Battery module

Abstract

To provide a battery module that can detect short-circuiting due to leak of an electrolyte solution.SOLUTION: A battery module includes a plurality of battery cells stacked in a predetermined direction, a voltage sensor that measures the voltage of each of the battery cells, and a flexible substrate disposed between the battery cells and the voltage sensor. The flexible substrate includes a plurality of wiring parts with one end side connected to electrodes of the battery cells and the other end side connected to the voltage sensor, a laminate film that insulates the wiring parts from each other by sealing the wiring parts, a fuse provided between the laminate film and the voltage sensor in each of the wiring parts, and a dummy wire branched from at least one wiring part of the wiring parts, provided in parallel to the other wiring parts, and not connected to the electrode. The fuse exists between the electrode and the place where the dummy wire is branched in the wiring part.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses using a flexible printed circuit board as a voltage detection terminal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration disclosed in Patent Document 1, when a short circuit (such as a short circuit between flexible printed circuit boards due to leakage of electrolytic solution) occurs in a circuit located closer to the battery cell side than the fuse, there is a risk that a large current cannot be suppressed by the fuse.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a battery module capable of detecting a short circuit due to leakage of electrolytic solution.

Means for Solving the Problems

[0006] The battery module according to the present disclosure includes a plurality of battery cells stacked in a predetermined direction, a voltage sensor that measures 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. One end of the flexible substrate is connected to the electrodes of the plurality of battery cells, and the other end is connected to the voltage sensor. The flexible substrate includes a plurality of wiring portions, a laminate film that seals the plurality of wiring portions to insulate the plurality of wiring portions from each other, fuses provided between the laminate film and the voltage sensor in the plurality of wiring portions, and a dummy wiring that branches from one of the plurality of wiring portions and runs parallel to another wiring portion and is not connected to the electrode. A fuse is provided between the location where the dummy wiring branches in the wiring portion and the electrode.

Advantages of the Invention

[0007] According to the present disclosure, when the electrolyte leaks, the dummy wiring and the wiring portion are short-circuited, causing the fuse to blow and the voltage measurement value to become 0. Therefore, a short circuit due to the leakage of the electrolyte can be detected.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

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Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0009] The battery module according to the embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that can be easily replaced by those skilled in the art or are substantially the same.

[0010] The battery module according to the embodiment will be described with reference to FIGS. 1 to 6. The battery module according to the embodiment is used as a battery for, for example, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), etc.

[0011] The battery module according to the embodiment is a liquid-based battery such as a lithium-ion secondary battery. As shown in FIGS. 1 to 3, this battery module 1 includes a plurality of battery cells 11, a voltage sensor 12, and a flexible printed circuit (FPC) 13.

[0012] The battery cell 11 is, for example, a thin battery cell having a bipolar structure. The battery cells 11 are stacked in a predetermined direction. An electrode 111 is provided on the surface of the battery cell 11. The voltage sensor 12 is for measuring the voltages of the plurality of battery cells 11 respectively.

[0013] The flexible printed circuit 13 is disposed between the plurality of battery cells 11 and the voltage sensor 12. The flexible printed circuit 13 includes a plurality of wiring portions 131, a laminate film 132, a fuse 133, and a dummy wiring 134.

[0014] One end of the wiring portion 131 is connected to the electrodes 111 of the plurality of battery cells 11, and the other end is connected to the voltage sensor 12. This wiring portion 131 is composed of, for example, a metal portion (such as a copper pattern etc.) exposed on the flexible substrate 13. Also, one end side of the wiring portion 131 functions as a voltage detection terminal of the voltage sensor 12.

[0015] Note that, as shown in FIGS. 1 and 2, the flexible substrate 13 branches off from a single substrate, and these branched portions are respectively sandwiched between the battery cells 11. Also, wiring portions 131 are respectively provided at the branched portions of this flexible substrate 13.

[0016] The laminate film 132 insulates the plurality of wiring portions 131 from each other by sealing the plurality of wiring portions 131. Also, as shown in FIG. 2, the laminate film 132 is provided at a position where it is not sandwiched between the battery cells 11 (a position where the branched portions approach) at the branched portion of the flexible substrate 13.

[0017] The fuses 133 are respectively provided between the laminate film 132 and the voltage sensor 12 in the plurality of wiring portions 131. These fuses 133 blow when a short circuit occurs between the battery cells 11. Thereby, the voltage measurement value of the voltage sensor 12 becomes 0, and the short circuit is detected.

[0018] The dummy wiring 134 is for detecting the leakage of the battery cells 11. This dummy wiring 134 is composed of, for example, a metal portion (such as a copper pattern etc.) exposed on the flexible substrate 13. Note that the details of the dummy wiring 134 will be described later.

[0019] Here, FIGS. 7 and 8 show an example of the configuration of a conventional battery module and its circuit structure. Also in this battery module 101, a fuse 133 is mounted on the flexible substrate 13. However, when a short circuit occurs between the battery cells 11 on the side closer to the battery cells 11 than these fuses 133, the fuses 133 do not blow. Further, in the battery module 101, when the resistance value of the short-circuited portion is high, since the short-circuit current is small, heat is generated little by little. Therefore, in the conventional battery module 101, a short circuit between the battery cells 11 could not be detected.

[0020] Therefore, in the battery module 1 according to the embodiment, as shown in FIG. 3, by providing a dummy wiring 134 on the flexible substrate 13, the above problem is solved. This dummy wiring 134 is provided so as to branch from one of the plurality of wiring portions 131. More specifically, the dummy wiring 134 branches from a wiring portion 131 connected to a battery cell 11 having a lower potential than the location where liquid leakage is to be detected (hereinafter referred to as the "liquid leakage detection location").

[0021] Further, the dummy wiring 134 is provided so as to run parallel to the other wiring portions 131. "The other wiring portions 131" refers to the wiring portions 131 other than the wiring portion 131 that is the branch source of the dummy wiring 134 among the plurality of wiring portions 131. Also, the dummy wiring 134 is separated from the other parallel-running wiring portions 131 by a predetermined distance and is not connected to the other wiring portions 131. That is, the dummy wiring 134 is not connected to the electrode 111 of the battery cell 11 and is provided so as to run parallel to the wiring portion 131 connected to the electrode 111.

[0022] For example, in the example of FIG. 3, the dummy wiring 134 branches from a wiring portion 131 connected to the electrode 111 of the battery cell 11 having the lowest potential among the plurality of wiring portions 131. "The battery cell 11 having the lowest potential" refers to, for example, the battery cell 11 disposed at the lowermost side in the same figure (see part A).

[0023] Further, the dummy wiring 134 is provided so as to run parallel to the wiring portion 131 connected to the electrode 111 of the battery cell 11 having the highest potential among the plurality of wiring portions 131. The "battery cell 11 having the highest potential" refers to, for example, the battery cell 11 arranged at the uppermost side in the same figure (see part B). By providing the dummy wiring 134 in this way, it is possible to detect the leakage at the "leakage detection location X" shown in FIG. 3.

[0024] Further, the dummy wiring 134 is provided so as to run parallel to the wiring portion 131 connected to the electrode 111 of the battery cell 11 between the battery cell 11 having the lowest potential and the battery cell 11 having the highest potential among the plurality of wiring portions 131. Specifically, this wiring portion 131 is the fourth wiring portion 131 from the top in FIG. 3. By providing the dummy wiring 134 in this way, it is possible to detect the leakage at the "leakage detection location Y" shown in the same figure.

[0025] Furthermore, in FIG. 3, a fuse 133 is provided between the location where the dummy wiring 134 branches in the wiring portion 131 (branch location) and the battery cell 11 (electrode 111). The dummy wiring 134 may be freely wired according to the location where leakage is to be detected, and is not limited to that shown in FIG. 3.

[0026] In the battery module according to the embodiment described above, the dummy wiring 134 is provided so as to be separated from the other wiring portions 131 by a predetermined distance and run parallel. Also, the short - circuit circuit constituted by this dummy wiring 134 is connected to the wiring portion 131 on the voltage sensor 12 side with respect to each fuse 133.

[0027] Thus, in the battery module according to the embodiment, for example, as shown in FIG. 4, when the electrolytic solution of the battery cell 11 leaks, the dummy wiring 134 and the wiring portion 131 (the wiring portion 131 running parallel to the dummy wiring 134) are short-circuited. Then, via the dummy wiring 134, a short-circuit current flows to the wiring portion 131 where the dummy wiring 134 branches, and the fuse 133 blows. As a result, since the voltage measurement value by the voltage sensor 12 becomes 0, a short circuit (abnormality) due to the leakage of the electrolytic solution can be detected.

[0028] Also, in the battery module according to the embodiment, as described above, the dummy wiring 134 is provided so as to branch from the wiring portion 131 connected to the battery cell 11 with the lowest potential and run parallel to the wiring portion 131 connected to the battery cell 11 with the highest potential. Thereby, the voltage difference becomes maximum, and the short-circuit current when the electrolytic solution of the battery cell 11 leaks becomes maximum, so that the fuse 133 can be blown more reliably.

[0029] In addition, in the battery module according to the embodiment, since the position of the fuse 133 can be freely set, the degree of freedom in circuit design is improved. Further, in the battery module according to the embodiment, since there is no need to separately prepare a sensor for detecting liquid leakage, it is possible to realize liquid leakage detection in a small size and with less space.

[0030] (Modification Example 1) A modification example 1 of the battery module according to the embodiment will be described with reference to FIG. 5. The battery module 1A according to the modification example 1 includes a plurality of battery cells 11, a voltage sensor 12, and a flexible substrate 13. Further, the flexible substrate 13 includes four dummy wirings 134A instead of the dummy wiring 134 in FIG. 3. These dummy wirings 134A are provided so as to run parallel to the four wiring portions 131 respectively. Thereby, in the battery module 1A, four liquid leakage detection locations are set.

[0031] As shown in FIG. 5, the liquid leakage detection location of the dummy wiring 134A can be arbitrarily set. For example, it may be set pinpointedly at a location where liquid leakage is likely to occur, or if the location where liquid leakage is likely to occur is unknown, it may be set for all cells. Also, similar to the battery module 1 described above, in order to surely blow the fuse 133, the branch location of the dummy wiring 134A is set as the wiring part 131 with the lowest potential, and it is preferable that the dummy wiring 134A serving as the liquid leakage detection location runs parallel to the wiring part 131 with the highest potential.

[0032] (Modification 2) A modification 2 of the battery module according to the embodiment will be described with reference to FIG. 6. The battery module 1B according to the modification 2 includes a plurality of battery cells 11, a voltage sensor 12, and a flexible substrate 13. Further, the flexible substrate 13 includes two independent dummy wirings 134B instead of the dummy wiring 134 in FIG. 3. These dummy wirings 134B branch from different wiring parts 131 (see "branch location"). Also, these dummy wirings 134B are provided so as to run parallel to the two wiring parts 131 respectively. Thereby, in the battery module 1B, two liquid leakage detection locations are set.

[0033] As shown in FIG. 6, the liquid leakage detection location of the dummy wiring 134B can be arbitrarily set. For example, as shown in the figure, it may branch from a location where a short circuit occurs for several cells so that the short circuit current during a short circuit does not become too large. Also, similar to the battery module 1 described above, in order to surely blow the fuse 133, the branch location of the dummy wiring 134B is set as the wiring part 131 with the lowest potential, and it is preferable that the dummy wiring 134B serving as the liquid leakage detection location runs parallel to the wiring part 131 with the highest potential.

[0034] Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Signs

[0035] 1, 1A, 1B, 101 Battery module 11 Battery cell 111 Electrode 12 Voltage sensor 13 Flexible printed circuit (FPC) 131 Wiring part 132 Laminate film 133 Fuse 134, 134A, 134BDummy wiring

Claims

1. a plurality of battery cells stacked in a predetermined direction; a voltage sensor that measures the voltage of each of the plurality of battery cells; a flexible substrate disposed between the plurality of battery cells and the voltage sensor; comprising; the flexible substrate includes; a plurality of wiring portions having one end connected to the electrodes of the plurality of battery cells and the other end connected to the voltage sensor; a laminate film that seals the plurality of wiring portions to insulate the plurality of wiring portions from each other; fuses respectively provided between the laminate film and the voltage sensor in the plurality of wiring portions; a dummy wiring that branches from one of the plurality of wiring portions, is provided to run parallel to another wiring portion, and is not connected to the electrode; comprising; a fuse is provided between a location where the dummy wiring branches in the wiring portion and the electrode; a battery module.

2. the dummy wiring; branches from a wiring portion connected to an electrode of a battery cell having the lowest potential among the wiring portions; is provided to run parallel to a wiring portion connected to an electrode of a battery cell having the highest potential among the wiring portions; The battery module according to claim 1.

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