Battery pack manufacturing method and battery pack

Abstract

The main purpose of the present disclosure is to provide a method for manufacturing a battery pack capable of efficiently hardening an adhesive while suppressing heating of a single cell. In the present disclosure, the above problem is solved by providing a method for manufacturing the battery pack. A method for manufacturing a battery pack, the method comprising a preparation step for preparing a laminated battery comprising a plurality of unit cells laminated in the thickness direction, a housing step for housing the laminated battery in a battery case, and a filling step for filling the laminated battery in the battery case, and a filling step for filling the battery case with an adhesive and fixing the laminated battery to the battery case, the adhesive containing a main agent, a curing agent, and a filler. The filling step has a discharge process for discharging the adhesive from a nozzle and a heating process for heating the adhesive discharged from the nozzle by irradiation with infrared rays, and the infrared rays are irradiated on the adhesive during the discharge process.

Description

Technical Field

[0001] The present disclosure relates to a method of manufacturing a battery pack and a battery pack. Background Art

[0002] A battery pack is known in which a plurality of single cells are housed in a battery case and the single cells are fixed to the battery case with an adhesive. Also known is a method for manufacturing such a battery pack.

[0003] For example, Patent Document 1 discloses a battery pack that fixes a single cell by bonding the inner surface of a shell to the outer surface of a single cell by reactive hot melt. In addition, Patent Document 2 discloses a battery pack that includes: a battery stack in which a plurality of batteries are arranged, a shell that accommodates the battery stack, and a heat-conductive layer composed of a heat-conductive thermosetting adhesive filled in the gap between the battery stack and the shell. In addition, although not directly related to the manufacturing method of the battery pack, Patent Document 3 discloses a resin filling method that uses resin to mold and integrally encapsulate the coil constituting the motor. In Patent Document 3, the resin is filled while applying current to the coil to generate heat.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-243364

[0007] Patent Document 2: Japanese Patent Application Publication No. 2021-140914

[0008] Patent Document 3: Japanese Patent Application Publication No. 2020-092521 Summary of the invention

[0009] Problems to be solved by the invention

[0010] When manufacturing a battery pack, it is assumed that an adhesive is filled into a battery case that accommodates a single cell, and the single cell is fixed to the battery case using the hardened adhesive. Here, in the case where the adhesive is a so-called two-liquid hardening type adhesive containing a main agent and a hardener, it is assumed that the adhesive is heated to promote hardening. On the other hand, when the electrode layer in the single cell is heated by heating the adhesive, there is a concern that the battery performance will be reduced.

[0011] The present disclosure has been made in view of the above circumstances, and a main object thereof is to provide a method for manufacturing a battery pack that can efficiently cure an adhesive while suppressing heating of a single cell.

[0012] Means of solving problems [1]

[0014] A method for manufacturing a battery pack, the method comprising a preparation step, a housing step and a filling step, the preparation step being a step of preparing a stacked battery having a plurality of single cells stacked in a thickness direction, the housing step being a step of housing the stacked battery in a battery case, the filling step being a step of filling an adhesive into the battery case and fixing the stacked battery to the battery case, the adhesive comprising a main agent, a hardener and a filler, the filling step comprising a spraying process of spraying the adhesive from a nozzle and a heating process of heating the adhesive sprayed from the nozzle by irradiation of infrared rays, the infrared rays irradiating the adhesive during spraying. [2]

[0016] In the manufacturing method described in [1] above, the filler is at least one of a black pigment and a black ceramic. [3]

[0018] In the production method described in [1] or [2] above, the heat treatment is a treatment in which the temperature of the adhesive is heated from room temperature to 40° C. or higher. [4]

[0020] A battery pack having a stacked battery and a battery case, wherein the stacked battery is accommodated in the battery case, the stacked battery has a plurality of single cells stacked in a thickness direction, and the stacked battery is fixed to the battery case by an adhesive, wherein the adhesive contains a main agent, a curing agent, and a filler. [5]

[0022] In the battery pack described in [4], the filler is at least one of a black pigment and a black ceramic.

[0023] Effects of the Invention

[0024] In the present disclosure, there is an effect that the adhesive can be cured efficiently while suppressing heating of the single cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram showing an example of a method for manufacturing a battery pack in the present disclosure.

[0026] Figure 2 This is a schematic cross-sectional view showing an example of a single cell in the present disclosure.

[0027] Figure 3 This is a schematic cross-sectional view showing an example of a battery case in the present disclosure.

[0028] Figure 4 This is a schematic perspective view showing an example of the shape of the nozzle in the present disclosure. DETAILED DESCRIPTION

[0029] The manufacturing method and the battery pack in the present disclosure are described in detail below. The drawings shown below are exemplary, and the size and shape of each part are exaggerated in some cases for easy understanding.

[0030] A. Method of Manufacturing a Battery Pack

[0031] Figure 1 : is a schematic diagram showing an example of the manufacturing method in the present disclosure. Specifically, Figure 1 (a) is a schematic side view showing an example of a laminated battery prepared in the preparation step. Figure 1 (b) is a schematic plan view showing an example of the storage process. Figure 1 (c) Yes Figure 1 (b) AA cross-sectional view. Figure 1 (d) is a schematic plan view showing an example of the filling process. Figure 1 (e) Yes Figure 1 (d) AA cross-sectional view.

[0032] like Figure 1 As shown in (a), in the manufacturing method of the present disclosure, first, a T A stacked battery 100 of a plurality of single cells 10 stacked on top (preparation step). Figure 1 As shown in (b) and (c), the stacked body 100 is housed in the battery case 200 (housing step). Figure 1 As shown in (d) and (e), the battery case 200 is filled with adhesive F to fix the stacked battery 100 to the battery case 200 (filling process). The adhesive F contains a main agent, a hardener, and a filler. In addition, the filling process includes a predetermined spraying process and a predetermined heating process. Figure 1 As shown in (d) and (e), the ejection process is a process of ejecting the adhesive F from the nozzle 400. In addition, the heating process is a process of heating the adhesive F ejected from the nozzle 400 by irradiation with infrared rays IR. Figure 1 As shown in (e), infrared rays IR are irradiated onto the adhesive F in the process of being discharged.

[0033] According to the present disclosure, infrared rays are irradiated onto the adhesive in the process of being discharged to heat the adhesive, so that the heating of the single cell is suppressed and the adhesive can be cured efficiently.

[0034] For example, it is assumed that when the adhesive filled in the battery case is heated, the entire battery case is heated. In this regard, there is a concern that the stacked batteries housed in the battery case will also be heated, causing the electrode layers in the battery to deteriorate. Furthermore, from the perspective of heat capacity, such a heating method is not efficient.

[0035] On the other hand, in the method disclosed in the present invention, only the adhesive can be heated by infrared rays. Therefore, the adhesive can be efficiently heated and hardened. In addition, the adhesive in the present invention contains a filler. Since the filler absorbs infrared rays, the heating of the adhesive can be promoted. Furthermore, in the method disclosed in the present invention, infrared rays are irradiated to the adhesive in the process of being sprayed. Therefore, the single cell is not directly irradiated with infrared rays, and the heating of the single cell can be suppressed. In addition, even in the case of using a battery case that does not transmit infrared rays, the adhesive can be efficiently heated. Furthermore, since infrared rays are used, there is no worry about the adhesive scattering.

[0036] 1. Preparation process

[0037] The preparation step in the present disclosure is a step of preparing a stacked battery having a plurality of unit cells stacked in the thickness direction.

[0038] Figure 2 2 is a schematic cross-sectional view showing an example of a single cell in the present disclosure. Figure 2 As shown, the single cell 10 generally has an electrode E. The electrode E has a current collector 1 and an electrode layer (a positive electrode active material layer 2 or a negative electrode active material layer 3). T The current collector 1 is disposed on at least one side thereof. Figure 2 As shown, the single cell 10 may also have a bipolar electrode BP as an electrode E. The bipolar electrode BP has a positive electrode active material layer 2 arranged on one surface of the current collector 1. In addition, the bipolar electrode BP has a negative electrode active material layer 3 arranged on the other surface of the current collector 1 in the thickness direction. In addition, the single cell in the present disclosure may not have a bipolar electrode.

[0039] Figure 2 The single cell 10 shown in the figure has bipolar electrodes (BP1 and BP2), a positive electrode end electrode CA, and a negative electrode end electrode AN as electrodes. The bipolar electrodes are as described above. The positive electrode end electrode CA has a current collector 1 and a positive electrode active material layer 2 arranged on one surface of the current collector 1. The negative electrode end electrode AN has a current collector 1 and a negative electrode active material layer 3 arranged on one surface of the current collector 1. In addition, although not specifically shown in the figure, the single cell is usually sealed by an outer packaging body such as a laminated film.

[0040] In addition, if Figure 2 As shown, the single cell 10 is generally equipped with power generation units U (U1, U2, U3). The power generation unit U has a positive electrode active material layer 2, a negative electrode active material layer 3 and a separator (electrolyte layer) 4. The separator 4 is arranged between the positive electrode active material layer 2 and the negative electrode active material layer 3. Figure 2The power generation unit U shown is sealed by a sealing member 5 and a cover member 6. In addition, the inside of the power generation unit U is filled with an electrolyte 7. As a result, the electrolyte is impregnated in the positive electrode active material layer 2, the negative electrode active material layer 3 and the separator 4. The single cell may have one power generation unit or may have two or more power generation units.

[0041] The current collector (positive electrode current collector and negative electrode current collector) may be a conventionally known member. The electrode layer (positive electrode active material layer and negative electrode active material layer) may be a conventionally known member. The separator may be a conventionally known member.

[0042] The single cell may be an all-solid battery containing a solid electrolyte as an electrolyte. The single cell may be a liquid battery containing a liquid electrolyte (electrolyte) as an electrolyte. The single cell is typically a lithium-ion battery.

[0043] The planar shape of the single cell (the shape observed from the thickness direction) is, for example, a square or a rectangle. The length of each side constituting the planar shape of the single cell is, for example, greater than 30 cm. The length of the side may also be greater than 60 cm, or may be greater than 100 cm. On the other hand, the length of the above-mentioned side is, for example, less than 200 cm.

[0044] In the stacked battery, the number of single cells is 2 or more. The number of single cells may be 3 or more, 5 or more, or 10 or more. On the other hand, the number of single cells is, for example, 50 or less.

[0045] like Figure 1 As shown in (a), the stacked body 100 may include an intermediate member 20. The intermediate member is disposed between the plurality of cells stacked in the thickness direction. In the battery pack, the intermediate member functions as a cooling member for cooling the cells.

[0046] 2. Collection process

[0047] The housing step in the present disclosure is a step of housing the above-mentioned stacked body in a battery case.

[0048] like Figure 1 As shown in (b) and (c), in the housing step, the stacked battery 100 is usually housed with a gap between the stacked battery 100 and the inner surface of the battery case 200 (the wall of the battery case to be described later). Figure 1 As shown in (b), in the housing step, the control device 300 may be housed together with the laminated battery 100 in the battery case 200. The control device performs various controls on the battery.

[0049] Figure 3 2 is a schematic cross-sectional view showing a battery case as an example. Figure 3As shown, the cross-sectional shape of the battery case 200 is generally a concave shape having a bottom 201, a wall 202, and a flange 203. In addition, the so-called "inside the battery case" can be considered to be in the thickness direction D T The space on the bottom 201 side is larger than the flange 203. There is no particular limitation on the material of the battery case and any material known in the art may be used.

[0050] 3. Filling process

[0051] The filling step in the present disclosure is a step of filling the battery case with an adhesive and fixing the laminated battery to the battery case. In particular, the filling step in the present disclosure includes a predetermined ejection process and a heating process.

[0052] like Figure 1 As shown, in the filling step, the adhesive is preferably filled so as to surround the entire periphery of the stacked battery 100. The amount of the adhesive filled is, for example, an amount that allows all the cells in the stacked battery to come into contact with the adhesive.

[0053] The adhesive in the filling process contains a main agent and a hardener. That is, the adhesive is a so-called two-liquid hardening type adhesive. In addition, the adhesive contains a filler. As the filler, for example, black pigment and black ceramic can be listed. Since black pigment and black ceramic absorb infrared rays better, the heating of the adhesive can be further promoted. The adhesive may contain only one of the black pigment and the black ceramic. The adhesive may also contain both the black pigment and the black ceramic. As the black pigment, the black pigment known in the past can be listed. As the black ceramic, the black ceramic known in the past can be listed. The proportion of the filler in the adhesive is, for example, more than 5% by weight and less than 50% by weight.

[0054] As the adhesive, in addition to containing the above-mentioned filler, there can be mentioned a conventionally known two-component curing adhesive. As the adhesive, there can be mentioned an epoxy adhesive and a urethane adhesive.

[0055] (1) Ejection treatment

[0056] The spraying process is a process of spraying the adhesive from the nozzle. The spraying process is continued until a predetermined amount of the adhesive is filled into the battery case.

[0057] like Figure 1 As shown in (e), the nozzle 400 is usually arranged above the battery case 200 (above the flange 203). And, the adhesive F is sprayed into the gap between the battery case 200 and the stacked body 100. Figure 1 As shown in (d), it is preferable to discharge the adhesive F while scanning the nozzle 400 along the gap.

[0058] like Figure 4 As shown, the shape of the nozzle 400 is preferably a shape that sprays the adhesive F in a curtain shape. In other words, the nozzle is preferably a curtain-type nozzle because it can increase the area irradiated by infrared rays.

[0059] The adhesive is preferably sprayed from the nozzle in a state of a mixture of a main agent, a hardener and a filler. In addition, the temperature of the sprayed adhesive is preferably room temperature. Here, the so-called "room temperature" refers to a temperature above 15°C and below 25°C. In addition, the speed of spraying the adhesive is, for example, above 5cc / second and below 20cc / second. In addition, the spraying direction (spraying angle) of the nozzle is preferably parallel to the thickness direction. In addition, the so-called "parallel" does not mean parallel in a strict sense. That is, "parallel" in the present disclosure does not only mean the case where the angle formed by the two directions is 0°. In the present disclosure, the so-called "parallel" means that the angle formed by the two directions is above 0° and below 30°.

[0060] (2) Heating treatment

[0061] The heating treatment is a treatment for heating the adhesive ejected from the nozzle by irradiation of infrared rays. In the heating treatment, the infrared rays are irradiated to the adhesive in the process of being ejected. The so-called "adhesive in the process of being ejected" can be understood as the adhesive that has not yet been arranged in the battery case. For example, Figure 1 (e) and Figure 4 As shown, in the thickness direction D T On the other hand, infrared rays IR are irradiated to the adhesive F located between the nozzle 400 and the battery case 200 (the flange portion 203 of the battery case 200 ).

[0062] like Figure 1 As shown in (e), infrared rays are usually irradiated from a heat source 500. The heat source can be a concentrated light or a laser. Figure 1 As shown in (d), the heat source 500 may irradiate infrared rays while following the scanning of the nozzle 400 .

[0063] Preferably, the heat treatment heats the temperature of the adhesive from room temperature to 40° C. or higher. The heat treatment may also heat the temperature of the adhesive to 50° C. or higher. The heat treatment may also heat the temperature of the adhesive to 60° C. or higher.

[0064] There is no particular limitation on the type of infrared rays. The infrared rays may be near infrared rays, intermediate infrared rays, or far infrared rays. Among them, near infrared rays are preferred.

[0065] B. Battery Pack

[0066] The battery pack in the present disclosure has a stacked battery and a battery case. The stacked battery is housed in the battery case. The stacked battery has a plurality of cells stacked in the thickness direction. The stacked battery is fixed to the battery case by an adhesive. The adhesive contains a main agent, a hardener, and a filler. In addition, the battery pack may also have a cover that closes the battery case filled with the adhesive.

[0067] The laminated battery, the battery case and the adhesive are as described above. In addition, the cover may be made of a conventionally known material.

[0068] There is no particular limitation on the use of the battery pack. The battery pack can be used as a power source for a vehicle. As vehicles, for example, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles can be listed. Particularly preferably, the battery pack is used as a driving power source for a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) or an electric vehicle (BEV). The battery pack can also be used as a power source for mobile bodies other than vehicles (for example, railways, ships, and aircraft). The battery pack can also be used as a power source for electrical products such as information processing devices.

[0069] The present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are exemplary, and any mode having substantially the same structure as the technical concept described in the claims of the present disclosure and having the same function and effect is included in the technical scope of the present disclosure.

[0070] Description of Reference Numerals

[0071] 1. Current Collector

[0072] 2 Positive electrode active material layer

[0073] 3 Negative electrode active material layer

[0074] 4 Diaphragm

[0075] E Electrode

[0076] 10 single battery

[0077] 100 stacked batteries

[0078] 200 Battery housing

[0079] 300 Control Equipment

[0080] 400 Nozzle

[0081] 500 Heat Source

Claims

1. A method for manufacturing a battery pack, wherein: The method comprises a preparation process, a receiving process and a filling process, wherein the preparation process is a process of preparing a stacked battery having a plurality of single cells stacked in a thickness direction, the receiving process is a process of receiving the stacked battery in a battery case, the filling process is a process of filling an adhesive into the battery case and fixing the stacked battery to the battery case, the adhesive comprising a main agent, a hardener and a filler, and the filling process comprises a spraying process of spraying the adhesive from a nozzle and a heating process of heating the adhesive sprayed from the nozzle by irradiation of infrared rays, the infrared rays irradiating the adhesive during spraying.

2. The manufacturing method according to claim 1, wherein: The filler is at least one of a black pigment and a black ceramic.

3. The manufacturing method according to claim 1 or 2, wherein: The heating treatment is a treatment for heating the temperature of the adhesive from room temperature to 40° C. or higher.

4. A battery pack having a stacked battery and a battery casing, wherein: The laminated battery is accommodated in the battery case. The laminated battery includes a plurality of single cells laminated in a thickness direction. The laminated battery is fixed to the battery case by an adhesive. The adhesive contains a main agent, a curing agent, and a filler.

5. The battery pack according to claim 4, wherein: The filler is at least one of a black pigment and a black ceramic.

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