JP6911347B2 - Liquid injection device and liquid injection method - Google Patents

Description

The present invention relates to a liquid injection device and a liquid injection method.

As a conventional power storage module, a bipolar battery including a bipolar electrode having a positive electrode formed on one surface of an electrode plate and a negative electrode formed on the other surface is known (see Patent Document 1). The bipolar battery includes a laminate formed by laminating a plurality of bipolar electrodes via a separator. The laminated body is provided with an insulating frame for sealing, and the edge portion of the electrode plate is held on the side surface formed by laminating the bipolar electrodes.

Japanese Unexamined Patent Publication No. 2011-151016 Special Table 2016-511919

The method for manufacturing a power storage module as described above includes a step of injecting an electrolytic solution between the bipolar electrodes in the frame. As a method of injecting an electrolytic solution, for example, as shown in Patent Document 2, there is a method of injecting an electrolytic solution into a cell in a vacuum state using a needle or the like. However, since the bipolar electrode is formed of a very thin electrode plate, the volume of the space (cell) sandwiched between the bipolar electrodes is likely to change. If the volume of the cell changes and the volume of the cell differs between the cells, the supply speed of the electrolytic solution from the needle or the like varies, and the production efficiency of the power storage module decreases.

An object of the present invention is to provide a liquid injection device and a liquid injection method capable of increasing the production efficiency of a power storage module.

In the liquid injection device according to the present invention, a laminate consisting of an electrode plate having a positive electrode formed on one side and a negative electrode formed on the other side is laminated via a separator, and the bipolar electrode is laminated. Electrolyzed into a power storage module having a frame that holds the edge of the electrode plate on the side surface of the laminated body to be formed, and a liquid injection port that is provided on the frame and exposes a part of the side surface of the laminated body in the stacking direction. It is a liquid injection device that injects liquid, and can form a vacuum state in a plurality of internal spaces that are spaces between electrode plates adjacent to each other and a restraint jig that restrains the power storage module at a constant pressure or a fixed size in the stacking direction. It has a vacuum pump, a storage unit in which an electrolytic solution is stored, and a plurality of supply pipes that communicate with the storage unit and are inserted into each of a plurality of internal spaces via a liquid injection port, and are in a vacuum state. It is provided with a supply device for injecting an electrolytic solution into the internal space due to the pressure difference between the internal space and the storage unit.

The liquid injection method according to the present invention comprises a laminate in which a bipolar electrode composed of an electrode plate having a positive electrode formed on one surface side and a negative electrode formed on the other surface side is laminated via a separator, and a laminate of bipolar electrodes. To a power storage module having a frame body that holds the edge of the electrode plate on the side surface of the laminated body to be formed, and a liquid injection port that is provided on the frame body and exposes a part of the side surface of the laminated body in the stacking direction. A method of injecting an electrolytic solution, which is a restraining step of restraining a power storage module with a constant pressure or a fixed size in the stacking direction, and a vacuum state formation in which a vacuum state is formed in a plurality of internal spaces which are spaces between electrode plates adjacent to each other. A supply pipe that communicates with the process and the storage section where the electrolyte is stored is inserted into each of the multiple internal spaces via the injection port, and the pressure difference between the vacuum state internal space and the storage section causes the electrolyte to be electrolyzed into the internal space. It has an injection step of injecting a liquid.

In the above-mentioned liquid injection device and liquid injection method, since the power storage module is restrained at a constant pressure or a fixed size in the stacking direction, the displacement of the electrode plate at the time of injecting the electrolytic solution can be suppressed. As a result, the volume of a plurality of internal spaces, which are spaces between the electrode plates adjacent to each other, can be kept constant. As a result, the injection speed when the electrolytic solution is injected into the internal space due to the pressure difference between the internal space in the vacuum state formed by the vacuum pump and the storage portion becomes substantially constant in all the supply pipes. As a result, the time required to inject the specified amount of the electrolytic solution into the internal space is substantially the same for all the supply pipes, and the production efficiency of the power storage module can be improved.

In the liquid injection device and the liquid injection method according to the present invention, the separator may be compressed in the stacking direction.

In the power storage module in which the separator is compressed, the displacement of the electrode plate becomes large due to the stress of the separator, and the volume changes when not restrained by the restraint jig as in the liquid injection device and the liquid injection method according to the present invention. easy. When manufacturing such a power storage module, the production efficiency can be further improved.

In the liquid injection device according to the present invention, a plurality of liquid injection devices are provided for each of the plurality of supply pipes, and each of the storage units may store a preset amount of electrolytic solution.

In the injection step of the liquid injection method according to the present invention, a preset amount of the electrolytic solution may be injected into each of the plurality of internal spaces.

With this liquid injection device and liquid injection method, a specified amount of electrolytic solution can be reliably injected into each of the plurality of internal spaces.

In the liquid injection device according to the present invention, the storage unit may be provided in common to a plurality of supply pipes.

In the injection step of the liquid injection method according to the present invention, the electrolytic solution may be supplied from a common source to a plurality of internal spaces.

In this liquid injection device and liquid injection method, since the volume of all the internal spaces can be maintained constant, the injection speed from the supply pipe becomes constant, and the injection amount of the electrolytic solution can be easily adjusted. Therefore, it is not necessary to provide a portion for storing a preset amount of the electrolytic solution for each of the plurality of supply pipes. As a result, the liquid injection device can be inexpensive and the device configuration can be simplified. Further, also in the case of manufacturing the power storage module, it is possible to save the trouble of storing a preset amount of the electrolytic solution for each of the plurality of supply pipes, and the workability is improved.

In the liquid injection device according to the present invention, the power storage module is provided with a plurality of liquid injection ports, and a plurality of supply pipes in the supply device are provided in each of the plurality of internal spaces via the plurality of liquid injection ports. It may be inserted one by one.

In the liquid injection method according to the present invention, the power storage module is provided with a plurality of the liquid injection ports, and in the injection step, a plurality of supply pipes are provided in a plurality of internal spaces via the plurality of liquid injection ports. May be inserted one by one.

In the laminated body of bipolar electrodes, the distance between the electrode plates adjacent to each other is very narrow, and the distance between the supply pipes must be narrowed. In the liquid injection device and the liquid injection method according to the present invention, for example, when injecting an electrolytic solution into a battery module provided with four liquid injection ports, if one supply pipe is inserted for each of the four internal spaces. This is a good thing, and the distance between adjacent supply pipes can be increased. This makes it easier to arrange each supply pipe when inserting the supply pipe into the internal space.

According to the present invention, the production efficiency of the power storage module can be increased.

It is schematic cross-sectional view which shows the power storage device which comprises the power storage module which the electrolytic solution is injected by the liquid injection device which concerns on one Embodiment. It is schematic cross-sectional view which shows the power storage module which comprises the power storage device of FIG. It is a schematic perspective view which shows the power storage module of FIG. It is an enlarged plan view of a part of the power storage module of FIG. It is schematic cross-sectional view which shows an example of the stacking process of the power storage module of FIG. It is the schematic sectional drawing of the liquid injection apparatus which concerns on one Embodiment. It is the schematic sectional drawing of the liquid injection apparatus which concerns on one Embodiment. It is the schematic sectional drawing of the liquid injection apparatus which concerns on one Embodiment. It is a flowchart which showed an example of the manufacturing method of the power storage module including the liquid injection method which concerns on one Embodiment. It is the schematic sectional drawing of the liquid injection apparatus which concerns on modification 1. FIG. It is the schematic sectional drawing of the liquid injection apparatus which concerns on modification 2. FIG. (A) and (B) are schematic cross-sectional views of the liquid injection device according to the second modification. (A) to (D) are diagrams showing the relationship between the supply pipe of the liquid injection device according to the second modification and the internal space.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate description is omitted. 1 to 13 show an XYZ Cartesian coordinate system except for FIG.

[Configuration of power storage device]
First, the configuration of the power storage module in which the electrolytic solution is injected by the liquid injection device according to the embodiment will be described. The power storage device 10 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage module 12 is, for example, a bipolar battery. Examples of the power storage module 12 include a secondary battery such as a nickel hydrogen secondary battery and a lithium ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery will be illustrated.

The plurality of power storage modules 12 are laminated via a conductor 14 such as a metal plate to form an array 11. The conductor 14 is one metal body arranged between the electricity storage modules 12 and 12 adjacent to each other, and is arranged in contact with both the electricity storage modules 12 and 12 adjacent to each other. The conductor 14 is formed of, for example, a metal material such as aluminum. When the conductor 14 is viewed from the stacking direction (Z direction), the power storage module 12 and the conductor 14 have, for example, a rectangular shape. When viewed from the stacking direction, the conductor 14 is smaller than the power storage module 12, but may be the same as or larger than the power storage module 12. In other words, the conductor 14 is arranged in the region where the power storage module 12 is arranged when viewed from the stacking direction. The conductor 14 is electrically connected to the adjacent power storage module 12. As a result, the plurality of power storage modules 12 are connected in series in the stacking direction.

The conductors 14 are also arranged on the outside of the power storage modules 12 located at both ends in the stacking direction of the power storage modules 12. That is, the conductors 14 are also arranged at both ends of the array 11 in the stacking direction. In the stacking direction, the positive electrode terminal 24 is connected to the conductor 14 located at one end, and the negative electrode terminal 26 is connected to the conductor 14 located at the other end. The positive electrode terminal 24 may be integrated with the conductor 14 to be connected. The negative electrode terminal 26 may be integrated with the conductor 14 to be connected. The positive electrode terminal 24 and the negative electrode terminal 26 extend in a direction (X direction) intersecting the stacking direction. The positive electrode terminal 24 and the negative electrode terminal 26 can be used to charge and discharge the power storage device 10.

The conductor 14 also functions as a heat sink for releasing the heat generated in the power storage module 12. Specifically, the conductor 14 has higher thermal conductivity than the contact surface 12a with the conductor 14 in the power storage module 12. Further, inside the conductor 14, a through hole 14a extending in a direction (Y direction) intersecting the stacking direction is provided. The through hole 14a communicates with the conductor 14 from one side surface facing each other to the other side surface. The through holes 14a are arranged in the stacking direction and the direction intersecting the stacking direction (X direction). By passing a gaseous refrigerant such as air through such a through hole 14a, the heat generated in the power storage module 12 can be efficiently released to the outside. The size of the conductor 14, the material of the conductor 14, the size of the through holes 14a, the number of through holes 14a, and the like are appropriately adjusted so that the temperature of the power storage device 10 does not exceed 50 ° C., for example. The power storage module 12 may be provided with a device for actively circulating (circulating) air through the through hole 14a.

The power storage device 10 may include a restraint member 15 that restrains the alternately stacked power storage modules 12 and the conductor 14 in the stacking direction. The restraint member 15 includes a pair of restraint plates 16 and 17 and a connecting member (bolt 18 and nut 20) for connecting the restraint plates 16 and 17 to each other. An insulating film 22 such as a resin film is arranged between the restraint plates 16 and 17 and the conductor 14. Each of the restraint plates 16 and 17 is made of, for example, a metal such as iron.

When viewed from the stacking direction, the restraint plates 16 and 17 and the insulating film 22 have, for example, a rectangular shape. The insulating film 22 is larger than the conductor 14, and the restraint plates 16 and 17 are larger than the power storage module 12. When viewed from the stacking direction, an insertion hole 16a through which the shaft portion of the bolt 18 is inserted is provided at a position outside the power storage module 12 at the edge portion of the restraint plate 16. Similarly, when viewed from the stacking direction, an insertion hole 17a through which the shaft portion of the bolt 18 is inserted is provided at a position outside the power storage module 12 at the edge portion of the restraint plate 17. When the restraint plates 16 and 17 have a rectangular shape when viewed from the stacking direction, the insertion holes 16a and the insertion holes 17a are located at the corners of the restraint plates 16 and 17.

One restraint plate 16 is abutted against the conductor 14 connected to the negative electrode terminal 26 via the insulating film 22, and the other restraint plate 17 has the insulating film 22 attached to the conductor 14 connected to the positive electrode terminal 24. It is struck through. For example, the bolt 18 is passed through the insertion hole 16a from one restraint plate 16 side toward the other restraint plate 17, and a nut 20 is screwed into the tip of the bolt 18 protruding from the other restraint plate 17. ing. As a result, the insulating film 22, the conductor 14, and the power storage module 12 are sandwiched and unitized, and a restraining load is applied in the stacking direction.

As shown in FIG. 2, the power storage module 12 includes a laminated body 30 in which a plurality of bipolar electrodes 32 are laminated. When viewed from the stacking direction of the bipolar electrodes 32, the laminated body 30 has, for example, a rectangular shape. A separator 40 may be arranged between adjacent bipolar electrodes 32. The bipolar electrode 32 includes an electrode plate 34, a positive electrode layer 36 provided on one surface of the electrode plate 34, and a negative electrode layer 38 provided on the other surface of the electrode plate 34. In the laminated body 30, the positive electrode layer 36 of one bipolar electrode 32 faces the negative electrode layer 38 of one of the bipolar electrodes 32 adjacent to each other in the stacking direction with the separator 40 interposed therebetween, and the negative electrode layer 38 of one bipolar electrode 32 is It faces the positive electrode layer 36 of the other bipolar electrode 32 that is adjacent to each other in the stacking direction with the separator 40 in between.

In the stacking direction, an electrode plate 34 (negative electrode side terminal electrode) having a negative electrode layer 38 arranged on the inner side surface was arranged at one end of the laminated body 30, and a positive electrode layer 36 was arranged on the inner side surface at the other end. The electrode plate 34 (positive electrode side terminal electrode) is arranged. The negative electrode layer 38 of the negative electrode side terminal electrode faces the positive electrode layer 36 of the uppermost bipolar electrode 32 via the separator 40. The positive electrode layer 36 of the positive electrode side terminal electrode faces the negative electrode layer 38 of the lowermost bipolar electrode 32 via the separator 40. The electrode plates 34 of these terminal electrodes are connected to adjacent conductors 14 (see FIG. 1).

The power storage module 12 includes a frame body 50 that holds the edge portion 34a of the electrode plate 34 on the side surface 30a of the laminated body 30 extending in the stacking direction of the bipolar electrodes 32. The frame body 50 is configured to surround the side surface 30a of the laminated body 30. The side surface 50s has, for example, a rectangular shape when viewed from the stacking direction of the bipolar electrodes 32. In this case, the side surface 50s is composed of four rectangular surfaces. The frame body 50 may include a first resin portion 52 that holds the edge portion 34a of the electrode plate 34, and a second resin portion 54 that is provided around the first resin portion 52 when viewed from the stacking direction.

The first resin portion 52 constituting the inner wall of the frame body 50 is provided from one surface of the electrode plate 34 of each bipolar electrode 32 (the surface on which the positive electrode layer 36 is formed) to the end surface of the electrode plate 34 at the edge portion 34a. There is. When viewed from the stacking direction of the bipolar electrodes 32, each first resin portion 52 is provided over the entire circumference of the edge portion 34a of the electrode plate 34 of each bipolar electrode 32. The adjacent first resin portions 52 are welded to each other on a surface extending outside the other surface (the surface on which the negative electrode layer 38 is formed) of the electrode plate 34 of each bipolar electrode 32. As a result, the edge portion 34a of the electrode plate 34 of each bipolar electrode 32 is buried and held in the first resin portion 52. Similar to the edge 34a of the electrode plate 34 of each bipolar electrode 32, the edge 34a of the electrode plate 34 arranged at both ends of the laminated body 30 is also held in a state of being embedded in the first resin portion 52. As a result, an internal space V airtightly partitioned by the electrode plates 34, 34 and the first resin portion 52 is formed between the electrode plates 34, 34 adjacent to each other in the stacking direction. The internal space V contains an electrolytic solution (not shown) composed of an alkaline solution such as an aqueous potassium hydroxide solution.

The second resin portion 54 constituting the outer wall of the frame body 50 is a tubular portion extending over the entire length of the laminated body 30 in the stacking direction of the bipolar electrode 32. The second resin portion 54 covers the outer surface of the first resin portion 52 extending in the stacking direction of the bipolar electrode 32. The second resin portion 54 is welded to the outer surface of the first resin portion 52 on the inner surface extending in the stacking direction of the bipolar electrode 32.

The electrode plate 34 is, for example, a rectangular metal leaf made of nickel. The edge portion 34a of the electrode plate 34 is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated, and the uncoated region is buried in the first resin portion 52 constituting the inner wall of the frame body 50. It is an area that is held. Examples of the positive electrode active material constituting the positive electrode layer 36 include nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode layer 38 include a hydrogen storage alloy. The formation region of the negative electrode layer 38 on the other surface of the electrode plate 34 is slightly larger than the formation region of the positive electrode layer 36 on one surface of the electrode plate 34. The electrode plate 34 may be formed of, for example, a conductive resin such as conductive rubber.

The separator 40 is formed in a sheet shape, for example. Examples of the material forming the separator 40 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like, and a non-woven fabric. Is done. Further, the separator 40 may be reinforced with a vinylidene fluoride resin compound. The separator 40 is not limited to a sheet shape, but may be formed in a bag shape. The separator 40 is compressed in the stacking direction.

The frame body 50 (first resin portion 52 and second resin portion 54) is formed in a rectangular tubular shape by, for example, injection molding using an insulating resin. Examples of the resin material constituting the frame 50 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and the like.

As shown in FIGS. 3 and 4, the frame 50 of the power storage module 12 has side surfaces 50s extending in the stacking direction of the bipolar electrodes 32. The side surface 50s is a surface located on the outer side when viewed from the stacking direction of the bipolar electrodes 32. Therefore, the second resin portion 54 has the side surface 50s of the frame body 50.

A liquid injection port 50a for injecting an electrolytic solution into the frame 50 is provided on the side surface 50s of the frame 50. The liquid injection port 50a is sealed with a sealing material (not shown) after the electrolytic solution is injected. The shape of the liquid injection port 50a is, for example, a rectangle, but may be another shape such as a circle. The liquid injection port 50a extends so that the stacking direction of the bipolar electrodes 32 is the longitudinal direction. The liquid injection port 50a is provided at the center of one side of the rectangular shape of the side surface 50s seen from the stacking direction of the bipolar electrodes 32, but may be arranged offset from the center.

As shown in FIG. 4, the liquid injection port 50a may have a first opening 52a provided in the first resin portion 52 and a second opening 54a provided in the second resin portion 54. The first opening 52a communicates with the internal space V (see FIG. 2) between the adjacent bipolar electrodes 32 and the second opening 54a. The first resin portion 52 is provided with a plurality of first openings 52a, and the second resin portion 54 is provided with a single second opening 54a extending so as to cover the plurality of first openings 52a. There is. In this case, the electrolytic solution is injected into the frame body 50 from the second opening 54a via the first opening 52a. The first opening 52a may be provided in each of the first resin portions 52, or may be provided between adjacent first resin portions 52. The shape of each first opening 52a is, for example, a circle, and the shape of the second opening 54a is, for example, a rectangle.

[Manufacturing method of power storage device]
Next, an example of the manufacturing method of the power storage module 12 shown in FIG. 2 will be described. As shown in FIG. 9, the method of manufacturing the power storage module 12 includes a laminating step S1, a frame body forming step S2, a restraint step S3, and an electrolytic solution injection step (vacuum state forming step / injection step) S4. The process S5 and the like are included. Hereinafter, each step will be described in detail.

(Laminating step S1)
First, as shown in FIG. 5, the bipolar electrodes 32 are laminated via the separator 40 to obtain the laminated body 30. In the present embodiment, the first resin portion 52 is formed on the edge portion 34a of the electrode plate 34 of each bipolar electrode 32 by, for example, injection molding before the laminating step.

(Frame body forming step S2)
Next, the second resin portion 54 is formed by, for example, injection molding (see FIG. 2). The second resin portion 54 is formed by installing a mold M on the peripheral edge of the first resin portion 52 and pouring the resin material of the second resin portion 54 having fluidity into the mold. As a result, as shown in FIGS. 3 and 4, a frame body 50 having the first resin portion 52 and the second resin portion 54 is formed. The mold M has a portion corresponding to a nest for forming the second opening 54a of the liquid injection port 50a.

(Restriction step S3)
Next, the laminated body 30 having the frame body 50 formed in the frame body forming step is restrained in the laminating direction. Hereinafter, for convenience of explanation, the laminated body 30 having the frame body 50 is simply referred to as a power storage module 12. First, the second jig 140 that restrains the power storage module 12 in the stacking direction will be described. As shown in FIGS. 6 and 7, the second jig 140 is a jig that restrains the power storage module 12 with a fixed size (fixed size) in the stacking direction. The second jig 140 includes a pair of restraint plates 141 and 141, bolts 143, and nuts 145. The pair of restraint plates 141 and 141 are members on a flat plate that restrain the power storage module 12 from the stacking direction. The bolt 143 and the nut 145 are members for fastening the pair of restraint plates 141 and 141.

Specifically, a pair of restraint plates 141 and 141 are arranged at both ends of the power storage module 12 in the stacking direction. Next, bolts 143 are inserted into the insertion holes 141a and 141a formed in the pair of restraint plates 141 and 141 from one restraint plate 141 side to the other restraint plate 141. Next, the nut 145 is screwed into the tip of the bolt 143 protruding toward the other restraint plate 141. As a result, the pair of restraint plates 141 and 141 are fastened by the bolts 143 and the nuts 145. At this time, by keeping the tightening amount of the nut 145 constant, the distance between the pair of restraint plates 141 and 141 is maintained, so that the power storage module 12 can be restrained in a fixed size in the stacking direction.

(Electrolytic solution injection step S4)
Next, as shown in FIGS. 6 and 7, the electrolytic solution is injected into the frame body 50 from the liquid injection port 50a provided in the frame body 50. The electrolytic solution is injected in a state where the packing 116 of the attachment 114 is pressed against the peripheral region of the liquid injection port 50a on the side surface 50s of the frame body 50. Next, the configuration of the liquid injection device 100 of one embodiment will be described in detail. The liquid injection device 100 includes a supply device 110, a first jig 120, and a second jig 140. In FIG. 7, the internal structure of the power storage module 12, that is, the configuration of the laminated body 30 as shown in FIG. 2 and the detailed configuration of the supply pipe 112 to be described in detail later are omitted. ..

The supply device 110 includes a dispenser D, a tank (storage unit) T, a valve VA1, a valve VA2, a vacuum gauge G, a vacuum pump P, a supply pipe 112, an attachment 114, an attachment 114, and a packing 116. And have.

The dispenser D is a liquid quantitative discharge device, and accurately quantitatively supplies the electrolytic solution to the tank T. The tank T temporarily stores the electrolytic solution supplied by the dispenser D. The supply path C1 is a pipe for supplying the electrolytic solution from the dispenser D to the power storage module 12. Hereinafter, the dispenser D side will be referred to as the upstream side and the power storage module 12 side will be referred to as the downstream side along the supply path C1. A valve VA1 is arranged in the supply path C1. The valve VA1 regulates the flow rate of the electrolytic solution flowing through the supply path C1. A supply pipe 112 is provided at the downstream end of the supply path C1.

The supply pipe 112 communicates with the supply path C1 and circulates the electrolytic solution supplied from the supply path C1. The supply pipe 112 is a tubular member that penetrates the plate-shaped member 124 provided in the first jig 120, which will be described in detail later, in the plate thickness direction. The attachment 114 is a tubular member fixed to the plate-shaped member 124 and arranged between the plate-shaped member 124 and the side surface 50s of the frame body 50. One end of the supply pipe 112 is located at the liquid injection port 50a. The packing 116 is arranged between the attachment 114 and the side surface 50s of the frame body 50. The packing 116 seals between the supply pipe 112 and the liquid injection port 50a.

As shown in FIG. 8, the supply device 110 of the present embodiment has a plurality of tanks T1 to T8, a plurality of valves VA1 to VA8, and a plurality of supply pipes 112A to 112H. The plurality of tanks T1 to T8, the plurality of valves VA11 to VA18, and the plurality of supply pipes 112A to 112H are connected to one dispenser D via supply paths C11 to C18, respectively. The plurality of supply pipes 112A to 112H are inserted into each of the plurality of internal spaces V1 to V8 via the liquid injection port 50a and the first opening 52a. Note that, in FIG. 8, some configurations shown in FIGS. 6 and 7 are not shown.

Returning to FIGS. 6 and 7, a connection portion C3 to which the pipe C2 is connected is provided between the valve VA1 and the supply pipe 112 in the supply path C1. Hereinafter, the connection portion C3 side will be described as the upstream side and the vacuum pump P side will be described as the downstream side along the pipe C2. A valve VA2 is provided on the downstream side of the connection portion C3 of the pipe C2. The valve VA2 regulates the flow rate of the gas flowing through the pipe C2. A vacuum gauge G is provided on the downstream side of the valve VA2 in the pipe C2. The vacuum gauge G is a pressure gauge for measuring a pressure (negative pressure) below atmospheric pressure. The vacuum pump P is connected to the pipe C2 via a vacuum gauge G. The vacuum pump P is a pump for discharging gas from the internal space V in the power storage module 12 to obtain a vacuum. The other end of the pipe C2 on the downstream side may be connected to the withstand voltage tester of the power storage module 12.

The first jig 120 is a jig that holds the attachment 114 (packing 116) in the supply device 110 in close contact with the frame body 50. The first jig 120 includes a plate-shaped member 122 that supports the side surface of the frame body 50 on the side opposite to the side surface 50s of the power storage module 12, a plate-shaped member 124 that is arranged to face the plate-shaped member 122, and a plate-shaped member. It includes a pair of columnar members 126, 126 that connect the 122 and the plate-shaped member 124. The plate-shaped member 124 has a through hole of the supply pipe 112 and is provided so as to be in contact with the attachment 114. Each columnar member 126 is fixed to the plate-shaped member 122, and is connected to the plate-shaped member 124 by a bolt 128 that penetrates the plate-shaped member 124 in the plate thickness direction. The tip of the bolt 128 is inserted into an insertion hole provided on the upper surface of the columnar member 126 and screwed. By tightening the bolt 128, the packing 116 pressed against the plate-shaped member 124 can be pressed against the side surface 50s of the frame body 50.

The injection of the electrolytic solution is performed using the liquid injection device 100 shown in FIGS. 6 to 8, for example, as follows. First, the vacuum pump P is operated with the valve VA2 opened and the valve VA1 closed. As a result, air is discharged from the internal space V in the frame body 50. Next, the dispenser D is operated to supply a specified amount of the electrolytic solution to the tanks T1 to T8. After that, when the valve VA2 is closed and the valve VA1 is opened, the electrolytic solution stored in the tanks T1 to T8 is injected into the internal space V in the frame body 50.

(Assembly process S5)
After passing through the above steps, the power storage module 12 shown in FIG. 2 is manufactured by sealing the liquid injection port 50a with a sealing material. After that, as shown in FIG. 1, a plurality of power storage modules 12 are laminated via the conductor 14. Positive electrode terminals 24 and negative electrode terminals 26 are connected in advance to the conductors 14 located at both ends in the stacking direction, respectively. After that, a pair of restraint plates 16 and 17 are arranged at both ends in the stacking direction via the insulating film 22. After that, the shaft portion of the bolt 18 is inserted into the insertion hole 16a of the restraint plate 16 and is inserted into the insertion hole 17a of the restraint plate 17. After that, the nut 20 is screwed into the tip of the bolt 18 protruding from the restraint plate 17. In this way, the power storage device 10 shown in FIG. 1 is manufactured.

In the method for manufacturing the liquid injection device 100 and the power storage module 12 of the above-described embodiment, since the power storage module 12 is constrained by a fixed size in the stacking direction, the displacement of the electrode plate 34 at the time of injecting the electrolytic solution can be suppressed. As a result, the volumes of the plurality of internal spaces V1 to V8, which are the spaces between the electrode plates 34, 34 adjacent to each other, as shown in FIG. 8, can be kept constant. As a result, the injection speed at the time of injecting the electrolytic solution into the internal spaces V1 to V8 due to the pressure difference between the internal spaces V1 to V8 in the vacuum state formed by the vacuum pump P and the tanks T1 to T8 is all supplied. It becomes substantially constant in the tubes 112A to 112H. Therefore, the time for injecting the specified amount of the electrolytic solution into the internal spaces V1 to V8 is substantially the same for all the supply pipes 112A to 112H, and the production efficiency of the power storage module 12 can be improved.

The method for manufacturing the liquid injection device 100 and the power storage module 12 of the above-described embodiment is particularly effective when the electrolytic solution is injected into the power storage module 12 in which the separator 40 is compressed in the stacking direction. That is, in such a power storage module 12, the displacement of the electrode plate 34 becomes large due to the stress of the separator 40, so that the storage module 12 is restrained by the second jig 140 as in the manufacturing method of the liquid injection device 100 and the power storage module 12 as described above. If not, the volume is likely to change. Therefore, if this change in volume can be suppressed, the production efficiency of the power storage module 12 can be further improved. As described above, in the method of manufacturing the liquid injection device 100 and the power storage module 12, since the power storage module 12 is constrained in the stacking direction, the displacement of the electrode plate 34 can be suppressed, and the internal spaces V1 to V8 of the power storage module 12 can be suppressed. The volume of the can be kept constant. Therefore, the production efficiency of the power storage module 12 can be further improved.

In the method for manufacturing the liquid injection device 100 and the power storage module 12 of the above-described embodiment, a plurality of tanks T1 to T8 are provided for each of the plurality of supply pipes 112A to 112H, and each of the tanks T1 to T8 is preset. The amount of electrolyte is stored. In the method of manufacturing the liquid injection device 100 and the power storage module 12, a specified amount of electrolytic solution can be reliably injected into each of the plurality of internal spaces V1 to V8.

Although one embodiment has been described in detail above, the present invention is not limited to the above embodiment.

<Modification example 1>
In the above embodiment, as shown in FIG. 8, a plurality of tanks T1 to T8 are provided for each of the plurality of supply pipes 112A to 112H, and each of the tanks T1 to T8 has a preset amount of electrolytic solution. Has been described with reference to an example in which is stored, but the present invention is not limited to this. For example, as in the configuration of the liquid injection device 100A shown in FIG. 10, the tank T may be provided in common to the plurality of supply pipes 112A to 112H. When the electrolytic solution is injected with the power storage module 12 constrained to a fixed size in the stacking direction, the volumes of all the internal spaces V1 to V8 can be kept constant, so that the injection speed from the supply pipes 112A to 112H becomes constant. The injection amount of the electrolytic solution can be easily adjusted. Therefore, it is possible to inject a predetermined amount of the electrolytic solution by adjusting the injection time, for example, without providing a tank for storing a preset amount of the electrolytic solution for each of the plurality of supply pipes 112A to 112H. become. As a result, the liquid injection device can be inexpensive and the device configuration can be simplified. Further, also in the case of manufacturing the power storage module 12, it is possible to save the trouble of storing a preset amount of the electrolytic solution for each of the plurality of supply pipes 112A to 112H, and the workability is improved.

<Modification 2>
In the above embodiment, as shown in FIG. 3, a liquid injection device that injects an electrolytic solution into a laminate 30 (storage module 12) in which one liquid injection port 50a is formed through the liquid injection port 50a. Although the method of manufacturing 100 or the power storage module 12 has been described as an example, the present invention is not limited thereto. For example, for a power storage module provided with a plurality of liquid injection ports 50a, a liquid injection device 100B configured as follows can be used. Hereinafter, a case where the electrolytic solution is injected into the power storage module 330 in which the four injection ports 50a are formed will be taken as an example, and will be described with reference to FIGS. 11 to 13.

As shown in FIG. 11, the liquid injection device 100B is configured so that a supply pipe 112 for injecting an electrolytic solution from the four liquid injection ports 50a can be inserted. That is, the liquid injection device 100B is provided with four attachments 114 provided at positions corresponding to the four liquid injection ports 50a. The electrolytic solution is injected in a state where each of the packings 116 on the attachment 114 is pressed against the peripheral region of each of the injection ports 50a on the side surface 50s of the frame body 50. In this case, the supply pipes 112A to 112H are not inserted into all the internal spaces V1 to V8 (see FIGS. 12A and 12B) at each liquid injection port 50a.

For example, as shown in FIG. 13A, two supply pipes 112A and 112E for inserting into the two internal spaces V1 and V5 are inserted into the first liquid injection port 50a, and two are inserted. As shown in FIG. 13B, two supply pipes 112B and 112F for inserting into the two internal spaces V2 and V6 are inserted into the injection port 50a of the eye, and the third injection port is inserted. Although not shown, two supply pipes 112C and 112G (see FIG. 13C) for insertion into the two internal spaces V3 and V7 are inserted into the port 50a, and a fourth liquid injection port is inserted. Although not shown, the 50a is inserted with two supply pipes 112D and 112H (see FIG. 13D) for insertion into the two internal spaces V4 and V8. As described above, when one supply pipe 112 is inserted into each of the internal spaces V1 to V8, the present modification is characterized in that the supply pipes 112 are dispersed and inserted into the plurality of liquid injection ports 50a.

In the power storage module 330 having a bipolar electrode, the distance between the electrode plates 34, 34 adjacent to each other is very narrow, and the distance between the supply tubes 112, 112 must also be narrow. In the liquid injection device 100B and the liquid injection method according to this modification, for example, when the electrolytic solution is injected into the power storage module 330 provided with the four liquid injection ports 50a, FIGS. 13 (A) to 13 (D) As shown in, it is sufficient to insert the supply pipe 112 for each of the four internal spaces, and it is possible to secure the distances for the three internal spaces. As a result, the distance D1 between the adjacent supply pipes 112 and 112 can be separated. As a result, when the supply pipes 112A to 112H are inserted into the internal spaces V1 to V8, the respective supply pipes 112A to 112H can be easily arranged.

Further, in the above-described embodiment or modified example, when the electrolytic solution is injected into the power storage module, the power storage module is constrained by a fixed size in the stacking direction, but the power storage module is restrained by a constant pressure in the stacking direction. You may.

Further, in the above-described embodiment or modified example, the power storage device 10 has been described with reference to an example of a nickel-metal hydride secondary battery, but a lithium ion secondary battery may also be used. In this case, the positive electrode active material is, for example, a composite oxide, metallic lithium, sulfur or the like. The negative electrode active material is, for example, graphite, highly oriented graphite, mesocarbon microbeads, carbon such as hard carbon and soft carbon, alkali metals such as lithium and sodium, metal compounds, SiOx (0.5 ≦ x ≦ 1.5). Such as metal oxides, carbon with added boron, and the like. As the electrode plate, stainless steel foil or the like can be used.

10 ... power storage device, 12 ... power storage module, 30 ... laminate, 32 ... bipolar electrode, 34 ... electrode plate, 36 ... positive electrode layer, 38 ... negative electrode layer, 40 ... separator, 50 ... frame, 50a ... liquid injection port, 100, 100A, 100B ... Liquid injection device, 110 ... Supply device, 112 (112A to 112H) ... Supply pipe, 120 ... First jig, 140 ... Second jig, 141 ... Restraint plate, 143 ... Bolt, 145 ... Nut, 330 ... Power storage module, C1 (C11 to C18) ... Supply path, C2 ... Piping, C3 ... Connection, P ... Vacuum pump, T (T1 to T8) ... Tank (storage), V (V1 to V8) … Internal space.

Claims (8)

A laminated body in which bipolar electrodes composed of electrode plates having a positive electrode formed on one surface side and a negative electrode formed on the other surface side are laminated via a separator, and a side surface of the laminated body formed by laminating the bipolar electrodes. A frame body that holds the edge of the electrode plate, and a liquid injection port that is provided in the frame body and has a plurality of openings that communicate with each of a plurality of internal spaces that are spaces between the electrode plates that are adjacent to each other. A liquid injection device that injects an electrolytic solution into a power storage module having a
A restraint jig that restrains the power storage module at a constant pressure or a fixed size in the stacking direction,
A vacuum pump capable of forming a vacuum to each of the plurality of internal space,
The storage unit in which the electrolytic solution is stored, a plurality of supply pipes communicating with the storage unit and communicating with the vacuum pump via a pipe, and the plurality of supply pipes are held and the liquid injection in the frame body. An attachment having a packing that is in close contact with the periphery of the mouth, and a treatment that holds the attachment so that the packing is pressed against the frame and the plurality of supply pipes supply the electrolytic solution to each of the plurality of openings. A liquid injection device comprising a tool and a supply device for injecting the electrolytic solution into the internal space by a pressure difference between the internal space in a vacuum state and the storage portion. The liquid injection device according to claim 1, wherein the separator in the power storage module is compressed in the stacking direction. The liquid injection device according to claim 1 or 2, wherein a plurality of the storage units are provided for each of the plurality of supply pipes, and each of the storage units stores a preset amount of the electrolytic solution. The liquid injection device according to claim 1 or 2, wherein the storage unit is provided in common with a plurality of the supply pipes. A laminated body in which bipolar electrodes composed of electrode plates having a positive electrode formed on one surface side and a negative electrode formed on the other surface side are laminated via a separator, and a side surface of the laminated body formed by laminating the bipolar electrodes. A frame body that holds the edge of the electrode plate, and a liquid injection port that is provided in the frame body and has a plurality of openings that communicate with each of a plurality of internal spaces that are spaces between the electrode plates that are adjacent to each other. It is a method of injecting an electrolytic solution into a power storage module having a.
A restraining step of restraining the power storage module at a constant pressure or a fixed size in the stacking direction,
A vacuum forming process for forming a vacuum in each of said plurality of internal space,
An attachment having a packing that communicates with a storage portion in which the electrolytic solution is stored, holds a plurality of supply pipes that communicate with a vacuum pump via a pipe, and adheres to the periphery of the liquid injection port in the frame. The packing is pressed against the frame and the plurality of supply pipes are held by a jig so that the electrolytic solution can be supplied to each of the plurality of openings, and the internal space in a vacuum state and the storage portion are held. A liquid injection method comprising an injection step of injecting the electrolytic solution into the internal space by the pressure difference of the above. The liquid injection method according to claim 5 , wherein the separator in the power storage module is compressed in the stacking direction. The liquid injection method according to claim 5 or 6 , wherein in the injection step, a preset amount of the electrolytic solution is injected into each of the plurality of internal spaces. The liquid injection method according to claim 5 or 6 , wherein in the injection step, the electrolytic solution is supplied from a common source to the plurality of internal spaces.

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