Battery module

Abstract

The utility model provides a battery module capable of detecting short circuit caused by electrolyte leakage. The battery module includes: a plurality of battery cells stacked in a predetermined direction; a voltage sensor for measuring the voltage of each of the plurality of battery cells; and a flexible substrate disposed between the plurality of battery cells and the voltage sensor, the flexible substrate having: a plurality of wiring parts, one end side of which is connected to the electrodes of the plurality of battery cells and the other end side of which is connected to the voltage sensor; a laminated film that insulates the plurality of wiring portions from each other by sealing the plurality of wiring portions; a plurality of fuses respectively provided in the plurality of wiring portions between the laminated film and the voltage sensor; and a dummy wiring extending from one of the plurality of wiring portions, parallel to the other wiring portions, and not connected to the electrode, the dummy wiring having a fuse provided between the electrode and a portion where the dummy wiring branches in the wiring portions.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a battery module. BACKGROUND

[0002] In Japanese Patent Application Publication No. 2009-140727, a flexible substrate is used as a voltage detection terminal.

[0003] In the configuration disclosed in Japanese Patent Application Publication No. 2009-140727, in the case where a short circuit occurs in a circuit in which a fuse is located on the side of a battery cell (for example, a short circuit between flexible substrates caused by leakage of electrolyte, etc.), there is a risk that the fuse can not be able to suppress the flow of a large current. SUMMARY

[0004] The present utility model is completed in view of the above situation, and aims to provide a battery module capable of detecting a short circuit caused by leakage of electrolyte.

[0005] In the present specification, a battery module disclosed as a first aspect has: a plurality of battery cells stacked in a prescribed direction; voltage sensors that respectively measure voltages of the plurality of battery cells; and a flexible substrate disposed between the plurality of battery cells and the voltage sensors, the flexible substrate having: a plurality of wiring portions, one end side of which is connected to electrodes of the plurality of battery cells, and the other end side of which is connected to the voltage sensors; a laminated film that insulates the plurality of wiring portions from each other by sealing the plurality of wiring portions; a plurality of fuses respectively provided in the plurality of wiring portions between the laminated film and the voltage sensors; and a dummy wiring that branches from one of the plurality of wiring portions, is parallel to other wiring portions, and is not connected to the electrodes, the fuse being provided between the dummy wiring branched in the wiring portion and the electrodes.

[0006] A second aspect is that, in the battery module of the first aspect, the dummy wiring branches from a wiring portion of the plurality of wiring portions that is connected to an electrode of a battery cell having the lowest potential, and is parallel to a wiring portion of the plurality of wiring portions that is connected to an electrode of a battery cell having the highest potential.

[0007] According to the present disclosure, since a short circuit between the dummy wiring and the wiring portion at the time of leakage of electrolyte causes the fuse to be blown and a voltage measurement value to become 0, a short circuit caused by leakage of electrolyte can be detected. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 FIG. 1 is a perspective view showing an example of a configuration of a battery module according to an embodiment.

[0009] Figure 2 FIG. 2 is a side view showing an example of a configuration of the battery module according to the embodiment.

[0010] Figure 3 A schematic diagram for showing a circuit configuration of a battery module according to an embodiment.

[0011] Figure 4 A schematic diagram for showing a case where a short circuit occurs due to leakage of electrolyte of a battery cell in a circuit configuration of a battery module according to an embodiment.

[0012] Figure 5 A schematic diagram for showing a circuit configuration of a modified example 1 of a battery module according to an embodiment.

[0013] Figure 6 A schematic diagram for showing a circuit configuration of a modified example 2 of a battery module according to an embodiment.

[0014] Figure 7 A side view for showing an example of a configuration of a conventional battery module.

[0015] Figure 8 A schematic diagram for showing a circuit configuration of a conventional battery module. DETAILED DESCRIPTION

[0016] A battery module according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components included in the following embodiments are components that can be substituted or are substantially the same by those skilled in the art and easily substituted.

[0017] REFERENCE Figures 1 to 6 A battery module according to an embodiment will be described. The battery module according to the embodiment can be used as a battery for a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), or the like.

[0018] The battery module according to the embodiment is a flow battery such as a lithium-ion secondary battery. As shown in FIG. 1, the battery module 1 has a plurality of battery cells 11, a voltage sensor 12, and a flexible substrate (FPC) 13. Figures 1 to 3

[0019] The battery cell 11 is, for example, a thin battery cell of a bipolar structure. The battery cell 11 is stacked in a prescribed direction. An electrode 111 is provided on a surface of the battery cell 11. The voltage sensor 12 is used to measure the voltage of each of the plurality of battery cells 11.

[0020] ​The flexible substrate 13 is arranged between the plurality of battery cells 11 and the voltage sensor 12. In addition, the flexible substrate 13 has a plurality of wiring portions 131, a laminated film 132, a fuse 133, and a dummy wiring 134.

[0021] One end side of the wiring portion 131 is connected to the electrode 111 of the plurality of battery cells 11, and the other end side is connected to the voltage sensor 12. The wiring portion 131 is composed of, for example, a metal portion (for example, a copper pattern or the like) exposed on the flexible substrate 13. In addition, the one end side of the wiring portion 131 functions as a voltage detection terminal of the voltage sensor 12.

[0022] In addition, as shown in Figure 1 and Figure 2 , the flexible substrate 13 is branched from one substrate, and the branched portions are respectively sandwiched between the battery cells 11. In addition, the wiring portion 131 is provided in the branched portion of the flexible substrate 13, which is not sandwiched between the battery cells 11 (a position close to the branched portion). Figure 1 An arrow on the lower side indicates wiring to the voltage sensor.

[0023] The laminated film 132 insulates the plurality of wiring portions 131 from each other by sealing the plurality of wiring portions 131. In addition, as shown in Figure 2 , the laminated film 132 is provided at a position (a position close to the branched portion) of the flexible substrate 13, which is not sandwiched between the battery cells 11.

[0024] The fuse 133 is provided between the laminated film 132 and the voltage sensor 12 in the plurality of wiring portions 131. The fuse 133 is fused in the case where a short circuit occurs between the battery cells 11. Thus, the voltage measurement value of the voltage sensor 12 becomes 0, and the short circuit is detected.

[0025] The dummy wiring 134 is used to detect liquid leakage of the battery cells 11. The dummy wiring 134 is composed of, for example, a metal portion (for example, a copper pattern or the like) exposed on the flexible substrate 13. In addition, details of the dummy wiring 134 are described later.

[0026] Here, Figure 7 and Figure 8 indicate an example of a configuration of a conventional battery module and a circuit configuration thereof. In the battery module 101, the fuse 133 is also mounted on the flexible substrate 13. However, in the case where a short circuit between the battery cells 11 occurs at a position closer to the battery cells 11 than the fuses 133, the fuses 133 are not fused. In addition, in the battery module 101, in the case where the resistance value at the short circuit position is high, the short circuit current is small, and thus heat is gradually generated. Therefore, in the conventional battery module 101, a short circuit between the battery cells 11 cannot be detected.

[0027] Therefore, in the battery module 1 according to the embodiment, as shown in Figure 3As shown, the above problem is solved by providing the dummy wiring 134 on the flexible substrate 13. The dummy wiring 134 is provided in a manner branching from one of the plurality of wiring portions 131. Further, more specifically, the dummy wiring 134 branches from the wiring portion 131 connected to the battery cell 11 having a lower potential than a site (hereinafter referred to as "leakage detection site") where leakage is to be detected.

[0028] Further, the dummy wiring 134 is provided in parallel (extending in parallel) with the other wiring portions 131. The "other wiring portions 131" means the wiring portions 131 other than the wiring portion 131 from which the dummy wiring 134 branches among the plurality of wiring portions 131. Further, the dummy wiring 134 is apart from the other wiring portions 131 by a prescribed distance and is not connected to the other wiring portions 131. That is, the dummy wiring 134 is provided not to be connected to the electrode 111 of the battery cell 11 and in parallel with the wiring portion 131 connected to the electrode 111.

[0029] For example, in the example of Figure 3 , the dummy wiring 134 branches from the wiring portion 131 among the plurality of wiring portions 131 connected to the electrode 111 of the battery cell 11 having the lowest potential. The "battery cell 11 having the lowest potential" means, for example, the battery cell 11 disposed at the lowermost side in Figure 3 (see the "A" section).

[0030] Further, the dummy wiring 134 is provided in parallel with the wiring portion 131 among the plurality of wiring portions 131 connected to the electrode 111 of the battery cell 11 having the highest potential. The "battery cell 11 having the highest potential" means, for example, the battery cell 11 disposed at the uppermost side in Figure 3 (see the "B" section). By thus providing the dummy wiring 134, it is possible to detect leakage in the "leakage detection site X" shown in Figure 3

[0031] Further, the dummy wiring 134 is in parallel with the wiring portion 131 among the plurality of wiring portions 131 connected to the electrode 111 of the battery cell 11 having the lowest potential and the battery cell 11 having the highest potential. Specifically, the wiring portion 131 is the fourth wiring portion 131 from the top in Figure 3 (see the "C" section). By thus providing the dummy wiring 134, it is possible to detect leakage in the "leakage detection site Y" shown in Figure 3

[0032] Further, in Figure 3 , a fuse 133 is provided between the site (also referred to as the branching site) where the dummy wiring 134 branches among the wiring portions 131 and the battery cell 11 (the electrode 111). Further, the dummy wiring 134 is freely routed depending on the site where leakage is to be detected and is not limited to Figure 3 ​​The wiring shown.

[0033] In the battery module according to the embodiment described above, the dummy wiring 134 is arranged in parallel at a prescribed distance from the other wiring portions 131. In addition, a short circuit circuit composed of the dummy wiring 134 is connected to the wiring portion 131 on the voltage sensor 12 side than each of the fuses 133.

[0034] Thus, in the battery module according to the embodiment, for example Figure 4 As shown, when the electrolyte of the battery cell 11 leaks, the dummy wiring 134 shorts with the wiring portion 131 (the wiring portion 131 extending in parallel with the dummy wiring 134). Then, a short circuit current flows through the wiring portion 131 of the branch source of the dummy wiring 134 via the dummy wiring 134, and the fuse 133 is melted. As a result, since the voltage measurement value of the voltage sensor 12 is 0, it is possible to detect a short circuit (an abnormality) caused by the leakage of the electrolyte.

[0035] In addition, in the battery module according to the embodiment, as described above, the dummy wiring 134 is arranged to branch from the wiring portion 131 connected to the battery cell 11 having the lowest potential and to be in parallel with the wiring portion 131 connected to the battery cell 11 having the highest potential. Thus, the voltage difference is the largest, and the short circuit current at the time of the leakage of the electrolyte of the battery cell 11 is the largest, so it is possible to more reliably melt the fuse 133.

[0036] In addition, in the battery module according to the embodiment, it is possible to freely set the positions of the fuses 133, so the design freedom of the circuit is improved. In addition, in the battery module according to the embodiment, it is not necessary to additionally prepare a sensor for leakage detection, so it is possible to achieve the leakage detection in a small and space-saving manner.

[0037] A first modification of the battery module according to the embodiment will be described below with reference to Figure 5 The battery module 1A according to the first modification has a plurality of battery cells 11, a voltage sensor 12, and a flexible substrate 13. In addition, the flexible substrate 13 has four dummy wirings 134A instead of the dummy wiring 134 of the battery module 1 according to the embodiment. The dummy wirings 134A are arranged in parallel with the four wiring portions 131, respectively. Thus, in the battery module 1A, four leakage detection sites are set. Figure 3

[0038] As shown in FIG. 6, the battery module 1B according to the second modification has a plurality of battery cells 11, a voltage sensor 12, and a flexible substrate 13. In addition, the flexible substrate 13 has two dummy wirings 134B instead of the dummy wiring 134 of the battery module 1 according to the embodiment. The dummy wirings 134B are arranged in parallel with the two wiring portions 131, respectively. Thus, in the battery module 1B, two leakage detection sites are set. Figure 5 ​As shown, the leakage detection point of the dummy wiring 134A can be arbitrarily set. For example, it can be set at a precise point in a location prone to leakage, or it can be set to the amount of all battery cells when the location prone to leakage is unknown. In addition, similar to the battery module 1 described above, in order to reliably blow the fuse 133, it is preferable to set the branch of the dummy wiring 134A to the wiring section 131 with the lowest potential, so that the dummy wiring 134A, which serves as the leakage detection point, runs parallel to the wiring section 131 with the highest potential.

[0039] For variation 2 of the battery module involved in the implementation method, refer to the following. Figure 6 The following explanation is provided. The battery module 1B involved in Modification 2 includes multiple battery cells 11, a voltage sensor 12, and a flexible substrate 13. Furthermore, the flexible substrate 13 has two independent dummy wirings 134B instead of... Figure 3 The dummy wiring 134B branches off from different wiring sections 131 (see "Branch Sections" in the diagram). Furthermore, these dummy wirings 134B are configured to run parallel to the two wiring sections 131. Thus, two leakage detection points are established in the battery module 1B.

[0040] like Figure 6 As shown, the leakage detection portion of the dummy wiring 134B can be arbitrarily set. For example, as shown in the figure, in order to prevent the short-circuit current from being too large during a short circuit, it is also possible to branch from the short-circuit portion formed by several battery cells. In addition, similar to the battery module 1 described above, in order to reliably blow the fuse 133, it is preferable to set the branch portion of the dummy wiring 134B as the wiring portion 131 with the lowest potential, and to make the dummy wiring 134B, which serves as the leakage detection portion, run parallel to the wiring portion 131 with the highest potential.

[0041] Those skilled in the art can readily derive further effects and variations. Therefore, the broader aspects of this invention are not limited to the specific details and representative embodiments shown and described above. Consequently, various changes can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Claims

1. A battery module, characterized by, Having: a plurality of battery cells stacked in a prescribed direction; voltage sensors that respectively measure voltages of the plurality of battery cells; and a flexible substrate disposed between the plurality of battery cells and the voltage sensors, the flexible substrate having: a plurality of wiring portions that are connected at one end side to electrodes of the plurality of battery cells and at the other end side to the voltage sensors; a laminated film that insulates the plurality of wiring portions from each other by sealing the plurality of wiring portions; a plurality of fuses respectively provided in the plurality of wiring portions between the laminated film and the voltage sensors; and a dummy wiring that branches from one of the plurality of wiring portions, runs in parallel with the other wiring portions, and is not connected to the electrodes, the fuse being provided between the portion of the wiring portion from which the dummy wiring branches and the electrodes. The dummy wiring branches from the wiring portion connected to the electrode of the battery cell having the lowest potential among the plurality of battery cells and runs in parallel with the wiring portion connected to the electrode of the battery cell having the highest potential among the plurality of battery cells.

2. The battery module of claim 1, wherein, ​

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