank 62b through the electrolytic solution line is injected into the battery can 102 through the injection nozzle 68b. At this time, the inside of the battery can 102 is exhausted by the vacuum pump 66 through the vacuum line 67 from the liquid injection nozzle 68a, and the inside of the battery can 102 is decompressed.

  Thereby, since the injection can be performed through the two hole portions 107, it is easy to uniformly impregnate the electrode laminate 103 with the electrolytic solution.

  FIG. 11 shows a more specific example of the opening / closing timings of the electromagnetic valves 63a to 63f and the pressure regulating valve 65 during the liquid injection by the liquid injection device 61. In this example, it is assumed that the vacuum pump 66 is always operating.

  First, in a state before the start of liquid injection, that is, in a standby state, all the electromagnetic valves 63a to 63f are closed and the pressure regulating valve 65 is opened.

  As shown in FIG. 6, when the battery can 102 is set, the hopper tank 62a is replenished with electrolyte. At this time, the amount of electrolyte replenished in the hopper tank 62a is half of the total amount of liquid injected into the battery can 102. At this time, the electromagnetic valve 63a is opened until the replenishment of the electrolytic solution to the hopper tank 62a is completed, and the electromagnetic valve 63f is opened until a desired pressure is obtained inside the battery can 102. The electromagnetic valves 63b to 63e are all closed, and the pressure regulating valve 65 is opened.

  Thereafter, the electromagnetic valve 63c is opened, and the electrolytic solution replenished to the hopper tank 62a is injected into the battery can 102 from the injection nozzle 68a through the one hole 107. Further, at this time, the electromagnetic valve 63b is opened, and the electrolytic solution is replenished to the hopper tank 62b. The amount of the electrolyte solution that is replenished to the hopper tank 62 b is half (the remaining) half of the total amount of liquid injected into the battery can 102. At this time, the electromagnetic valve 63f is initially closed, but is opened after a lapse of a fixed time (for example, after 15 seconds). The opening and closing of the pressure regulating valve 65 is controlled so as to adjust the pressure between the inside of the battery can 102 and the vacuum line 67 to an appropriate pressure. The electromagnetic valves 63a, 63d, 63e are all closed.

  Thereafter, the inside of the battery can 102 is further depressurized (evacuated). At this time, the electromagnetic valve 63e is opened inside the battery can 102 until a desired pressure is obtained. The electromagnetic valves 63a to 63d and 63f are all closed, and the pressure regulating valve 65 is opened.

  Thereafter, the electrolytic solution replenished in the hopper tank 62b is injected into the inside of the battery can 102 from the injection nozzle 68b through the other hole 107. At this time, the electromagnetic valve 63d is opened, and the electromagnetic valve 63e is initially closed, but is opened after, for example, 15 seconds. The opening and closing of the pressure regulating valve 65 is controlled so as to adjust the pressure between the inside of the battery can 102 and the vacuum line 67 to an appropriate pressure. The solenoid valves 63a to 63c and 63f are all closed.

[Configuration of liquid injection device (simple configuration)]
FIG. 10 is a perspective view showing a simplified configuration of the liquid injection device shown in FIG.

  The liquid injection device 61 ′ shown in FIG. 10 is a simplified version of the liquid injection device 61 shown in FIG.

  Specifically, the liquid injection device 61 ′ includes a hopper tank 62a, electromagnetic valves 63a, 63c, 63f, liquid injection nozzles 68a and 68b, a vacuum line 67 connected to the liquid injection nozzle 68b, pressure, among the configurations of the liquid injection device 61. A regulating container 64, a pressure regulating valve 65, and a vacuum pump 66 are provided.

  The liquid injection device 61 ′ injects the electrolytic solution supplied to the hopper tank 62 a through the electrolytic solution line into the battery can 102 through the liquid injection nozzle 68 a in the same manner as the liquid injection device 61. In addition, the liquid injection device 61 ′ exhausts the inside of the battery can 102 by the vacuum pump 66 through the vacuum line 67 from the liquid injection nozzle 68 b in the same manner as the liquid injection device 61, and reduces the internal pressure of the battery can 102. Do.

  Thereby, also in liquid injection apparatus 61 ', the effect similar to liquid injection apparatus 61 can be acquired.

  In addition, after the half amount of the electrolytic solution to be injected is injected by the above method, the injection nozzle 68 b is fixed to one hole 107, and the injection nozzle 68 a is fixed to the other hole 107.

  Accordingly, the electrolyte solution can be injected into the inside of the battery can 102 from the other hole 107 by the liquid injection nozzle 68a, and the exhaust inside the battery can 102 from the one hole 107 by the liquid injection nozzle 68b. Can be performed.

  Also by this, since it is possible to inject the liquid in the two hole portions 107, it becomes easy to uniformly impregnate the electrode laminate 103 with the electrolytic solution.

  FIG. 12 shows a more specific example of the opening / closing timing of the electromagnetic valves 63a, 63c, 63f and the pressure regulating valve 65 at the time of liquid injection by the liquid injection device 61 ′. In this example, it is assumed that the vacuum pump 66 is always operating.

  In the standby state, all the electromagnetic valves 63a, 63c, and 63f are closed, and the pressure regulating valve 65 is opened.

  When the battery can 102 is set as shown in FIG. 10, the electrolyte is replenished to the hopper tank 62a. At this time, the amount of the electrolyte replenished to the hopper tank 62a is the total amount of liquid injected into the battery can 102. At this time, the electromagnetic valve 63a is opened until the replenishment of the electrolytic solution to the hopper tank 62a is completed, and the electromagnetic valve 63f is opened until a desired pressure is obtained inside the battery can 102. The electromagnetic valve 63c is closed and the pressure regulating valve 65 is opened.

  Thereafter, the electrolyte replenished in the hopper tank 62a is injected into the battery can 102 from the injection nozzle 68a through the one hole 107. At this time, the electromagnetic valve 63c is opened, and the electromagnetic valve 63f is initially closed, but is opened after elapse of 15 seconds, for example.

[Another specific example of a method for producing a non-aqueous secondary battery]
[Production of positive electrode plate]
A positive electrode plate was produced in the same manner as the specific example of the method for producing the non-aqueous secondary battery described above.

[Production of negative electrode plate]
A negative electrode plate was produced in the same manner as the specific example of the method for producing the non-aqueous secondary battery described above.

[Preparation of separator]
The separator was produced in the same manner as the specific example of the method for producing the non-aqueous secondary battery described above.

[Preparation of non-aqueous electrolyte]
A non-aqueous electrolyte was prepared in the same manner as the specific example of the method for manufacturing the non-aqueous secondary battery described above.

[Production of battery cans]
As a material for the container-like case 102a and the lid member 102b constituting the battery can 102, a SUS (Steel Special Use Stainless) plate was used. The container-like case 102a has a thickness of 0.8 mm, and a longitudinal direction × short direction × depth (inside dimension) is 330 mm × 157 mm × 41 mm. The lid member 102b has a thickness of 0.4 mm. Similarly to the above-described specific example of the method for manufacturing the non-aqueous secondary battery, the lid member 102 b has a dish-shaped configuration that fits inside the battery can 102.

  Two hole portions 107 of the battery can 102 are provided in the lid member 102b, and circular holes each having a diameter of 2.5 mm are spaced apart from each other (ie, corresponding to the distance D1 shown in FIG. 1) by 328.4 mm. It was provided to become.

[Assembly of secondary battery]
The secondary battery was assembled in the same manner as the specific example of the method for manufacturing the non-aqueous secondary battery described above, and five non-aqueous secondary batteries 101 were manufactured for each of the following examples.

[Example A]
A liquid injection device 61 'is used. When injecting the non-aqueous electrolyte while reducing the pressure inside the battery can 102 with the vacuum pump 66, the pressure inside the battery can 102 is once reduced to 10 kPa. Thereafter, the liquid injection nozzle 68b performs exhaust so as to keep the pressure inside the battery can 102 constant through a pressure adjustment mechanism 81 that suppresses the pressure fluctuation inside the battery can 102 and improves the pressure controllability. The liquid injection was performed from the liquid injection nozzle 68a. The vacuum pump 66 preferably has an exhaust capacity of 20 liters per minute or more in order to shorten the time of decompression (initial vacuuming) performed before the injection.

[Example B]
A liquid injection device 61 is used. Half of the electrolyte to be injected performs the same operation as in Example A. The other half performs liquid injection by switching the operation of the liquid injection nozzle 68a and the operation of the liquid injection nozzle 68b. That is, the liquid injection nozzle 68a performs exhaust so as to keep the pressure inside the battery can 102 constant through the pressure adjusting mechanism 81 that suppresses the pressure fluctuation inside the battery can 102 and improves the pressure controllability. The liquid was injected from the liquid injection nozzle 68b.

[Comparative Example A]
When the inside of the battery can 102 is decompressed from one hole 107 by the vacuum pump 66 and the nonaqueous electrolyte is injected from the other hole 107, the pressure adjustment mechanism 81 is not passed through the one hole 107. The inside of the battery can 102 was depressurized (that is, using an apparatus comprising a vacuum pipe, a vacuum gauge, a solenoid valve, and a vacuum pump).

[Comparative Example B]
Using the decompression chamber 91 as shown in FIG. 9, the decompression chamber 91 and the inside of the battery can 102 were decompressed together, and then injection was performed using only one hole 107.

[Comparative Example C]
One hole was provided in the lid member of the battery can, and the decompression chamber 91 and the inside of the battery can were decompressed together using the decompression chamber 91, and then the liquid was injected from the hole.

[Comparison Results of Examples A to B and Comparative Examples A to C]
In Comparative Example C, the safety valve was cleaved as a result of the pressure inside the battery can rising due to the pressure of the gas generated with the injection.

  On the other hand, one non-aqueous secondary battery according to Example A, Example B, Comparative Example A, and Comparative Example B was produced, and a charge / discharge test was conducted at C rate: 0.1 C rate and 1 C rate. The discharge capacity was confirmed. Table 1 shows the 0.1 C rate discharge capacity, 1 C rate discharge capacity, rate characteristics defined by the following formula, and tact time required for injection.

    Rate characteristics = 1C rate discharge capacity / 0.1C rate discharge capacity

  As shown in [Table 1], in Examples A and B in which liquid was injected from the other hole 107 while reducing the inside of the battery can 102 from the one hole 107 via the pressure adjustment mechanism 81, When the 0.1 C rate discharge capacity was confirmed, good capacity was obtained in all cases. Also, in the rate characteristics, good results were obtained in Examples A and B, and Example B in particular had the best rate characteristics. Also in the tact time, Examples A and B were able to significantly reduce the time compared to Comparative Example B.

  On the other hand, in Comparative Example A, since the pressure control inside the battery can 102 was insufficient during the injection, the degree of vacuum inside the battery can 102 reached 1 kPa at the moment when the electromagnetic valve of the vacuum line was opened. have done. Thereafter, an attempt was made to control the inside of the battery can 102 to 10 kPa with a pressure regulating valve, but the pressure could not be controlled to a stable level. For this reason, a desired rate characteristic could not be obtained in the charge / discharge test. In addition, the electrolyte solution has entered from the inside of the battery can 102 into the vacuum line, so that a desired amount of electrolyte solution cannot be injected, and only a result of insufficient discharge capacity is obtained in the charge / discharge test. It was.

  In Comparative Example B, the injection was performed with the injection nozzle inserted into one hole 107 and the other hole 107 opened, but the pressure inside the battery can 102 was reduced. The pressure inside the chamber 91 has become higher. As a result, it was difficult to inject the electrolyte into the battery can 102 during the injection, and it was difficult to inject a specified amount of the electrolyte. For this reason, the penetration of the electrolytic solution into the electrode laminate 103 was insufficient, and a desired discharge capacity could not be obtained.

  In Comparative Example C, the pressure inside the battery can increased while the electrolytic solution was being pumped by the pump, the safety valve was cleaved, and the battery did not function.

  When liquid injection is performed using the decompression chamber 91, if the volume of the decompression chamber 91 is sufficiently larger than the capacity of the battery can 102 having two holes 107, the battery can 102 can be used using the pressure adjustment mechanism 81. It is considered possible to control the internal pressure (vacuum degree). On the other hand, compared with the case where the liquid injection device 61 is used, the gas flow inside the battery can 102 is reduced, so that it is not easy to sufficiently impregnate the electrode laminate 103 with the electrolytic solution.

[Overview of injection device and injection method for non-aqueous secondary batteries]
In addition, the liquid injection apparatus and the liquid injection method in the non-aqueous secondary battery according to the present embodiment can be interpreted as follows.

  Conventionally, the path of the vacuum line is narrow and it is difficult to control the pressure during injection, so it has been difficult to provide products with stable quality. In addition, when the injection is performed from the lower side of the non-aqueous secondary battery, there is a possibility that the hole is not sufficiently sealed by laser welding due to leakage of the electrolyte and adhesion of the electrolyte to the hole. It was.

  Therefore, the pressure can be easily stabilized by installing the pressure adjusting mechanism 81 for stabilizing the pressure in the vacuum line 67. In addition, since the hole 107 is provided at two positions on the lid member 102b, the risk that the electrolyte leaks or the electrolyte adheres to the hole 107 is greatly reduced.

  As a result, in a large-capacity non-aqueous secondary battery, productivity is improved by increasing the rate of liquid injection. In addition, the quality of the non-aqueous secondary battery is stabilized by stabilizing the degree of vacuum during injection.

  In other words, the liquid injection method and liquid injection facility according to the present embodiment includes an electrode group in which a plurality of positive electrode plates and negative electrode plates are stacked via a separator, and the electrode group is accommodated and filled with an electrolyte. A lithium secondary battery comprising a battery can, an external terminal provided on the battery can, a positive and negative current collecting terminal for electrically connecting the positive and negative electrode plates and the external terminal, and a lid member attached to the battery can. In a lithium secondary battery having a plurality of liquid injection ports provided on the lid member, when performing liquid injection from the liquid injection port, the liquid injection is performed from one liquid injection port and the other liquid injection port. It can be interpreted that when the pressure inside the battery can is reduced from the mouth, the pressure is reduced through a buffer tank for adjusting the pressure inside the battery can. The buffer tank is preferably at least twice the volume of the battery can.

  When liquid is injected from the liquid injection nozzle 68a, the pressure is reduced from the liquid injection nozzle 68b via the pressure adjustment mechanism 81. Thereby, it is possible to lower the pressure that has increased due to the volatilization of the electrolytic solution during the injection, and it is possible to smoothly supply the electrolytic solution to the electrode laminate 103. Furthermore, by passing through the pressure adjusting mechanism 81, excessive pressure reduction inside the battery can 102 is prevented, and volatilization of the electrolyte having a low boiling point is prevented. Thereby, the shift | offset | difference of a composition of electrolyte solution can be prevented and quality stabilization can be aimed at significantly.

  The pressure regulating container 64 is pressure-regulated by a pressure regulating valve 65. Further, even if the pressure inside the battery can 102 is reduced, the battery can can be prevented from suddenly fluctuating in the pressure regulating container 64. It has sufficient volume for 102 volumes.

  Further, in the middle of liquid injection, the nozzle for performing liquid injection is changed from the liquid injection nozzle 68a to the liquid injection nozzle 68b, and the nozzle for exhausting (reducing pressure) is changed from the liquid injection nozzle 68b to the liquid injection nozzle 68a. Thereby, the penetration of the electrolytic solution into the electrode laminate 103 is further improved.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be widely used in non-aqueous secondary batteries and liquid injection methods thereof.

DESCRIPTION OF SYMBOLS 1 Nonaqueous secondary battery 1a Nonaqueous secondary battery 2 Battery can 2a Container-shaped case 2b Cover member 3 Electrode laminated body 4 Current collecting terminal 5 Heat shrink film (film material)
6 External terminal 7 Hole 8 Wiring 11 Non-aqueous secondary battery 21 Non-aqueous secondary battery 61 Injection device 64 Pressure regulating container 65 Pressure regulating valve 66 Vacuum pump 67 Vacuum lines 68a and 68b Injection nozzles (nozzles)
81 Pressure adjusting mechanism 82 Cooling mechanism 83 Drain 91 Depressurization chamber 101 Non-aqueous secondary battery 102 Battery can 102a Container-like case 102b Lid member 103 Electrode laminated body 107 Hole D1 Separation distance D2 of two holes Connecting two holes Dimensions of electrode stack in the direction parallel to the ellipse line

Claims (5)

An electrolyte,
An electrode laminate in which a positive electrode plate and a negative electrode plate are laminated via a separator;
A battery can containing the electrolyte solution and the electrode laminate,
The battery can has a function of an inlet for injecting the electrolyte into the battery can, and a plurality of holes having a function of an exhaust for exhausting the gas inside the battery can When producing a non-aqueous secondary battery equipped with
The electrolytic solution is injected into the battery can from one of the two holes, and the inside of the battery can is exhausted from the other of the two holes to reduce the pressure inside the battery can. A liquid injection device,
A vacuum pump for reducing the pressure;
A nozzle inserted into the other of the two holes and exhausting the gas inside the battery can from the other of the holes;
A vacuum line that is provided between the vacuum pump and the nozzle and is a path for performing pressure reduction by the vacuum pump;
One end is connected to the nozzle side in the vacuum line, the other end is connected to the vacuum pump side in the vacuum line, and a pressure regulating container that suppresses pressure fluctuations in the battery can and in the vacuum line And a pressure adjusting mechanism provided with a liquid injection device.   2. The liquid injection device according to claim 1, wherein the volume of the pressure regulating container is at least twice the volume of the battery can. The pressure adjustment mechanism is
A cooling mechanism for lowering the temperature inside the pressure regulating container by cooling the pressure regulating container;
The liquid injection device according to claim 1, further comprising a drain that discharges the liquid accumulated at the bottom of the pressure regulating container to the outside of the pressure regulating container. An electrolyte,
An electrode laminate in which a positive electrode plate and a negative electrode plate are laminated via a separator;
A battery can containing the electrolyte solution and the electrode laminate,
The battery can has a function of an inlet for injecting the electrolyte into the battery can, and a plurality of holes having a function of an exhaust for exhausting the gas inside the battery can When producing a non-aqueous secondary battery equipped with
The electrolytic solution is injected into the battery can from one of the two holes, and the inside of the battery can is exhausted from the other of the two holes to reduce the pressure inside the battery can. A liquid injection method,
A liquid injection method comprising a pressure adjustment mechanism provided with a pressure adjustment container that suppresses pressure fluctuations in the inside of the battery can and a vacuum line as a path for performing the pressure reduction when the pressure reduction is performed. The electrolyte solution is injected into the inside of the battery can from one of the two holes, the inside of the battery can is exhausted from the other of the two holes, and the inside of the battery can is decompressed. After
The electrolytic solution is injected into the inside of the battery can from the other one of the two holes, and the inside of the battery can is exhausted from one of the two holes to reduce the pressure inside the battery can. The liquid injection method according to claim 4.

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