JP7042049B2 - Inspection method using pallets and pallets - Google Patents

Description

The present invention relates to a pallet and an inspection method using the pallet.

For example, Patent Document 1 discloses a conductivity inspection device for a laminated structure battery in which an electrode laminate is exteriorized with an exterior film.

The conductivity inspection device in Patent Document 1 has a stage for holding a laminated structure battery at a predetermined position, and the laminated structure battery to be inspected is carried as a single item on this stage to perform a conductivity inspection. ing.

Japanese Unexamined Patent Publication No. 2013-164380

However, when inspecting a laminated structure battery with such a conventional conductivity inspection device, the laminated structure batteries are carried one by one to the stage of the conductivity inspection device, and after the inspection is completed, the stage of the conductivity inspection device is completed. Need to be carried out from.

That is, the process of inspecting the laminated structure battery performed by the conductivity inspection device is a process independent of other work processes. Therefore, the conductivity inspection device is a device located outside the transport line in various work processes other than the inspection process of the laminated structure battery.

Therefore, in Patent Document 1, the inspection process by the conductivity inspection device cannot be carried out on the same transfer line as various work processes other than this inspection process. That is, in manufacturing a laminated structure battery, there is room for further improvement so that various work processes can be carried out on the same transport line.

The pallet of the present invention has a central portion in which the upper surface on which the laminated structure battery is placed is a continuous flat surface, an outer peripheral portion that surrounds the periphery of the central portion and supports the central portion in a cantilevered state, and the central portion. Has a hole portion for separating the central portion from the outer peripheral portion so that the outer peripheral portion is cantilevered.

The central portion is set to a size that can support the entire lower surface of the electrode laminate, and the hole portion has a width that allows the passage of a heater that heat-welds the laminated films to each other around the electrode laminate. Is set to.

According to the present invention, when the laminated structure battery is pressurized and the conductivity of the laminated structure battery is inspected, it is not necessary to take out the laminated structure battery from the pallet and inspect it by an apparatus outside the transport line. It can be shortened.

The perspective view which shows an example of the laminated structure battery. Sectional drawing which shows an example of a laminated structure battery. Explanatory drawing schematically showing the outline of a laminating joining process. The perspective view which shows an example of the pallet which concerns on this invention. The perspective view which shows the pallet in the 1st laminating film loading stage. The perspective view which shows the pallet in the electrode laminated body loading stage. The perspective view which shows the pallet in the 2nd laminating film loading stage. It is explanatory drawing which showed the outline of the conductivity inspection apparatus schematically, (a) shows the state before pressurization, (b) shows the state after pressurization. Explanatory drawing schematically showing the movement of the pallet in the transport line leading to the conductivity inspection stage. The perspective view which shows an example of a work lifting table.

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

1 and 2 show a laminated structure battery 1 manufactured by using the pallet 30 of the present invention.

The laminated structure battery 1 is, for example, a lithium ion secondary battery, and as shown in FIG. 1, has a flat rectangular appearance shape, and a pair of positive and negative batteries made of a conductive metal foil at one end edge in the longitudinal direction. It is provided with terminals 2 and 3 of.

As shown in FIG. 2, the laminated structure battery 1 contains a rectangular electrode laminated body 4 together with an electrolytic solution inside an exterior body 5 made of a laminated film. The electrode laminate 4 is composed of similarly sheet-shaped positive electrodes 12 and negative electrodes 13 alternately laminated via a sheet-shaped separator 11, and is, for example, between 22 negative electrodes 13 and 21 positive electrodes 12. The 42 separators 11 and the above are included. The dimensions of each part and the number of separators 11 and the like in FIG. 2 are not accurate and are exaggerated or omitted for the sake of explanation.

The positive electrode 12 is formed by coating both surfaces of a positive electrode current collector 12a made of a metal foil, for example, an aluminum foil, with a positive electrode active material layer 12b. The positive electrode active material layer 12b is obtained by applying a mixture of a positive electrode active material made of lithium metal oxide, a conductive auxiliary agent such as carbon black, and a binder to the main surface of the positive electrode current collector 12a, and drying and drying. It is formed by rolling.

The negative electrode 13 is formed by forming negative electrode active material layers 13b on both sides of a negative electrode current collector 13a made of a metal foil, for example, a copper foil. The negative electrode active material layer 13b is formed by applying a mixture of a negative electrode active material such as amorphous carbon or graphite and a binder to the main surface of the negative electrode current collector 13a, drying and rolling.

A part of the longitudinal edge of the negative electrode current collector 13a extends as an extension portion that does not include the negative electrode active material layer 13b, and the tip thereof is joined to the negative electrode terminal 3. Further, although not shown in FIG. 2, similarly, a part of the longitudinal edge of the positive electrode current collector 12a extends as an extension portion not provided with the positive electrode active material layer 12b, and the tip thereof extends as a positive electrode terminal. It is joined to 2.

The separator 11 is sandwiched between the positive electrode 12 and the negative electrode 13 and has a function of preventing a short circuit between the two electrodes and at the same time holding an electrolyte. The separator 11 is made of, for example, a microporous film of a polyolefin-based synthetic resin such as polyethylene (PE) or polypropylene (PP), and when an overcurrent flows, the heat generated by the separator 11 closes the pores of the layer and cuts off the current. have.

The positive electrode 12, the negative electrode 13, and the separator 11 constitute an electrode laminate 4 in a state where a predetermined number of electrodes are laminated.

The exterior body 5 that houses the electrode laminate 4 together with the electrolytic solution has, for example, a three-layer structure in which a heat-sealing layer made of synthetic resin is laminated on the inside of an aluminum foil and a protective layer made of synthetic resin is laminated on the outside. It consists of a laminated film that has. More specifically, the exterior body 5 includes one laminated film (first laminated film 5a) arranged on the lower surface side of the electrode laminated body 4 of FIG. 2 and another laminated film (first laminated film 5a) arranged on the upper surface side. It has a two-sheet structure with the second laminating film 5b). That is, the exterior body 5 has a pair of upper and lower laminated films 5a and 5b, and the four sides around the two laminated films 5a and 5b are overlapped with each other and heat-sealed to each other. The first and second laminated films 5a and 5b have a laminated film structure in which a metal foil is sandwiched between resin layers.

The pair of terminals 2 and 3 located on the short side of the rectangular laminated structure battery 1 are drawn out through the joint surface of the laminated film when the laminated film is heat-sealed.

The laminated structure battery 1 is manufactured, for example, by the following procedure. First, in the laminating step, the positive electrode 12, the negative electrode 13, and the separator 11 are sequentially laminated, and the terminals 2 and 3 are attached by spot welding or the like to form the electrode laminated body 4.

Next, in the laminating bonding step, the electrode laminating body 4 is covered (sandwiched) with the first laminating film 5a and the second laminating film 5b to be the exterior body 5, and the surrounding three sides are heat-sealed, leaving one side. In this embodiment, the exterior body 5 has a two-sheet structure consisting of one first laminating film 5a arranged on the lower surface side of the electrode laminated body 4 and one second laminating film 5b arranged on the upper surface side. ing. That is, in the laminating body 5, the exterior body 5 is heat-welded by superimposing the four sides around the electrode laminated body 4 on each other, leaving an injection port for injecting the electrolytic solution on one side. Therefore, the exterior body 5 has a bag-like structure in which the injection port is opened in the laminating joining process.

Next, in the electrolytic solution injection step, the electrolytic solution is filled inside the exterior body 5 through one side to be opened, and then one side to be opened is heat-sealed to seal the exterior body 5. As a result, the laminated structure battery 1 is completed. Next, the battery is charged to an appropriate level, and in this state, aging is performed for a certain period of time. After the completion of this aging, the battery is recharged for voltage inspection and the like, and then shipped.

FIG. 3 is an explanatory diagram schematically showing an outline of the laminating joining process.

Reference numeral 20 in FIG. 3 is a linear pallet transfer conveyor composed of a friction conveyor that sequentially conveys the pallets 30 shown in detail in FIG.

Along the transfer line consisting of the pallet transfer conveyor 20, the first laminated film charging stage 21, the electrode laminated body charging stage 22, the second laminated film charging stage 23, the heat welding stage 24, the conductivity inspection stage 25, and the work unloading stage 26 Is placed.

The transport line for sequentially transporting the pallets 30 is not limited to the friction conveyor, and a lift and carry type conveyor or a linear conveyor (a robot type that moves with a magnet and has an independent slider) is used. It may be the one that has been used.

The pallet 30 is a plate-shaped member made of, for example, carbon fiber reinforced plastic (CFRP), and has a substantially rectangular outer shape.

The pallet 30 has a central portion 31, an outer peripheral portion 32 that supports the central portion 31 in a cantilevered state, a connecting portion 33 that connects the central portion 31 and the outer peripheral portion 32, and a central portion 31 with respect to the outer peripheral portion 32. It has a hole 34 formed so as to be in a cantilever state.

The central portion 31 has a rectangular flat plate shape, and the upper surface 31a is a continuous flat surface. Further, the central portion 31 is set to be larger than the lower surface (bottom surface) of the electrode laminate 4. That is, the central portion 31 is set to a size that can support the entire lower surface (entire bottom surface) of the electrode laminate 4.

The outer peripheral portion 32 is formed so as to surround the periphery of the central portion 31. The outer peripheral portion 32 includes a metal positive electrode terminal support plate 35 that supports the tip end side of the positive electrode terminal 2 of the electrode laminate 4, and a metallic negative electrode terminal support that supports the tip end side of the negative electrode terminal 3 of the electrode laminate 4. A plate 36 and a clamp arm 37 that presses the electrode laminated body 4 in the laminating direction are attached.

The clamp arm 37 mainly prevents the electrode laminated body 4 from being displaced during transportation, and when the electrode laminated body 4 is pressed, it is rotated 90 ° from the state shown in FIG. 4 and is located above the central portion 31. Become. The clamp arm 37 sandwiches the electrode laminated body 4 with the central portion 31, and presses the electrode laminated body 4 against the central portion 31. When applied to the shaft 38 of the clamp arm 37 with a ball spline, the clamp arm 37 can more reliably press the electrode laminate 4.

Further, the outer peripheral portion 32 is provided with a plurality of positioning protrusions 39 for positioning the first laminating film 5a and the second laminating film 5b with respect to the pallet 30. These positioning protrusions 39 are inserted into positioning holes (not shown) formed through the outer peripheral edges of the first laminating film 5a and the second laminating film 5b.

The connecting portion 33 connects the base end of the central portion 31 and the outer peripheral portion 32. A rectangular through hole 33a is formed in the connecting portion 33. The shape of the through hole 33a is not limited to a rectangle, and can be appropriately changed as long as it allows the passage of the second protrusion 62, which will be described later.

The hole portion 34 is a hole formed around the central portion 31 having a C-shape or a U-shape and penetrates the pallet 30, and separates the central portion 31 from the outer peripheral portion 32.

In the first laminating film charging stage 21, the first laminating film 5a is placed on the pallet 30 as shown in FIG.

In the electrode laminate loading stage 22, as shown in FIG. 6, the electrode laminate 4 is placed on the central portion 31 of the pallet 30 from above the first laminate film 5a. The entire lower surface of the electrode laminate 4 is supported by the central portion 31.

In the second laminating film charging stage 23, as shown in FIG. 7, the second laminating film 5b is placed on the pallet 30 from above the electrode laminate 4.

In the heat welding stage 24, the three sides of the rectangular first laminated film 5a and the second laminated film 5b are sandwiched by a pair of heat blocks (not shown), and the two are heat-welded by pressurizing and heating. .. At this time, of the pair of heat blocks, the lower heat block as a heater is pressed against the first laminating film 5a through the hole 34 of the pallet 30. That is, the hole 34 of the pallet 30 is set to have a width that allows the passage of the lower heat block.

At the conductivity inspection stage 25, the conductivity inspection is performed using the conductivity inspection device 50 shown in FIG. The conductivity inspection carried out by the conductivity inspection apparatus 50 is known, for example, according to Japanese Patent Application Laid-Open No. 2013-164380, and may reach the metal foil of the first laminate film 5a and the metal foil of the second laminate film 5b. A metallic needle (not shown) is inserted into the electrode laminate 4 to inspect the conduction state between the electrode laminate 4 and the needle.

In this embodiment, in the conductivity inspection stage 25, the conductivity inspection is performed by the conductivity inspection device 50 in a state where the laminated structure battery 1 is pressurized in the stacking direction of the electrode laminate 4.

FIG. 8A shows a state before the laminated structure battery 1 is pressurized in the laminating direction of the electrode laminated body 4. FIG. 8B shows a state in which the laminated structure battery 1 is pressurized in the stacking direction of the electrode laminated body 4 and the conduction state between the electrode laminated body 4 and the needle is inspected. The needle is inserted into the laminated structure battery 1 when the laminated structure battery 1 is pressed in the stacking direction of the electrode laminated body 4.

The conductivity inspection device 50 is roughly composed of a first unit 51 located above the pallet 30 and a second unit 52 located below the pallet 30.

The first unit 51 has a first pressing pad 53 that is pressed against the upper surface side of the central portion 31 of the pallet 30, and a first support member 54 to which the first pressing pad 53 is attached.

The first pressing pad 53 can be pressed against the second laminating film 5b mounted on the pallet 30. The first support member 54 is moved up and down by a first air cylinder (not shown). Further, the needle is attached to the first support member 54. That is, the needle moves up and down with the vertical movement of the first support member 54.

The second unit 52 has a second pressing pad 56 pressed against the lower surface side of the central portion 31 of the pallet 30, and a second support member 57 to which the second pressing pad 56 is attached.

The second pressing pad 56 can be pressed against the lower surface (back surface) of the central portion 31 of the pallet 30. The second support member 57 is moved up and down by the second air cylinder 58. Note that 59 in FIG. 8 is a guide member that guides the vertical movement of the second support member 57.

That is, the first unit 51 and the second unit 52 can pressurize the laminated structure battery 1 in the laminating direction of the electrode laminated body 4.

In the conductivity inspection by the conductivity inspection device 50, in the laminated structure battery 1 in which the periphery of the electrode laminate 4 is heat-welded, the positive electrode 12 of the electrode laminate 4 is between the first and second laminate films 5a and 5b. The conductivity between the negative electrode 13 and the negative electrode 13, between the positive electrode 12 and the exterior body 5 of the electrode laminate 4, and between the negative electrode 13 and the exterior body 5 of the electrode laminate 4 is inspected, and a defective product of the laminated structure battery 1 is found. Sort.

In order not to overlook the defective product of the laminated structure battery 1 as much as possible in the conductivity inspection, it is effective to pressurize the laminated structure battery 1 in the stacking direction. By pressurizing the laminated structure battery 1 at the time of carrying out the conductivity inspection, for example, contamination in the electrode laminate 4, holes in the separator 11 in the electrode laminate 4, turning of the separator 11 in the electrode laminate 4, etc. Abnormalities caused by can be manifested.

Further, in the conductivity inspection stage 25, as shown in FIG. 9, the pallet 30 can be horizontally conveyed from the previous stages such as the second laminating film charging stage 23 and the heat welding stage 24.

At the work unloading stage 26, the laminated structure battery 1 is unloaded from the pallet 30. At this time, the laminated structure battery 1 mounted on the pallet 30 is lifted from the pallet 30 by raising the work lifting table 60 shown in FIG. The work lifting table 60 can be moved up and down by a drive unit such as an air cylinder (not shown).

The work lifting table 60 has a first protrusion 61, 61 as a first push-up member that can pass through the hole 34 of the pallet 30, and a second protrusion as a second push-up member that can pass through the through hole 33a of the pallet 30. It has a portion 62 and. In other words, the hole portion 34 is set to have a width that allows the passage of the first protrusion portion 61. Further, the through hole 33a is set to have a width that allows the passage of the second protrusion 62.

The first protrusion 61 is an L-shaped protrusion. The second protrusion 62 is a rectangular parallelepiped-shaped protrusion.

As a result, an appropriate gap is formed between the pallet 30 and the laminated structure battery 1, and a robot hand (not shown) can be inserted into this gap to take out the laminated structure battery 1.

The laminated structure battery 1 before injecting the electrolytic solution carried out from the pallet 30 in the work carrying-out stage 26 is stored in a predetermined magazine located outside the carrying-out line.

In the pallet 30 of this embodiment, the entire upper surface of the central portion 31 is a flat surface. Therefore, in the central portion 31 of the pallet 30, it is possible to pressurize the entire surface of the electrode laminated body 4 with the laminated structure battery 1 mounted.

That is, in the laminating bonding step, the laminated structure battery 1 can be pressurized as it is while being placed on the pallet 30 which was placed when the periphery of the electrode laminated body 4 was heat-welded.

That is, it is possible to carry out a conductivity test in which the laminated structure battery 1 is pressurized while being placed on the same pallet 30 after the periphery of the electrode laminated body 4 is sealed by using the hole portion 34.

Further, the laminated structure battery 1 is subjected to the work of heat-welding the three sides around the electrode laminated body 4 sandwiched between the exterior bodies 5 and the state where the three sides around the electrode laminated body 4 are heat-welded. It is possible to carry out the work of inspecting the conductivity by pressing on the same line (same transfer line).

Therefore, when the laminated structure battery 1 is pressurized and inspected for conductivity in the laminating bonding step, it is not necessary to take out the laminated structure battery 1 from the transport line and inspect it with a device outside the transport line, so that the work time is generally shortened. Can be realized. That is, the productivity of the laminated structure battery 1 can be improved as a whole.

Further, since the central portion 31 is supported by the outer peripheral portion 32 via the connecting portion 33 in a cantilevered state, the central portion 31 is changed to the outer peripheral portion 32 when the laminated structure battery 1 placed in the central portion 31 is pressurized. Can be bent against. Therefore, the laminated structure battery 1 can be uniformly pressurized at the central portion 31 of the pallet 30. Further, even if the thickness of the pallet 30 varies, the central portion 31 can be bent with respect to the outer peripheral portion 32, so that the laminated structure battery 1 can be uniformly pressurized at the central portion 31 of the pallet 30. can.

Since the hole 34 is set to have a width that allows the passage of the first protrusion 61 that pushes up the laminated structure battery 1 mounted on the pallet 30, the laminated structure battery 1 can be easily taken out from the pallet 30. can.

The connecting portion 33 is formed with a through hole 33a that allows the passage of the second protrusion 62 that pushes up the laminated structure battery 1. Therefore, when the laminated structure battery 1 is lifted from the pallet 30, the entire circumference of the laminated structure battery 1 is supported by the first and second protrusions 61 and 62. That is, the laminated structure battery 1 can be taken out from the pallet 30 without disturbing the posture of the laminated structure battery 1.

Further, by using the pallet 30 of the above-described embodiment, the exterior body 5 around the electrode laminated body 4 is heat-welded by the heater that has passed through the hole 34 on the same transport line using the same pallet 30. After that, the exterior body 5 and the electrode laminate 4 are pressurized while being placed on the pallet 30, and a metal needle is inserted so as to reach the metal foil of the exterior body from the surface of the exterior body 5, and the electrode laminate 4 and the above are described. It becomes possible to inspect the continuity state with the needle.

1 ... Laminated structure battery 4 ... Electrode laminated body 5 ... Exterior body 5a ... First laminated film 5b ... Second laminated film 30 ... Palette 31 ... Central portion 31a ... Top surface 32 ... Outer peripheral portion 33 ... Connecting portion 33a ... Through hole 34 ... Hole

Claims (5)

A laminated structure in which an electrode laminate is sandwiched between a pair of upper and lower laminated films.
An outer peripheral portion that surrounds the periphery of the central portion and supports the central portion in a cantilevered state.
A connecting portion that connects the central portion and the outer peripheral portion,
It has a hole portion for separating the central portion from the outer peripheral portion so that the central portion is cantilevered with respect to the outer peripheral portion.
The central portion is set to a size that can support the entire lower surface of the electrode laminate.
The pallet is characterized in that the hole portion is set to have a width that allows the passage of a heater that heat-welds the pair of upper and lower laminated films to each other around the electrode laminate. The pallet according to claim 1, wherein the hole portion is set to have a width that allows the passage of the first push-up member that pushes up the laminated structure battery. The pallet according to claim 1 or 2, wherein the connecting portion is formed with a through hole that allows the passage of the second push-up member that pushes up the laminated structure battery. The pallet according to any one of claims 1 to 3, wherein the pallet is made of carbon fiber reinforced plastic. The upper surface becomes a continuous flat surface, and the central part is set to a size that can support the entire lower surface of the electrode laminate.
An outer peripheral portion that surrounds the periphery of the central portion and supports the central portion in a cantilevered state.
Using a pallet having a hole portion for separating the central portion from the outer peripheral portion so that the central portion is cantilevered with respect to the outer peripheral portion.
The electrode laminate, which is covered with a laminate film having a laminated film structure in which a metal foil is sandwiched between resin layers, is supported by the center portion of the pallet, and the electrode laminate is subjected to a heater that has passed through the hole portion. The surrounding laminated film is heat-welded, and then the electrode laminate is covered with the laminated film while being placed on the pallet, and the metal needle is inserted from the surface of the laminated film to the metal foil. An inspection method using a pallet, which comprises inserting and inspecting the continuity state between the electrode laminate and the needle.

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