Assembled battery and method for dismantling same

Abstract

To provide a battery pack in which a bus bar can be cut with high accuracy in a manner not to damage a secondary battery.SOLUTION: A battery pack disclosed herein includes a plurality of secondary batteries and a bus bar that electrically connects the plurality of secondary batteries. Each of the plurality of secondary batteries includes a battery case. The battery pack is provided with information on cutting positions of the bus bar when the battery pack is disassembled.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a battery pack. The present invention also relates to a method for dismantling the battery pack. [Background technology]

[0002] In recent years, secondary batteries such as lithium ion secondary batteries have been suitably used as vehicle driving power sources, etc. In vehicle driving power sources, secondary batteries are generally used in the form of assembled batteries in which multiple secondary batteries (i.e., single cells) are electrically connected by bus bars (see, for example, Patent Document 1).

[0003] In order to reduce waste and make effective use of resources, used assembled batteries are collected and recycled. To recycle them, the assembled batteries are first disassembled into individual cells by cutting the bus bars of the assembled batteries. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-212155 A Summary of the Invention [Problem to be solved by the invention]

[0005] When cutting the busbars of a battery pack, there is a risk of damaging the secondary batteries. Because the secondary batteries included in the battery pack may be in a charged state, it is desirable to avoid damaging the secondary batteries as much as possible. Therefore, there is a need to develop a technology that can cut the busbars with precision without damaging the secondary batteries.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a battery pack that enables bus bars to be cut with high accuracy without damaging the secondary batteries. [Means for solving the problem]

[0007] The battery pack disclosed herein includes a plurality of secondary batteries and a bus bar that electrically connects the plurality of secondary batteries. Each of the plurality of secondary batteries includes a battery case. The battery pack is provided with information on the cutting positions of the bus bar when the battery pack is disassembled.

[0008] With this configuration, the bus bar can be cut with high precision so as not to damage the secondary battery.

[0009] From another aspect, the method of dismantling a battery pack disclosed herein includes the steps of preparing a battery pack in which a plurality of secondary batteries are electrically connected by a bus bar (wherein each of the plurality of secondary batteries includes a battery case, and information on the cutting position of the bus bar when dismantling the battery pack is provided to the battery pack), confirming the cutting position, and cutting the bus bar at the cutting position.

[0010] With this configuration, the bus bar can be cut with high precision so as not to damage the secondary battery. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a schematic diagram of a battery pack according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view showing a schematic diagram of a single cell of the battery pack according to the first embodiment. [Diagram 3] 2 is a perspective view showing a schematic diagram of an example of a bus bar of the battery pack according to the first embodiment. FIG. [Figure 4] 2 is a schematic diagram of a battery pack according to the first embodiment having a bus bar plate. FIG. [Diagram 5] FIG. 2 is a schematic diagram showing a configuration in which a spacer of the battery pack according to the first embodiment protects a side surface of a unit cell. [Figure 6] FIG. 11 is a perspective view that illustrates an example of a single cell of a battery pack according to a second embodiment. [Figure 7] FIG. 11 is a perspective view showing a schematic example of a bus bar of a battery pack according to a third embodiment. [Figure 8] 13 is a perspective view showing a schematic diagram of another example of the bus bar of the battery pack according to the third embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Matters not mentioned in this specification but necessary for carrying out the present invention can be understood as design matters for a person skilled in the art based on the prior art in the relevant field. The present invention can be carried out based on the contents disclosed in this specification and the technical common sense in the relevant field. In addition, in the following drawings, members and parts having the same function are described with the same reference numerals. Furthermore, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. In addition, the numerical range expressed as "A to B" in this specification includes A and B.

[0013] In this specification, the term "secondary battery" refers to an electricity storage device that can be repeatedly charged and discharged. In addition, in this specification, the term "lithium ion secondary battery" refers to a secondary battery that uses lithium ions as a charge carrier and realizes charging and discharging by the transfer of charge associated with the lithium ions between the positive and negative electrodes.

[0014] First Embodiment As an example of the battery pack disclosed herein, a battery pack according to a first embodiment will be described below with reference to Figs. 1 to 3. Fig. 1 is a perspective view that typically shows the battery pack according to the first embodiment. Fig. 2 is a perspective view that typically shows a cell of the battery pack according to the first embodiment. Fig. 3 is a perspective view that typically shows a bus bar of the battery pack according to the first embodiment.

[0015] (Battery pack) As shown in Fig. 1, the battery pack 100 according to this embodiment includes a plurality of unit cells 1 arranged along a predetermined arrangement direction. Specifically, in this battery pack 100, the plurality of unit cells 1 each having a flat rectangular battery case 10 (see Fig. 2) are arranged along a depth direction Y with their flat surfaces facing each other. Thus, the depth direction Y is the arrangement direction of the unit cells 1. In the battery pack 100 according to this embodiment, the arranged unit cells 1 are electrically connected to each other by bus bars 110.

[0016] In the illustrated example, a pair of end plates 120 are arranged on both outer sides in the arrangement direction (depth direction Y) of the battery pack 100. The pair of end plates 120 are bridged by a restraining beam 130, thereby restraining each of the multiple unit cells 1 along the arrangement direction. In the illustrated example, a spacer 140 is arranged between adjacent unit cells 1 to equalize the restraining pressure on the flat surfaces of the unit cells 1. The end plates 120, the restraining beam 130, and the spacer 140 may have any configuration.

[0017] (Busbar) The bus bar 110 is a conductive member for electrically connecting the cells 1. As shown in Fig. 1, the cells 1 are arranged in the depth direction Y such that the electrode terminals 20 are adjacent to each other, and the bus bar 110 is disposed to bridge the adjacent electrode terminals 20. The cells 1 are electrically connected to each other via the bus bar 110 to form the battery pack 100.

[0018] Busbar 110 and electrode terminal 20 are joined in surface contact with each other. This joining is achieved by laser joining or the like. Although not particularly limited, the constituent material of busbar 110 is a metal material having excellent conductivity and strength, such as aluminum or an aluminum alloy. Busbar 110 has a flat plate shape, but the shape of busbar 110 is not limited to this.

[0019] In the first embodiment, information on the cutting positions when dismantling busbar 110 is provided to busbar 110. In the first embodiment, the information on the cutting positions is provided by, for example, attaching, printing, or engraving. In the example shown in Fig. 3, a sticker 160 including information on the cutting positions is attached to busbar 110.

[0020] The cutting position when dismantling the busbar 110 is usually a position between one cell 1 and an adjacent cell 1 in the depth direction Y (i.e., the arrangement direction of the cells 1) so as not to damage the cells 1 during cutting. Therefore, it is advantageous to have a distance between the cell 1 and the adjacent cell 1, and it is particularly advantageous to ensure the distance between the adjacent cells 1 by the spacer 140.

[0021] The information on the cutting position may be a code such as a character code, a one-dimensional code (e.g., a barcode), a two-dimensional code (e.g., a QR code (registered trademark)), or an RFID. In the illustrated example, a QR code (registered trademark) 150 is printed on a sticker 160 as the information on the cutting position. The sticker 160 is advantageous because the information on the cutting position can be added after the battery pack 100 is completed. In this specification, the term "sticker" includes "decal" and "label."

[0022] However, if the cut location information is coded, the code may be printed or engraved directly onto the busbar 110. As an alternative method of providing the cut location information onto the busbar 110, the busbar 110 may be printed with solid or dashed lines at the cut locations.

[0023] In order to make the information on the cutting position readable, the information on the cutting position is typically provided on a portion of the busbar 110 that is exposed in the configuration of the battery pack 100. Therefore, in the illustrated example, the information on the cutting position is provided on the exposed surface of the busbar 110, i.e., the upper surface of the busbar 110, for easy recognition. However, in cases such as when a sticker-type RFID tag is used, the information does not need to be provided on the exposed surface of the busbar 110, and even in such cases, the information can be read. The battery pack 100 is usually installed so that the surface with the electrode terminals 20 faces upward, and in this specification, the surface on the upper side in the normal installation configuration of the battery pack 100 is referred to as the "upper surface". Similarly, the surface on the side of the battery pack 100 in the normal installation configuration is referred to as the "side surface".

[0024] In battery pack 100, only one bus bar 110 may be provided with the information on the cut position, or multiple bus bars 110 (particularly, all of the bus bars 110) may be provided with the information on the cut position.

[0025] (single cell) The cell 1 is a secondary battery. As shown in Fig. 2, the cell 1 includes a battery case 10 and an electrode terminal 20. The cell 1 also includes an electrode body (not shown) and an electrolyte (not shown) inside the battery case 10. The number of cells 1 constituting the battery pack 100 is not particularly specified, and can be changed appropriately depending on the purpose of the battery pack 100 (required power, specifications, etc. of the external device).

[0026] The electrode body is a power generating element housed inside the battery case 10. The structure of the electrode body is not particularly limited, and various structures that can be adopted in general secondary batteries can be adopted without particular limitation. For example, the electrode body can adopt a structure in which a positive electrode and a negative electrode are stacked via a separator. Specific examples of the structure of this type of electrode body include a wound electrode body in which a long strip-shaped positive electrode, a long strip-shaped negative electrode, and a long strip-shaped separator are stacked, and a laminated electrode body in which a rectangular sheet-shaped positive electrode, a rectangular sheet-shaped negative electrode, and a separator are stacked. Note that the detailed structure and materials of each member (positive electrode, negative electrode, and separator) constituting the electrode body can be adopted without particular limitation from those that can be adopted in general secondary batteries (e.g., lithium ion secondary batteries), and do not limit the technology disclosed herein, so detailed explanations are omitted.

[0027] The electrolyte may be a non-aqueous liquid electrolyte (i.e., a non-aqueous electrolyte solution) containing a non-aqueous solvent and a supporting salt, or a solid electrolyte formed by forming a powdered electrolyte into a sheet shape, etc. Note that the specific components of the electrolyte do not limit the technology disclosed herein, and therefore a detailed description thereof will be omitted.

[0028] The battery case 10 is a container that contains the above-mentioned electrode body and electrolyte. As shown in FIG. 2, the battery case 10 is a flat rectangular container. The flat rectangular battery case 10 includes a flat rectangular case body 12 with an open top and a plate-shaped lid body 14 that closes the top opening of the case body 12. The outer shape of the battery case is not limited to the above-mentioned shape, and can be appropriately changed according to the specifications of the external device and the shape of the electrode body. The material of the battery case 10 is not particularly limited as long as it has the required strength. Suitable examples of the material of the battery case 10 include lightweight metal materials with good thermal conductivity (e.g., aluminum, aluminum alloy, stainless steel, nickel-plated steel, etc.).

[0029] As shown in Fig. 1, each of the multiple single cells 1 includes a pair of electrode terminals 20 joined to a bus bar 110. The electrode terminals 20 are attached to a lid 14 of a battery case 10. The electrode terminals 20 are electrically connected to an electrode body inside the battery case 10. Of the pair of electrode terminals 20, one is electrically connected to a positive electrode and the other is electrically connected to a negative electrode inside the battery case 10.

[0030] The battery pack 100 can be used for various purposes, and is preferably used as a power source for driving vehicles such as electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs).

[0031] In the first embodiment, the busbar 110 includes information on the cutting position that does not damage the cells 1, and by reading this information, the cutting position can be accurately determined, and the busbar can be cut with high accuracy so as not to damage the cells 1. Therefore, the busbar 110 can be cut quickly and safely to dismantle the battery pack 100.

[0032] In the battery pack 100, a resin cover (also called a bus bar plate) may be provided between the bus bar 110 and the lid 14 of the battery case 10 from the standpoint of insulating the bus bar 110 from the battery case 10, preventing stress from being applied to the bus bar 110 when it is subjected to an impact, and fixing the position of the bus bar 110 when it is joined. This is shown in a simplified schematic form in Fig. 4. As shown in Fig. 4, the bus bar plate 170 is placed so as to cover the upper surface of the cell 1 (the lid 14 of the battery case 10) while leaving the upper surface of the bus bar 110 exposed.

[0033] On the other hand, from the standpoint of protecting the battery case 10 from impact, the spacer 140 may have a shape with both ends bent or a T-shape, so that the spacer 140 covers the side surface of the battery case 10. This is shown in a simplified schematic diagram in FIG.

[0034] In such a situation, since the cells 1 are hidden by the busbar plate 170 and / or the spacer 140, it is difficult to grasp the cutting position of the cover busbar 110 (i.e., the position between a cell 1 and an adjacent cell 1 in the arrangement direction of the cells 1). Meanwhile, in various forms of the battery pack 100, the top surface of the busbar 110 is most often exposed. For these reasons, it is extremely advantageous to provide information on the cutting position to the busbar 110, as in the first embodiment.

[0035] <Second embodiment> The second embodiment differs from the first embodiment in that while cutting position information is provided on the battery case of the unit cell, a normal bus bar (i.e., a bus bar without cutting position information) is used as the bus bar 110. Explanation of the same points as in the first embodiment will be omitted. In the second embodiment, the cutting position information is provided on the battery case by, for example, pasting, printing, or engraving.

[0036] Fig. 6 is a perspective view of an example of a cell (i.e., a secondary battery) used in the battery pack of the second embodiment. As shown in Fig. 6, the cell 201 includes a flat rectangular battery case 210 including a case body 212 and a lid 214. A sticker 260 including information on the cutting position is attached to the battery case 210 of the cell 201. Specifically, a sticker 260 with a QR code (registered trademark) 250 printed thereon is attached to a side surface along the depth direction Y of the case body 212 of the battery case 210. The sticker 260 is advantageous because the information on the cutting position can be added after the battery pack 100 is completed.

[0037] Furthermore, the position on the side where sticker 260 is attached is a position that is exposed in the form of a battery pack. Since sticker 260 is exposed in the battery pack, information on the cutting position (here, QR code (registered trademark) 250) can be easily read.

[0038] As long as the cutting position information is provided to the battery case 210, the position to which the cutting position information is provided is not limited to this. For example, the cutting position information may be provided (e.g., a sticker is affixed) to the top surface of the battery case 210 (i.e., on the lid 214 of the battery case 210). The position on the top surface of the battery case 210 to which the cutting position information is provided may be between the electrodes 220. Since the top surface of the battery case 210 is exposed in the form of a battery pack, the position to which the sticker 260 is affixed is a position that is exposed in the form of a battery pack. Therefore, in this case as well, it is easy to read the cutting position information (here, QR code (registered trademark) 250).

[0039] In the illustrated example, a QR code (registered trademark) 250 is used as the information on the cutting position, but the content of the information on the cutting position may be another code exemplified in the first embodiment, or an RFID.

[0040] In the assembled battery, the information on the cutting position may be provided to only one unit cell 201, or the information on the cutting position may be provided to a plurality of (particularly, all) unit cells 201.

[0041] In the second embodiment, the battery case 210 contains information on the cutting position that does not damage the cells 201, and by reading this information, the cutting position can be accurately determined, and the bus bar can be cut with high accuracy so as not to damage the cells 201. Therefore, it is possible to quickly and safely cut the bus bar and disassemble the battery pack.

[0042] <Third embodiment> The third embodiment differs from the first embodiment in that a bus bar having a groove at the position to be cut is used instead of the bus bar 110. Therefore, in the third embodiment, the groove is provided in the bus bar, so that information on the cutting position is provided. Explanation of the same points as in the first embodiment will be omitted. Examples of bus bars used in the battery pack of the third embodiment are shown in Figs. 7 and 8.

[0043] Busbar 310 shown in Fig. 7 is flat, and has groove 350 at the position to be cut. The position to be cut is usually the bottom of groove 350. Thus, busbar 310 has a smaller thickness at the portion where groove 350 is formed. There is no particular limit to the depth of groove 350, but from the viewpoint of the strength of busbar 310, it is preferably 50% or less of the thickness of the portion of busbar 310 where groove 350 is not provided. In the form illustrated in Fig. 5, busbar 310 can be easily cut.

[0044] In the bus bar 410 shown in FIG. 8, a groove 450 is provided at the position to be cut by curving a flat plate. The position to be cut is usually the bottom of the groove 450. The thickness of the bus bar 410 is uniform throughout. Therefore, in the embodiment shown in FIG. 8, the bus bar 410 has excellent strength. However, the groove 450 may limit the distance between adjacent cells.

[0045] In the examples shown in Figures 7 and 8, the grooves 350 and 450 have a U-shaped cross-sectional shape, but the cross-sectional shape of the groove is not limited to this. For example, the groove may be V-shaped or inverted trapezoidal. When the groove surface is inclined toward the center of the groove, the groove surface can function as a guide that guides the cutting blade to the cutting position.

[0046] In the battery pack, it is advantageous that all of bus bars 310 and bus bars 410 are provided with information on the cutting positions.

[0047] In the first embodiment, the busbars 310, 410 contain information on the cutting position that will not damage the cells 1, and by reading this information, the cutting position can be accurately determined, and the busbars can be cut with precision so as not to damage the cells. Therefore, it is possible to quickly and safely cut the busbars 310, 410 and dismantle the assembled battery. In particular, in the third embodiment, the cutting position can be accurately determined by visual inspection, and it is easy to apply a cutting blade or the like to the cutting position, which is advantageous when dismantling the assembled battery manually.

[0048] <Other embodiments> In another embodiment, a normal bus bar (i.e., a bus bar without information on the cutting position) is used instead of the bus bar 110 of the first embodiment, the battery pack 100 includes a spacer 140 as an essential component, and information on the cutting position is provided on the side surface or top surface of the spacer 140 along the depth direction Y. If the spacer 140 is made of resin, a code such as a letter code may be formed on the surface of the spacer when the spacer 140 is molded.

[0049] <How to disassemble the battery pack> Next, an embodiment of a method for dismantling a battery assembly disclosed herein will be described in detail with reference to the battery assemblies of the first to third embodiments. The method for dismantling a battery assembly according to this embodiment includes a step (battery assembly preparation step) S101 of preparing a battery assembly in which multiple secondary batteries are electrically connected by a bus bar (here, each of the multiple secondary batteries includes a battery case, and information on the cutting position of the bus bar when dismantling the battery assembly is provided to the battery assembly), a step (cutting position confirmation step) S102, and a step (bus bar cutting step) S103 of cutting the bus bar at the cutting position.

[0050] (Battery pack preparation process S101) In the battery pack preparation step S101, the battery pack described above is prepared as the battery pack. For example, the battery pack according to any one of the first to third embodiments is prepared. The battery pack is typically a used battery, particularly a battery that has been used as an in-vehicle battery, but is not limited to this. For example, it may be an unused battery pack that has been found to be defective before shipping.

[0051] (Cutting position confirmation process S102) The cutting position confirmation step S102 can be performed according to a known method depending on the content of the information on the cutting position that has been given. For example, in the case where a code or RFID including the information on the cutting position has been given as in the first and second embodiments, the code or RFID is read using a reading device such as a reader. In the case where a groove is provided in the busbar as in the third embodiment, the position of the groove is confirmed using a displacement sensor or the like. The position of the groove can also be confirmed visually.

[0052] (Busbar cutting process S103) In the busbar cutting step S103, the busbar can be cut by a known method. For example, the busbar can be cut using a cutting means such as a tool with a cutting blade (e.g., an electric saw), an electric cutting tool (e.g., a grinder, a router), a water cutter, or a laser cutter. From the viewpoint of suppressing heat generation at the cut portion, it is advantageous to use a water cutter. From the viewpoint of higher accuracy, it is advantageous to automatically perform the cutting position confirmation step S102 and the busbar cutting step S103 by connecting a reading device and the cutting means to a computer and linking them.

[0053] According to the method for dismantling a battery pack according to this embodiment, the bus bars can be cut with high precision without damaging the secondary batteries.

[0054] Furthermore, when a groove is provided in the busbar and the surface of the groove is inclined toward the center of the groove as in the above-mentioned third embodiment, it is advantageous to perform the cutting step using a cutting blade, in which the inclined groove surface acts as a guide to guide the cutting blade to the cutting position, thereby improving the cutting accuracy.

[0055] Although the specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above.

[0056] That is, the battery pack and the method for disassembling the battery pack disclosed herein include the following items [1] to

[10] . [1] A plurality of secondary batteries; a bus bar electrically connecting the plurality of secondary batteries, Each of the plurality of secondary batteries includes a battery case; The assembled battery is provided with information on cutting positions of the bus bars when the assembled battery is disassembled. [2] The battery pack according to item [1], wherein the information on the cutting position is attached, printed, or engraved on the bus bar. [3] The battery pack according to item [2], wherein a sticker including information about the cutting positions is attached to the busbar, so that the information about the cutting positions is provided to the busbar. [4] The battery pack according to item [2] or [3], wherein the information on the cutting position is provided on an upper surface of the bus bar. [5] The battery pack according to item [1], wherein the information on the cutting position is attached, printed, or engraved on the battery case. [6] The battery pack according to item [5], wherein the information on the cutting position is provided to the battery case by attaching a sticker containing the information on the cutting position. [7] The battery case has a flat rectangular shape, The battery pack according to item [5] or [6], wherein the information on the cutting positions is provided on a side surface of the battery case along an arrangement direction of the secondary batteries. [8] The battery pack according to item [1], wherein a groove is provided at a cut position of the bus bar, so that information about the cut position is provided. [9] A process for preparing a battery pack in which a plurality of secondary batteries are electrically connected by a bus bar, wherein each of the plurality of secondary batteries has a battery case, and information on the cutting positions of the bus bar when dismantling the battery pack is provided to the battery pack. confirming the cutting position; and cutting the bus bar at the cutting position.

[10] A groove is provided at a cutting position of the bus bar, so that information of the cutting position is provided. The disassembly method according to item

[10] , wherein the cutting step is performed using a cutting blade. [Explanation of symbols]

[0057] 1,201 Secondary battery (single cell) 10 Battery case 12 Case body 14 Lid 20 electrode terminal 100 battery packs 110,310,410 Busbar 150,250 QR Code (registered trademark) 160,260 stickers 350,450 groove

Claims

1. A plurality of secondary batteries; a bus bar electrically connecting the plurality of secondary batteries, Each of the plurality of secondary batteries includes a battery case; The battery pack has information on cutting positions of the bus bars when the battery pack is disassembled, the information being given as a code or an RFID including the information on the cutting positions.

2. The battery pack according to claim 1 , wherein the information on the cutting positions is attached, printed, or engraved on the bus bars.

3. The battery pack according to claim 2 , wherein the information on the cutting positions is provided to the bus bars by attaching a sticker containing the information on the cutting positions.

4. The battery pack according to claim 2 , wherein the information on the cutting position is provided on an upper surface of the bus bar.

5. The battery pack according to claim 1 , wherein the information on the cutting position is attached, printed, or engraved on the battery case.

6. The battery pack according to claim 5 , wherein the information on the cutting position is provided on the battery case by attaching a sticker containing the information on the cutting position.

7. The battery case has a flat rectangular shape, The battery pack according to claim 5 , wherein the information on the cutting positions is provided on a side surface of the battery case along an arrangement direction of the secondary batteries.

8. A step of preparing a battery pack in which a plurality of secondary batteries are electrically connected by a bus bar, wherein each of the plurality of secondary batteries is provided with a battery case, and information on a cutting position of the bus bar when dismantling the battery pack is provided to the battery pack as a code or an RFID including the information on the cutting position. confirming the cutting position by reading the code or the RFID with a reading device; and cutting the bus bar at the cutting position.

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