Leakage detection system and laminated cell module

Abstract

To provide a liquid leakage detection system and a stacked cell module that are capable of preventing liquid junction from occurring between voltage detection terminals of respective cells.SOLUTION: The liquid leakage detection system includes: a stacked cell module including a plurality of cells stacked along a gravity direction; a connector electrically connected to the cell; and a processor configured to determine whether the stacked cell module is leaking, based on an electrical signal input from the connector. The cell includes: a plate-shaped secondary battery; a sealing portion that stores the cell and seals an outer periphery of the cell; a voltage detection terminal having one end electrically connected to a cathode or an anode of the secondary battery and the other end exposed to an outside of the sealing portion; and a liquid leakage detection terminal that is electrically insulated from the secondary battery and the voltage detection terminal, is located directly below the voltage detection terminal, and is fixed to the sealing portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a liquid leakage detection system and a stacked cell module.

Background Art

[0002] Patent Document 1 discloses a technique of arranging a liquid leakage sensor in a liquid leakage retention region which is a portion where the electrolytic solution tends to stay when the electrolytic solution leaks from a battery cell.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When each cell has a voltage detection terminal for detecting the voltage in each cell, in the configuration of Patent Document 1, a liquid junction may occur between the voltage detection terminals of each cell before the liquid leakage is detected by the liquid leakage sensor.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a liquid leakage detection system and a stacked cell module capable of preventing a liquid junction from occurring between the voltage detection terminals of each cell.

Means for Solving the Problems

[0006] The liquid leakage detection system according to the present disclosure includes a stacked cell module including a plurality of cells stacked along the gravitational direction, a connector electrically connected to the cells, and a processor configured to determine whether the stacked cell module is leaking liquid based on an electrical signal input from the connector. The cell includes a plate-shaped secondary battery, a sealing portion that stores the cell and seals the outer periphery of the cell, a voltage detection terminal having one end electrically connected to the positive electrode or the negative electrode of the secondary battery and the other end exposed outside the sealing portion, and a liquid leakage detection terminal that is electrically insulated from the secondary battery and the voltage detection terminal, is located directly below the voltage detection terminal, and is fixed to the sealing portion. The connector includes a liquid leakage detection terminal connection portion to which the liquid leakage detection terminal is electrically connected. The processor determines whether the voltage detection terminal and the liquid leakage detection terminal are in liquid contact based on an electrical signal input from the liquid leakage detection terminal connection portion.

[0007] The stacked cell module according to the present disclosure is a stacked cell module including a plurality of cells stacked along the gravitational direction. The cell includes a plate-shaped secondary battery, a sealing portion that stores the cell and seals the outer periphery of the cell, a voltage detection terminal having one end electrically connected to the positive electrode or the negative electrode of the secondary battery and the other end exposed outside the sealing portion, and a liquid leakage detection terminal that is electrically insulated from the secondary battery and the voltage detection terminal, is located directly below the voltage detection terminal, and is fixed to the sealing portion.

Effects of the Invention

[0008] According to the present disclosure, it is possible to realize a liquid leakage detection system and a stacked cell module that can prevent liquid contact from occurring between the voltage detection terminals of each cell.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] The liquid leakage detection system and the stacked cell module according to the embodiments 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 replaced and are easy for those skilled in the art, or those that are substantially the same.

[0011] (Embodiment 1) 〔Configuration of the Liquid Leakage Detection System〕 The liquid leakage detection system includes the stacked cell module 1 shown in FIGS. 1 and 2, the connector 2 shown in FIGS. 3 and 4, and the liquid leakage determination unit 3 shown in FIG. 4. The stacked cell module 1 includes a plurality of cells stacked along the gravitational direction. The connector 2 is electrically connected to the cells of the stacked cell module 1. The liquid leakage determination unit 3 determines whether the stacked cell module 1 is leaking liquid based on the electrical signal input from the connector 2.

[0012] 〔Configuration of the Stacked Cell Module〕 FIG. 1 is a configuration diagram of the stacked cell module according to Embodiment 1. As shown in FIG. 1, the stacked cell module 1 includes a plurality of cells 10 stacked along the gravitational direction.

[0013] Figure 2 is a cross-sectional view corresponding to the line A-A in Figure 1. As shown in Figure 2, each cell 10 includes a secondary battery 11, a sealing portion 12, an output surface 13, a voltage detection terminal 14, and a leakage detection terminal 15.

[0014] The secondary battery 11, for example, has a plate shape and is laminated along the gravitational direction in a bipolar structure. The secondary battery 11 is coated on a copper foil or an aluminum foil forming the output surface 13, and includes a positive electrode and a negative electrode arranged to face each other, a resin frame forming the sealing portion 12, an electrolytic solution filled inside the resin frame, and a separator arranged inside the resin frame and electrically insulating between the positive electrode and the negative electrode.

[0015] The sealing portion 12 houses the cell and seals the outer periphery of the cell. The sealing portion 12 has insulating properties and is made of, for example, resin.

[0016] The output surface 13 outputs the power of the secondary battery 11. By stacking a plurality of cells 10 such that the output surfaces 13 of the respective cells 10 are in contact with each other, the plurality of cells 10 are connected in series to form a laminated cell module 1 having a bipolar structure. Since the laminated cell module 1 has a bipolar structure, it is possible to form a high-voltage battery cell.

[0017] One end of the voltage detection terminal 14 is electrically connected to the positive electrode or the negative electrode of the secondary battery 11, and the other end is exposed outside the sealing portion 12. The voltage detection terminals 14 of the respective cells 10 are arranged at different positions in the horizontal direction. Although Figure 2 shows an example in which the voltage detection terminals 14 of the respective cells 10 are arranged in a stepped manner, they may be arranged at different positions in the horizontal direction.

[0018] The leakage detection terminal 15 is electrically insulated from the secondary battery 11 and the voltage detection terminal 14, is located directly below the voltage detection terminal 14, and is fixed to the sealing portion 12. The leakage detection terminal 15 may be embedded in the sealing portion 12 or may be adhered to the surface of the sealing portion 12.

[0019] 〔Configuration of Connector〕 Figure 3 is a configuration diagram of the connector. As shown in Figure 3, the connector 2 includes a voltage detection terminal connection portion 21 and a liquid leakage detection terminal connection portion 22.

[0020] The voltage detection terminal 14 is electrically connected to the voltage detection terminal connection portion 21.

[0021] The liquid leakage detection terminal 15 is electrically connected to the liquid leakage detection terminal connection portion 22.

[0022] 〔Configuration of the liquid leakage determination unit〕 The liquid leakage determination unit 3 is, for example, a personal computer, and includes a processor composed of a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field-Programmable Gate Array), etc., and a memory (main storage unit) composed of a RAM (Random Access Memory), a ROM (Read Only Memory), etc.

[0023] Based on the electrical signals input from the voltage detection terminal connection portion 21 and the liquid leakage detection terminal connection portion 22, the liquid leakage determination unit 3 determines whether or not the voltage detection terminal 14 and the liquid leakage detection terminal 15 are in liquid contact.

[0024] Figure 4 is a block diagram of the connector and the liquid leakage determination unit. As shown in Figure 4, the liquid leakage determination unit 3 includes a voltage detection unit 31, a liquid leakage detection unit 32, a voltage calculation unit 33, and a liquid leakage determination unit 34.

[0025] An electrical signal from the voltage detection terminal connection portion 21 is input to the voltage detection unit 31.

[0026] An electrical signal from the liquid leakage detection terminal connection portion 22 is input to the liquid leakage detection unit 32.

[0027] The voltage calculation unit 33 calculates the voltage at the voltage detection terminal 14 based on the electrical signal from the voltage detection terminal connection unit 21 input via the voltage detection unit 31. Further, the voltage calculation unit 33 calculates the voltage at the liquid leakage detection terminal 15 based on the electrical signal from the liquid leakage detection terminal connection unit 22 input via the liquid leakage detection unit 32.

[0028] The liquid leakage determination unit 34 determines whether each cell 10 is leaking using the voltage of the liquid leakage detection terminal 15. When there is no liquid leakage from the interface between the sealing portion 12 and the voltage detection terminal 14, no voltage is applied to the liquid leakage detection terminal 15 from the outside. Therefore, the liquid leakage determination unit 34 determines that there is no liquid leakage if the voltage of the liquid leakage detection terminal 15 calculated by the voltage calculation unit 33 is the release voltage. On the other hand, when the electrolytic solution of the secondary battery 11 is leaking from the interface between the sealing portion 12 and the voltage detection terminal 14, the leaked electrolytic solution drips downward due to gravity and reaches the liquid leakage detection terminal 15 located directly below, and then the voltage from the secondary battery 11 is applied to the liquid leakage detection terminal 15. Therefore, the liquid leakage determination unit 34 determines that there is liquid leakage if the voltage of the liquid leakage detection terminal 15 calculated by the voltage calculation unit 33 is not the release voltage but the actual voltage.

[0029] According to the first embodiment described above, since each cell 10 of the stacked cell module 1 is provided with the liquid leakage detection terminal 15 located directly below the voltage detection terminal 14, when liquid leaks from the interface between the sealing portion 12 and the voltage detection terminal 14, the leaked electrolytic solution immediately reaches the liquid leakage detection terminal 15 located directly below. As a result, it is possible to detect the liquid leakage of each cell 10 before a liquid bridge occurs between the voltage detection terminals 14 of each cell 10, and it is possible to prevent a liquid bridge from occurring between the voltage detection terminals 14 of each cell 10.

[0030] Further, in each cell 10 of the stacked cell module 1, since the voltage detection terminals 14 are arranged at different positions in the horizontal direction from each other, the stacked cell module 1 is configured such that it is difficult for a liquid bridge to occur between the voltage detection terminals 14 of each cell 10.

[0031] In addition, when the liquid leakage determination unit 3 uses an external low-voltage source as the power supply instead of the high voltage of the stacked cell module 1, the high voltage and the low voltage are in a normally insulated or high-resistance connection state, and the liquid leakage determination unit 3 may determine liquid leakage by detecting that the high voltage and the low voltage are short-circuited or resistively short-circuited.

[0032] (Modification Example 1) FIG. 5 is a configuration diagram of a stacked cell module according to Modification Example 1. As shown in FIG. 5, in the stacked cell module 1A, the liquid leakage detection terminals 15A of the respective cells 10 are integrally configured and electrically connected to each other. In this case, the shape of the liquid leakage detection terminal connection portion of the connector also needs to be a shape corresponding to the liquid leakage detection terminal 15A. Thus, by integrally configuring the liquid leakage detection terminals 15A, the wiring connecting the liquid leakage detection terminal connection portion 22 and the liquid leakage detection portion 32 can be combined into one, so that the configuration can be simplified.

[0033] (Modification Example 2) FIG. 6 is a block diagram of a connector and a liquid leakage determination unit according to Modification Example 2. As shown in FIG. 6, the liquid leakage determination unit 3B includes a liquid leakage determination unit 34B and a liquid leakage detection unit 35B.

[0034] The liquid leakage detection unit 35B detects whether there is a leakage current in the stacked cell module 1 based on the electrical signal from the liquid leakage detection terminal connection portion 22 input via the liquid leakage detection portion 32.

[0035] When the liquid leakage detection unit 35B detects that there is a leakage current in the stacked cell module 1, the liquid leakage determination unit 34B determines that the stacked cell module 1 is leaking liquid.

[0036] According to the liquid leakage determination unit 3B, since the voltage calculation unit 33 does not need to calculate the voltage at the liquid leakage detection terminal 15, it is possible to easily determine whether the stacked cell module 1 is leaking liquid while reducing the processing load of the liquid leakage determination unit 3B.

[0037] (Modification Example 3) FIG. 7 is a configuration diagram of a connector according to Modification 3. As shown in FIG. 7, the connector 2C includes a connection circuit 23C that electrically connects each liquid leakage detection terminal connection portion 22. In this way, by electrically connecting each liquid leakage detection terminal connection portion 22, the wiring connecting the liquid leakage detection terminal connection portion 22 and the liquid leakage detection portion 32 can be combined into one, so that the configuration can be simplified.

[0038] 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 represented and described as 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 Reference Numerals

[0039] 1, 1A Stacked cell module 2, 2C Connector 3, 3B Liquid leakage determination unit 10 Cell 11 Secondary battery 12 Sealing portion 13 Output surface 14 Voltage detection terminal 15, 15A Liquid leakage detection terminal 21 Voltage detection terminal connection portion 22 Liquid leakage detection terminal connection portion 23C Connection circuit 31 Voltage detection unit 32 Liquid leakage detection unit 33 Voltage calculation unit 34, 34B Liquid leakage determination unit 35B Liquid leakage detection unit

Claims

1. A stacked cell module including a plurality of cells stacked along the direction of gravity, A connector electrically connected to the cell, A processor configured to determine whether the stacked cell module is leaking liquid based on an electrical signal input from the connector, A liquid leakage determination system comprising: The cell is A plate-shaped secondary battery, A sealing portion that stores the secondary battery and seals the outer periphery of the secondary battery, A voltage detection terminal having one end electrically connected to the positive electrode or negative electrode of the secondary battery and the other end exposed outside the sealing portion, A liquid leakage detection terminal that is electrically insulated from the secondary battery and the voltage detection terminal, is located directly below the voltage detection terminal, and is fixed to the sealing portion, And comprising The connector is A liquid leakage detection terminal connection portion to which the liquid leakage detection terminal is electrically connected, And comprising The processor is Based on an electrical signal input from the liquid leakage detection terminal connection portion, to determine whether the voltage detection terminal and the liquid leakage detection terminal are in liquid contact Liquid leakage detection system.

2. The liquid leakage detection system according to claim 1, wherein the liquid leakage detection terminals are electrically connected to each other.

3. The liquid leakage detection system according to claim 1, wherein the voltage detection terminals are arranged at different positions in the horizontal direction from each other.

4. The liquid leakage detection system according to claim 1, wherein the secondary batteries are stacked in a bipolar structure.

5. A stacked cell module including a plurality of cells stacked along the direction of gravity, The cell is A plate-shaped secondary battery, a sealing portion that stores the secondary battery and seals the outer periphery of the secondary battery, a voltage detection terminal having one end electrically connected to the positive electrode or the negative electrode of the secondary battery and the other end exposed outside the sealing portion, a liquid leakage detection terminal that is electrically insulated from the secondary battery and the voltage detection terminal, is located directly below the voltage detection terminal, and is fixed to the sealing portion, and a laminated cell module including the same.

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