JP6956029B2 - How to manufacture film exterior batteries - Google Patents

Description

The present invention relates to a method for manufacturing a film exterior battery.

The film exterior battery is configured by accommodating a power generation element together with an electrolytic solution inside an exterior body made of a flexible film. In the power generation element, a positive electrode and a negative electrode are laminated via a separator. The film is, for example, an aluminum laminated film in which a resin film is laminated on both sides of a metal layer. The portion where the films are overlapped is sealed by joining the resin films to each other by heat fusion after filling with the electrolytic solution.

In the process of charging among various steps of manufacturing a battery, it is necessary to pressurize the battery under an appropriate pressing force at the time of charging. This is because if bubbles are present in the planes of the electrodes of the positive electrode and the negative electrode, the electrochemical reaction during charging may occur non-uniformly in the electrode planes.

A pressurizing device, also called a pressurizing magazine, is used to charge the film exterior battery while pressurizing it (see Patent Document 1). The pressurizing device has a movable plate that pressurizes the film exterior battery. The movable plate moves toward the film exterior battery as the drive rod rotates, and pressurizes the film exterior battery. The drive rod is rotationally driven by an electric tool such as a nut runner.

The electrodes of the film exterior battery expand as it is charged. When the drive rod is tightened with a relatively high torque, the pushing force (axial force) from the movable plate and the force due to the expansion of the battery act on the pressurizing device. If this force exceeds the load capacity of the pressurizing device, the pressurizing device may be damaged or the battery itself may be damaged. Therefore, when pressurizing the film exterior battery, the drive rod is tightened with a relatively low torque.

On the other hand, since the drive rod is tightened with a relatively low torque, galling is likely to occur due to the sliding resistance of the movable plate itself. If galling occurs on the movable plate, poor pressurization of the battery may occur, resulting in variations in the performance of the manufactured battery. In order to properly control the pushing amount of the movable plate, it is necessary to monitor and manage the torque when tightening the drive rod.

As a general technique for detecting whether or not a bolt is fastened, there is known a technique for monitoring the torque at the time of bolt tightening and determining whether or not the bolt is galled by the presence or absence of a sudden rise in torque. (See Patent Document 2.)

JP-A-2015-37047 Japanese Unexamined Patent Publication No. 6-99322

In the case of the above-mentioned pressurizing device, unlike the case of fastening bolts, torque is generated by transmitting the axial force due to fastening of the drive rod to the battery via the movable plate. When pressurizing the film exterior battery, the pressurization status until the pressing of the electrolytic solution existing between the power generation element and the exterior body is completed, and the subsequent pressurization until the pressing of the power generation element is completed. There is a big difference from the situation. Pushing in the electrolytic solution pressurizes a relatively soft object, whereas pushing in a power generation element on which electrodes are laminated pressurizes a relatively hard object. When the electrolytic solution is pushed in, the torque rises relatively slowly, while when the power generation element is pushed in, the torque rises relatively sharply. Therefore, it is not possible to make a determination that matches the pressurization state of the film exterior battery only based on the presence or absence of a sudden rise in torque.

Therefore, an object of the present invention is to provide a method for manufacturing a film exterior battery, which can accurately detect a pressurization failure of the film exterior battery at the time of manufacturing the film exterior battery.

In the present invention for achieving the above object, a flat film in which a positive electrode and a negative electrode are laminated via a separator and a power generation element is housed together with an electrolytic solution in an exterior body made of a flexible film. This is a method of manufacturing an exterior battery. In the method for manufacturing a film exterior battery, the film exterior battery is sandwiched between paired plate members that can move relatively close to each other, and the paired plate members are relatively close to each other as the drive rod rotates. Pressurize the film exterior battery. At this time, the torque generated in the drive rod is detected. Arbitrary torque (Ta) when determining whether or not pressurization failure of the film exterior battery has occurred in the section between the arbitrary torque (Ta) and the determination torque (Tb) (however, Ta <Tb). The amount of change in torque (ΔT) with respect to the angle difference (Δθ) between the amount of rotation (θa) of the drive rod when reaching Is,
α = ΔT / Δθ = (Tb-Ta) / (θb-θa)
Is the judgment value. Then, by comparing the determination value (α) with a predetermined threshold value (αs), the film exterior battery is subjected to a section between the arbitrary torque (Ta) and the determination torque (Tb). Determine if pressurization failure has occurred.

According to the present invention, a film exterior battery can be manufactured by accurately detecting a pressurization failure of the film exterior battery.

It is a perspective view which shows the film exterior battery. It is sectional drawing which follows line 2-2 of FIG. It is a figure which shows a part of the manufacturing process of a film exterior battery. It is a figure which shows the state of the battery storage transport process and the pressurization process schematically. It is a perspective view which shows the pressurizing apparatus. It is sectional drawing which shows the part of a pressurizing apparatus in an enlarged manner. It is explanatory drawing explaining the management of the pressurization state of a film exterior battery. It is explanatory drawing explaining the management of the pressurization state of a film exterior battery. It is a flowchart which shows the procedure of management of the pressurization state of a film exterior battery. It is a graph which shows typically the torque-angle curve when the film exterior battery in an embodiment is pressurized.

Hereinafter, embodiments will be described with reference to the attached drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. The size and ratio of each member in the drawing may be exaggerated for convenience of explanation and may differ from the actual size and ratio.

(Film exterior battery 10)
First, the film exterior battery 10 to be manufactured will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the film exterior battery 10, and FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG.

The illustrated film exterior battery 10 is a laminated flat battery, and is electrically connected to the power generation element 20, the exterior body 56 accommodating the power generation element 20, and the power generation element 20 and led out to the outside of the exterior body 56. It has a positive electrode tab 33 and a negative electrode tab 43. The exterior body 56 is made of a flexible film 50. The film 50 has a laminated structure in which resin films 52 and 53 are formed on both sides of the metal layer 51. A bag-shaped container is formed by the film 50, and the power generation element 20 is housed in this container. The sealing portion 54 on which the films 50 are overlapped is sealed by joining the resin films 52 and 52 to each other by heat fusion. The film 50 is electrically insulated by coating the entire surfaces of both sides of the metal layer 51 with the resin films 52 and 53.

The power generation element 20 includes a positive electrode 30 having a positive electrode active material layer 32 arranged on the surface of the positive electrode current collector 31 and a negative electrode 40 having a negative electrode active material layer 42 arranged on the surface of the negative electrode current collector 41. Has a separator 60 that holds the electrolyte. The cell cell layer 21 is formed by facing the positive electrode active material layer 32 and the negative electrode active material layer 42 with the separator 60 interposed therebetween. The power generation element 20 is housed together with the electrolytic solution inside the exterior body 56 in a state where a plurality of cell cell layers 21 are laminated. The positive electrode tab 33 is electrically connected to the positive electrode 30, and the negative electrode tab 43 is electrically connected to the negative electrode 40. In the following description, the positive electrode 30 and the negative electrode 40 are collectively referred to as electrodes 30 and 40.

In the power generation element 20 shown in FIG. 2, the outermost layer electrode located in the outermost layer is the negative electrode 40. In the negative electrode 40 of the outermost layer, the negative electrode active material layer 42 is arranged only on one surface of the negative electrode current collector 41. The negative electrode 40 of the outermost layer may be one in which the negative electrode active material layer 42 is arranged on both surfaces of the negative electrode current collector 41. The outermost layer electrode may be a positive electrode 30.

The exterior body 56 accommodates the power generation element 20 together with the electrolytic solution. The exterior body 56 is composed of a laminated sheet having a three-layer structure. The innermost first layer resin film 52 is formed using a heat-sealing resin such as polypropylene (PP), polyethylene (PE), ionomer, or ethylene vinyl acetate (EVA). The second metal layer 51 is formed by using a foil-like metal such as Al foil or Ni foil. The third layer resin film 53 is formed by using, for example, rigid polyethylene terephthalate (PET) or nylon. The exterior body 56 has a sealing portion 54 in which peripheral edge portions 55 are overlapped and joined to each other. The sealing portion 54 is formed by welding the heat-weldable resin of the first layer resin film 52.

The manufacturing procedure of the film exterior battery 10 is as follows. First, the positive electrode 30, the separator 60, and the negative electrode 40 are sequentially laminated. The positive electrode tab 33 is connected to the positive electrode 30 and the negative electrode tab 43 is connected to the negative electrode 40 by spot welding or the like. As a result, the power generation element 20 is formed. Next, the power generation element 20 is covered with the exterior body 56, and the peripheral edges 55 of the exterior body 56 are heat-sealed to each other, leaving a relatively small filling port. Next, the electrolytic solution is filled inside the exterior body 56 through the filling port, and then the filling port is heat-sealed to seal the exterior body 56. Next, the film exterior battery 10 is initially charged and aged for a certain period of time. Then, after the aging is completed, voltage inspection, recharging, etc. are performed.

FIG. 3 shows a part of the manufacturing process of the film exterior battery 10.

After the electrolytic solution injection step S1, in the battery storage and transport step S2, the plurality of film exterior batteries 10 are housed in the pressurizing device 100 (see FIG. 4) and transported to a predetermined pressurizing stage 101 (see FIG. 4). Then, in the pressurizing step S3, the film exterior battery 10 is pressurized by the pressurizing device 100. During the pressurizing step S3, the film exterior battery 10 is charged. Then, in the screening step S4, it is inspected whether or not there is a conductive foreign substance inside the film exterior battery 10. The pressurizing step S3 and the screening step S4 are carried out at an appropriate timing after the filling of the electrolytic solution and the sealing of the film 50 (sealing of the filling port) in the above-mentioned manufacturing steps.

(Pressurizing step S3 and pressurizing device 100)
The pressurizing step S3 and the pressurizing device 100 will be described with reference to FIGS. 4 to 6. FIG. 4 is a diagram schematically showing the state of the battery storage / transporting step S2 and the pressurizing step S3. FIG. 5 is a perspective view showing the pressurizing device 100, and FIG. 6 is an enlarged cross-sectional view showing a part of the pressurizing device 100.

As shown in FIG. 4, in the pressurizing step S3, the pressurizing device 100 is conveyed to the pressurizing stage 101 by a roller conveyor 102 or the like. A large number of film exterior batteries 10 are housed in the pressurizing device 100. A nut runner 103 is provided on the pressurizing stage 101. The film exterior battery 10 is pressurized by the rotational drive of the nut runner 103. After the pressurization is completed, the pressurizing device 100 is again conveyed by the roller conveyor 102 to the stage where the next screening step S4 is performed.

As shown in FIGS. 5 and 6, the pressurizing device 100 generally has a pair of movable plates 111 (corresponding to plate members) that are relatively movable in close proximity to each other. The film exterior battery 10 is sandwiched by a pair of movable plates 111. Then, the film exterior battery 10 is pressurized by bringing the pair of movable plates 111 relatively close to each other as the drive rod 114 rotates.

More specifically, the pressurizing device 100 has a housing 110 having a substantially box shape and a plurality of movable plates 111 having a rectangular plate shape. The housing 110 has a front wall 110a, a rear wall 110b, and a bottom wall 110c connecting the front wall 110a and the rear wall 110b. The movable plate 111 is movably housed in the housing 110. The lower end of the movable plate 111 has a bottom wall portion 111b bent in an L-shaped cross section. The bottom wall portion 111b supports the lower end of the film exterior battery 10. The film exterior battery 10 is sandwiched by a pair of adjacent movable plates 111. The number of film exterior batteries 10 and movable plates 111 is not limited to the number shown in FIG. 5, and can be changed as appropriate.

The pressurizing device 100 further has a sliding mechanism that slideably holds the movable plate 111 along the pressurizing direction (horizontal direction) F. The pressurizing direction F is the same as the stacking direction of the electrodes 30 and 40 in the power generation element 20. The slide mechanism holds the movable plate 111 so that the movable plate 111 does not come into contact with the bottom wall 110c of the housing 110. The slide mechanism has guide holes 111a provided at the four corners of the movable plate 111, and a guide rod 112 inserted into the guide holes 111a. Both ends of the guide rod 112 are fixed to the front wall 110a and the rear wall 110b of the housing 110.

The pressurizing device 100 has a pressing plate 113 arranged between the front wall 110a of the housing 110 and the movable plate 111. The pressing plate 113 has a slightly larger area than the movable plate 111, and has a thicker wall thickness than the movable plate 111. The pressing plate 113 is also slidably held along the pressurizing direction (horizontal direction) F through which the guide rod 112 is inserted. The tip of the drive rod 114 having a male screw 115 cut on the outer circumference is in contact with the pressing plate 113. A screw hole 110d is formed through the front wall 110a of the housing 110. On the inner peripheral surface of the screw hole 110d, a female screw that meshes with the male screw 115 on the outer circumference of the drive rod 114 is formed.

In the pressurizing step S3, first, the film exterior battery 10 is sandwiched between two adjacent movable plates 111. Next, the nut runner 103 rotates the drive rod 114 in the clockwise direction. The tip of the drive rod 114 moves toward the rear wall 110b of the housing 110. As the drive rod 114 moves, the pressing plate 113 is pushed in the pressurizing direction F. As a result, each film exterior battery 10 is sandwiched between two adjacent movable plates 111 and is pressurized in the pressurizing direction F. Uniform surface pressure acts on the power generation element 20 from both sides along the stacking direction of the electrodes 30 and 40.

The operation, stoppage, rotation speed, and the like of the nut runner 103 are controlled by the control unit 104 provided on the pressurizing stage 101 (see FIG. 3). The control unit 104 is mainly composed of a CPU, a memory, an input / output unit, and the like. The nut runner 103 includes a torque sensor 105 that detects torque acting on the rotation shaft of the nut runner 103, and an encoder 106 that detects the amount of rotation of the rotation shaft of the nut runner 103. The control unit 104 inputs the torque measured by the torque sensor 105 and the rotation amount of the nut runner 103 measured by the encoder 106. The amount of rotation of the nut runner 103 is equal to the amount of rotation of the drive rod 114. The control unit 104 manages the pressurized state of the film exterior battery 10 based on the torque measured by the torque sensor 105 and the amount of rotation of the drive rod 114.

(Management of pressurized state of film exterior battery 10)
The management of the pressurized state of the film exterior battery 10 will be described with reference to FIGS. 7A and 7B. 7A and 7B are explanatory views for explaining the management of the pressurized state of the film exterior battery 10. Each figure is a graph schematically showing a torque-angle curve when the film exterior battery 10 is pressurized. The horizontal axis of these graphs represents the amount of rotation of the drive rod 114 by the rotation angle (degrees), and the vertical axis represents the torque acting on the drive rod 114. The amount of rotation of the drive rod 114 is the amount of rotation after the drive rod 114 starts rotating.

When the film exterior battery 10 is carried into the pressurizing device 100, between the film exterior batteries 10 and between the movable plates 111, between the pressing plate 113 and the movable plate 111, and between the rear wall 110b and the movable plate 111. There is a gap between them. Therefore, even when the rotation of the drive rod 114 is started, the torque remains relatively low until the film exterior batteries 10 come into contact with each other to such an extent that the above-mentioned gap is almost eliminated. The rotation amount θ0 represents the rotation amount of the drive rod 114 at the time when the film exterior batteries 10 are substantially in contact with each other.

In the manufacture of the film exterior battery 10, for example, it is detected whether or not a pressurization failure of the film exterior battery 10 has occurred before or during charging of the film exterior battery 10. In the film exterior battery 10, the electrodes 30 and 40 expand as the battery is charged. When pressurizing the film exterior battery 10 in order to prevent the pressurizing device 100 from being damaged or the battery 10 itself from being damaged, it is necessary to tighten the drive rod 114 with a relatively low torque. On the other hand, when the drive rod 114 is tightened with a relatively low torque, galling is likely to occur due to the sliding resistance of the movable plate 111 itself (sliding resistance between the guide hole 111a and the guide rod 112). If galling occurs on the movable plate 111, poor pressurization of the battery 10 may occur, which may lead to variations in the performance of the manufactured battery 10. In order to properly control the pushing amount of the movable plate 111, it is necessary to monitor and manage the torque when the drive rod 114 is tightened.

First, the film exterior battery 10 is sandwiched by a pair of movable plates 111 that are relatively movable in close proximity to each other. The film exterior battery 10 is pressurized by bringing the pair of movable plates 111 relatively close to each other as the drive rod 114 rotates. At this time, the torque generated in the drive rod 114 is detected.

In the section between the arbitrary torque Ta and the determination torque Tb (however, Ta <Tb), it is determined as follows whether or not the pressurization failure of the film exterior battery 10 has occurred.

The angle difference Δθ between the rotation amount θa of the drive rod 114 when the arbitrary torque Ta is reached and the rotation amount θb of the drive rod 114 when the determination torque Tb is reached is detected. The amount of change in torque ΔT with respect to this angle difference Δθ,
α = ΔT / Δθ = Tb-Ta / θb-θa
Is the judgment value. The determination value α is the slope of the torque-angle curve.

Then, by comparing the determination value α with the predetermined threshold value αs, it is determined whether or not the pressurization failure of the film exterior battery 10 has occurred in the section between the determination torque Ta and the arbitrary torque Tb. ..

Since the drive rod 114 is screwed into the front wall 110a of the housing 110 via a screw portion (male screw 115, female screw), the movement dimension when the drive rod 114 makes one rotation is known. Further, various dimensions and volumes of the film exterior battery 10 and the filling amount of the electrolytic solution are also known as design data. By considering these data, the safety factor, and the like, it is possible to set the threshold value αs at which it can be determined that the pressurization of the film exterior battery 10 has been normally performed.

FIG. 7A schematically shows the threshold value αs.

Regarding the torque change curve (1) shown by the solid line in FIG. 7A, the determination value α is smaller than the threshold value αs, and the torque increases with a relatively gentle slope. In this case, it is determined that the pressurization of the film exterior battery 10 has been normally performed.

Regarding the torque change curve (2) shown by the alternate long and short dash line in FIG. 7A, the determination value α is larger than the threshold value αs, and the torque increases at a large slope. In this case, it is determined that the film exterior battery 10 has a poor pressurization.

Regarding the torque change curve (3) shown by the alternate long and short dash line in FIG. 7A, the determination value α is larger than the threshold value αs, and it is determined that the film exterior battery 10 has a poor pressurization. In the case of the torque change curve (3), the torque rapidly increases before the rotation amount becomes θ0 (when the film exterior batteries 10 are in a state of being substantially in contact with each other). From this, it can be estimated that in the case of the torque change curve (3), a large galling occurs in the movable plate 111 and the pressing plate 113 as compared with the case of the torque change curve (2).

In the above example, when the determination value α is larger than the threshold value αs, it is determined that the pressurization failure of the film exterior battery 10 has occurred. However, the determination of poor pressurization is not limited to the case where the determination value α is larger than the threshold value αs.

FIG. 7B shows an example in which it is determined that a pressurization failure of the film exterior battery 10 has occurred when the determination value α is smaller than the threshold value αs.

FIG. 7B schematically shows the threshold value αs.

Regarding the torque change curve (4) shown by the solid line in FIG. 7B, the determination value α is larger than the threshold value αs, and the torque increases at a relatively large slope. In this case, it is determined that the pressurization of the film exterior battery 10 has been normally performed.

Regarding the torque change curve (5) indicated by the alternate long and short dash line, the determination value α is smaller than the threshold value αs, and the torque increases at a small slope. In this case, it is determined that the film exterior battery 10 has a poor pressurization.

When the film exterior battery 10 is pressurized, the pressurization state until the pressing of the electrolytic solution existing between the power generation element 20 and the exterior body 56 is completed, and the subsequent pressing of the power generation element 20 are completed. There is a big difference from the pressurization situation up to. Pushing in the electrolytic solution pressurizes a relatively soft object, whereas pushing in the power generation element 20 on which the electrodes are laminated pressurizes a relatively hard object. As described above, by comparing the determination value α indicating the slope of the torque change curve with the predetermined threshold value αs, the film exterior battery 10 is added in the section between the arbitrary torque Ta and the determination torque Tb. Determine if pressure failure has occurred. Therefore, it is possible to accurately determine the pressurization failure of the film exterior battery 10 by setting the threshold value αs that matches the pressurization state of the film exterior battery 10.

(Management of Pressurized State of Film Exterior Battery 10 in the Embodiment)
The management of the pressurized state of the film exterior battery 10 in the embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a procedure for managing the pressurized state of the film exterior battery 10, and FIG. 9 is a graph schematically showing a torque-angle curve when the film exterior battery 10 in the embodiment is pressurized. It corresponds to the graphs shown in FIGS. 7A and 7B.

As described above, when the film exterior battery 10 is pressurized, the pressurization state until the pushing of the electrolytic solution existing between the power generation element 20 and the exterior body 56 is completed, and the subsequent power generation element 20 is performed thereafter. There is a big difference from the pressurization condition until the pushing is completed. Therefore, in the present embodiment, the poor pressurization of the film exterior battery 10 is determined by a determination method that matches the pressurization status of each section. The flowchart of FIG. 8 is roughly divided into a determination in the section where the electrolytic solution is pushed in (steps S12 to S15) and a determination in the section where the power generation element 20 is pushed in (steps S16 to S19).

In FIG. 9, the rotation amount θ1 indicates the rotation amount of the drive rod 114 when the first torque T1 is reached. The rotation amount θ2 indicates the rotation amount of the drive rod 114 when the second torque T2 (however, T1 <T2) is reached. The rotation amount θ3 indicates the rotation amount of the drive rod 114 when the third torque T3 (however, T2 <T3) is reached. The second torque T2 is a torque that generates a pressing force that terminates the pushing of the electrolytic solution existing between the power generation element 20 and the exterior body 56. The third torque T3 is a torque that generates a pressing force at which the pushing of the power generation element 20 is completed.

The detection of whether or not the pressurization failure of the film exterior battery 10 has occurred is performed before or during charging of the film exterior battery 10.

As shown in FIG. 8, when the nut runner 103 starts operating to pressurize the film exterior battery 10 (step S11), the control unit 104 determines the torque measured by the torque sensor 105 and the amount of rotation of the drive rod 114. take in.

In the section where the electrolytic solution is pushed in, the arbitrary torque Ta in the explanation of the principle is the first torque T1, and the determination torque Tb is the end of pushing the electrolytic solution existing between the power generation element 20 and the exterior body 56. This is the second torque T2 that causes the pressing force to be applied.

The control unit 104 detects the angle difference Δθ between the rotation amount θ1 of the drive rod 114 when the first torque T1 is reached and the rotation amount θ2 of the drive rod 114 when the second torque T2 is reached. The amount of change in torque ΔT with respect to this angle difference Δθ,
Judgment value α1 = ΔT / Δθ = (T2-T1) / (θ2-θ1)
(Step S12). The determination value α1 is the slope of the torque-angle curve.

The control unit 104 compares the determination value α1 with the predetermined first threshold value αs1 (step S13). Here, the moving dimensions when the drive rod 114 makes one rotation are known, and various dimensions and volumes of the film exterior battery 10 and the filling amount of the electrolytic solution are also known as design data. By considering these data, the safety factor, and the like, it is possible to set a first threshold value αs1 that can determine that the electrolytic solution has been pushed in normally.

Regarding the torque change curve shown by the solid line in FIG. 9, the determination value α1 increases at a slope equal to or higher than the first threshold value αs1.

When the determination value α1 is equal to or greater than the first threshold value αs1 (step S13 “YES”), the electrolytic solution existing between the power generation element 20 and the film 50 is normally pushed into the film exterior battery 10. It is determined that the pressurization has been performed normally (step S14).

On the other hand, when the determination value α1 is smaller than the first threshold value αs1 (step S13 “NO”), the electrolytic solution existing between the power generation element 20 and the film 50 is poorly pushed, and the film exterior It is determined that the pressurization failure of the battery 10 has occurred (step S15). As a situation where the electrolytic solution is poorly pushed in, there is a case where the electrolytic solution leaks due to a poor sealing of the film 50. In this case, the pressurization process of the film exterior battery 10 is stopped (step S20).

In the pushing section of the power generation element 20, any torque Ta in the description of the principle is a second torque T2 that causes a pressing force to end the pushing of the electrolytic solution existing between the power generation element 20 and the exterior body 56. Yes, the determination torque Tb is a third torque T3 that generates a pressing force at which the pushing of the power generation element 20 ends.

The control unit 104 detects the angle difference Δθ between the rotation amount θ2 of the drive rod 114 when the second torque T2 is reached and the rotation amount θ3 of the drive rod 114 when the third torque T3 is reached. The amount of change in torque ΔT with respect to this angle difference Δθ,
Judgment value α2 = ΔT / Δθ = (T3-T2) / (θ3-θ2)
(Step S16). The determination value α2 is the slope of the torque-angle curve.

The control unit 104 compares the determination value α2 with the predetermined second threshold value αs2 (step S17). Here, the moving dimensions when the drive rod 114 makes one rotation are known, and various dimensions and volumes of the film exterior battery 10 and the filling amount of the electrolytic solution are also known as design data. By considering these data, the safety factor, and the like, it is possible to set a second threshold value αs2 at which it can be determined that the power generation element 20 has been pushed in normally.

Regarding the torque change curve shown by the solid line in FIG. 9, the determination value α2 increases at a slope equal to or less than the second threshold value αs2.

When the determination value α2 is equal to or less than the second threshold value αs2 (step S17 “YES”), it is determined that the power generation element 20 has been pushed in normally and the film exterior battery 10 has been normally pressurized (step S17 “YES”). Step S18).

On the other hand, when the determination value α2 is larger than the second threshold value αs2 (step S17 “NO”), galling that hinders the movement of the movable plate 111 occurs, the power generation element 20 is poorly pushed in, and the film exterior It is determined that the pressurization failure of the battery 10 has occurred (step S19). In this case, the pressurization process of the film exterior battery 10 is stopped (step S20).

As described above, when the film exterior battery 10 is pressurized, there is a large gap between the pressurization state of the section where the electrolytic solution is pushed in and the subsequent pressurization state of the section where the power generation element 20 is pushed. There is a difference. Therefore, in the present embodiment, a determination method that matches the pressurization situation is adopted.

In the section where the electrolytic solution is pushed in, the arbitrary torque Ta in the explanation of the principle is the first torque T1, and the determination torque Tb ends the pushing of the electrolytic solution existing between the power generation element 20 and the exterior body 56. The second torque T2 (however, T1 <T2) that causes the pressing force to be applied. The determination value α is the torque change amount ΔT with respect to the angle difference Δθ between the rotation amount θ1 of the drive rod 114 when the first torque T1 is reached and the rotation amount θ2 of the drive rod 114 when the second torque T2 is reached. Α1 = ΔT / Δθ = (T2-T1) / (θ2-θ1). Then, when the determination value α1 is smaller than the predetermined first threshold value αs1, the pushing of the electrolytic solution existing between the power generation element 20 and the film 50 is defective, and the film exterior battery 10 is added. It is determined that poor pressure has occurred.

With this configuration, the first threshold value αs1 that matches the pressurizing condition in the section where the electrolytic solution is pushed is set, the pushing of the electrolytic solution is poor, and the pressurization of the film exterior battery 10 is poor. Can be accurately determined.

In the pushing section of the power generation element 20, any torque Ta in the explanation of the principle is a second torque T2 that generates a pressing force for ending the pushing of the electrolytic solution existing between the power generation element 20 and the exterior body 56. Yes, the determination torque Tb is the third torque T3 (however, T2 <T3) that generates a pressing force at which the pushing of the power generation element 20 ends. The determination value α is the torque change amount ΔT with respect to the angle difference Δθ between the rotation amount θ2 of the drive rod 114 when the second torque T2 is reached and the rotation amount θ3 of the drive rod 114 when the third torque T3 is reached. Α2 = ΔT / Δθ = (T3-T2) / (θ3-θ2). Then, when the determination value α2 is larger than the predetermined second threshold value αs2, it is determined that galling that hinders the movement of the movable plate 111 has occurred and the pressurization failure of the film exterior battery 10 has occurred.

With this configuration, a second threshold value αs2 that matches the pressurization condition in the pushing section of the power generation element 20 is set, and galling that hinders the movement of the movable plate 111 occurs, and the film exterior battery 10 It is possible to accurately determine that a pressurization failure has occurred.

Further, it is preferable to detect whether or not the pressurization failure of the film exterior battery 10 has occurred before or during charging of the film exterior battery 10.

When charging the film exterior battery 10, the drive rod 114 must be tightened with a relatively low torque in order to prevent damage to the pressurizing device 100 and damage to the battery itself, and poor pressurization of the battery is likely to occur. .. By applying the method for manufacturing the film exterior battery 10 of the present embodiment, it is possible to accurately determine that a pressurization failure of the film exterior battery 10 has occurred before or during charging, and an appropriate measure (sliding of the movable plate 111). It is possible to adjust the mobility, etc.).

Further, it is preferable to detect whether or not a pressurization failure has occurred in a group including a plurality of film exterior batteries 10 as in the pressurizing device 100 of the illustrated example.

This is because the productivity of the film exterior battery 10 is improved. However, it goes without saying that the manufacturing method of the film exterior battery 10 of the present invention can be applied even in the manufacturing process in which the film exterior battery 10 needs to be pressurized one by one.

10 film exterior battery,
20 power generation elements,
30 positive electrode,
40 negative electrode,
50 film,
56 exterior body,
60 separator,
100 pressurizer,
101 Pressurization stage,
103 nut runner,
104 Control unit,
105 torque sensor,
106 encoder,
110 housing,
111 Movable plate (plate member),
111a guide hole,
112 guide rod,
113 Press plate,
114 drive rod,
Ta any torque,
Tb judgment torque (however, Ta <Tb),
θa The amount of rotation of the drive rod when an arbitrary torque (Ta) is reached,
The amount of rotation of the drive rod when the θb judgment torque (Tb) is reached,
α judgment value,
αs threshold,
T1 1st torque,
T2 second torque (however, T1 <T2),
T3 3rd torque (however, T2 <T3),
θ1 The amount of rotation of the drive rod when the first torque is reached,
θ2 The amount of rotation of the drive rod when the second torque is reached,
θ3 The amount of rotation of the drive rod when the third torque is reached,
α1 judgment value,
α2 judgment value,
αs1 first threshold,
αs2 Second threshold.

Claims (5)

In a method for manufacturing a flat film exterior battery in which a power generation element formed by laminating a positive electrode and a negative electrode via a separator is housed together with an electrolytic solution inside an exterior body made of a flexible film.
When the film exterior battery is sandwiched between paired plate members that can move relatively close to each other and the film exterior battery is pressurized by relatively approaching the pair of plate members as the drive rod rotates. In addition, the torque generated in the drive rod is detected.
When determining whether or not a pressurization failure of the film exterior battery has occurred in the section between the arbitrary torque (Ta) and the determination torque (Tb) (however, Ta <Tb), the arbitrary torque (Ta). ) And the torque change amount (Δθ) with respect to the angle difference (Δθ) between the rotation amount (θa) of the drive rod when the determination torque (Tb) is reached and the rotation amount (θb) of the drive rod when the determination torque (Tb) is reached. ΔT),
α = ΔT / Δθ = (Tb-Ta) / (θb-θa)
Is used as the judgment value
By comparing the determination value (α) with a predetermined threshold value (αs), the film exterior battery is pressurized in the section between the arbitrary torque (Ta) and the determination torque (Tb). A method for manufacturing a film exterior battery that determines whether or not a defect has occurred. The arbitrary torque (Ta) is the first torque (T1).
The determination torque (Tb) is a second torque (T2) (however, T1 <T2) that causes a pressing force to end the pushing of the electrolytic solution existing between the power generation element and the exterior body.
The rotation amount (θ1) of the drive rod when the determination value (α) reaches the first torque (T1) and the rotation amount (θ1) of the drive rod when the determination value (α) reaches the second torque (T2). The amount of change in torque (ΔT) with respect to the angle difference (Δθ) from θ2).
α1 = ΔT / Δθ = (T2-T1) / (θ2-θ1)
And
When the determination value (α1) is smaller than the predetermined first threshold value (αs1), the pushing of the electrolytic solution existing between the power generation element and the film is defective, and the film. The method for manufacturing a film exterior battery according to claim 1, wherein it is determined that a pressurization failure of the exterior battery has occurred. The arbitrary torque (Ta) is a second torque (T2) that generates a pressing force that terminates the pushing of the electrolytic solution existing between the power generation element and the exterior body.
The determination torque (Tb) is a third torque (T3) (however, T2 <T3) that generates a pressing force at which the pushing of the power generation element ends.
The rotation amount (θ2) of the drive rod when the determination value (α) reaches the second torque (T2) and the rotation amount (θ2) of the drive rod when the determination value (α) reaches the third torque (T3). The amount of change in torque (ΔT) with respect to the angle difference (Δθ) from θ3).
α2 = ΔT / Δθ = (T3-T2) / (θ3-θ2)
And
When the determination value (α2) is larger than the predetermined second threshold value (αs2), it is determined that galling that hinders the movement of the plate member has occurred and the pressurization failure of the film exterior battery has occurred. The method for manufacturing a film exterior battery according to claim 1. The method for manufacturing a film exterior battery according to any one of claims 1 to 3, wherein detection of whether or not a pressurization failure has occurred in the film exterior battery is performed before or during charging of the film exterior battery. .. The method for manufacturing a film exterior battery according to any one of claims 1 to 4, wherein it is detected whether or not a pressurization failure has occurred in a group including a plurality of the film exterior batteries.

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