Battery pack

Abstract

To suppress increase in a thickness of a spacer where temperature sensors are provided, when individually measuring a temperature of a plurality of laminated cell modules.SOLUTION: A battery pack comprises first and second cell modules, a spacer, and first and second temperature sensors. The first cell module includes a laminate of a plurality of unit cells. The second cell module is laminated on the first cell module. The second cell module includes a laminate of a plurality of unit cells. The first temperature sensor is provided in the spacer. The first temperature sensor measures a temperature of the first cell module. The second temperature sensor is provided in the spacer. The second temperature sensor measures a temperature of the second cell module. The first and second temperature sensors are arranged in parallel to each other along a plane direction of the spacer.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a battery pack including a cell module including a laminate of a plurality of single cells.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2015-138649 discloses a battery pack provided with a pressure sensor between two adjacent single cells in order to detect bulging deformation of a single cell. This conventional battery pack includes a spacer provided between two adjacent single cells. The pressure sensor is attached to the central portion of this spacer. The pressure sensor is provided for each single cell. Therefore, according to this conventional battery pack, it is possible to individually detect bulging deformation of all single cells.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Consider a battery pack in which a plurality of cell modules each including a plurality of stacked single cells are stacked. Further, consider individually detecting the temperatures of the plurality of cell modules in this battery pack. In this case, it is necessary to provide two temperature sensors for individually measuring the temperatures of two adjacent cell modules on the spacer. However, when these two temperature sensors are arranged in the stacking direction of the cell modules, the thickness of the spacer increases according to the heights of the two temperature sensors in the stacking direction. Therefore, development for suppressing an increase in the thickness of the spacer provided with the temperature sensors is required.

[0005] One object of the present invention is to provide a technique capable of suppressing an increase in the thickness of a spacer provided with a temperature sensor when individually measuring the temperatures of a plurality of stacked cell modules.

Means for Solving the Problem

[0006] The present invention is a battery pack and has the following characteristics. The battery pack includes first and second cell modules, a spacer, and first and second temperature sensors. The first cell module includes a stack of a plurality of single cells. The second cell module is laminated on the first cell module. The second cell module includes a stack of a plurality of single cells. The first temperature sensor is provided on the spacer. The first temperature sensor measures the temperature of the first cell module. The second temperature sensor is provided on the spacer. The second temperature sensor measures the temperature of the second cell module. The first and second temperature sensors are arranged in parallel along the plane direction of the spacer.

[0007] In the present invention, the spacer may include first and second slits formed in the plane direction. The first temperature sensor may be disposed in the first slit. The second temperature sensor may be disposed in the second slit.

[0008] In the present invention, the spacer may include a slit formed in the plane direction. The first and second temperature sensors may be arranged in pairs in the slit.

Advantages of the Invention

[0009] According to the present invention, the first and second temperature sensors are arranged in parallel along the plane direction of the spacer. Therefore, it is possible to make the substantial thickness of the spacer equivalent to the thicknesses of the first and second temperature sensors. Therefore, when measuring the temperatures of a plurality of laminated cell modules individually, it is possible to suppress an increase in the thickness of the spacer 2.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0011] Hereinafter, with reference to the drawings, the assembled battery according to the embodiment of the present invention will be described. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

[0012] 1. Configuration Example of Assembled Battery The assembled battery according to the embodiment is a secondary battery mounted on a moving body such as an electric vehicle that travels using a motor as a drive source. FIG. 1 is a diagram showing an overall configuration example of the assembled battery according to the embodiment. As shown in FIG. 1, the assembled battery B according to the embodiment includes a cell module 1, a spacer 2, and a current collector plate 3.

[0013] In the example shown in FIG. 1, four cell modules 1 are stacked. Each cell module 1 includes a laminate in which a plurality of "single cells" are stacked. The configuration of the "single cell" will be described later. A total of three layers of spacers 2 are provided. These spacers 2 are provided between two adjacent cell modules 1. Two layers of current collector plates 3 are provided, one for the positive electrode and one for the negative electrode. The current collector plate 3 for the positive electrode is located, for example, above the cell module 1 in the uppermost layer in the stacking direction. The current collector plate 3 for the negative electrode is located below the cell module 1 in the lowermost layer.

[0014] Figure 2 is a diagram showing a configuration example of a "single cell" included in the cell module 1 shown in Figure 1. In Figure 2, the configuration around the single cell 4 located in the uppermost layer of the cell module 1 is depicted. As shown in Figure 2, the single cell 4 includes a positive electrode 41, a negative electrode 42, a separator 43, a positive electrode foil 44, and a negative electrode foil 45.

[0015] The positive electrode 41 and the negative electrode 42 have a planar shape. The positive electrode 41 and the negative electrode 42 are made of a metal material such as nickel, for example. The positive electrode 41 contains a positive electrode active material (for example, nickel hydride). The negative electrode 42 contains a negative electrode active material (for example, a hydrogen storage alloy). The separator 43 is formed in a sheet shape. The separator 43 is configured using, for example, a porous membrane formed from a polyolefin-based resin. The positive electrode foil 44 and the negative electrode foil 45 are made of a metal material such as aluminum or copper. The negative electrode foil 45 is in contact with the positive electrode foil 44 of another single cell 4 located directly below the single cell 4.

[0016] Figure 2 also shows a configuration other than the cell module 1 included in the assembled battery B shown in Figure 1. As shown in Figure 2, a spacer 2 is provided above the positive electrode foil 44. A thermistor 5 is provided on the spacer 2. The spacer 2 is provided to protect the thermistor 5 from the load in the stacking direction. The thermistor 5 is a temperature sensor provided for the purpose of measuring the temperature of the cell module 1. The thermistor 5 includes an element portion 51 for measuring temperature and a wiring 52. One end of the wiring 52 is connected to the element portion 51. The other end of the wiring 52 is located outside the single cell 4.

[0017] Also, as shown in Figure 2, an insulating sheet 6 is provided between the positive electrode foil 44 and the spacer 2. The insulating sheet 6 is provided for the purpose of blocking the electrical connection between the element portion 51 and the positive electrode foil 44. The insulating sheet 6 is provided so as to cover at least the element portion 51 and the wiring 52. That is, the formation region of the insulating sheet 6 is a part of the surface region of the positive electrode foil 44.

[0018] Furthermore, as shown in FIG. 2, the sizes of the positive electrode foil 44 and the negative electrode foil 45 in the planar direction are larger than those of the positive electrode 41 and the negative electrode 42. Therefore, a space 7 is formed between the positive electrode foil 44 and the negative electrode foil 45. This space 7 is filled with an electrolytic solution (for example, an alkaline solution such as an aqueous potassium hydroxide solution). Outside the space 7, a seal resin 8 is provided. The seal resin 8 is provided in the stacking direction and joins two adjacent single cells 4.

[0019] FIG. 3 is an exploded schematic view of the assembled battery B shown in FIG. 1. In the example shown in FIG. 3, a total of 10 thermistors 5 are provided on both sides of the topmost current collector plate 3. These thermistors 5 are arranged in parallel along the planar direction of the current collector plate 3. Similar to both sides of the topmost current collector plate 3, thermistors 5 are also provided on both sides of the lowermost current collector plate 3. Furthermore, thermistors 5 are also provided on both sides of each spacer 2. The arrangement example of the thermistors 5 in the lowermost current collector plate 3 and each spacer 2 is the same as that of the topmost current collector plate 3.

[0020] The thermistor 5 provided on the topmost current collector plate 3 measures the temperature of the topmost cell module 1. The thermistor 5 provided on the lowermost current collector plate 3 measures the temperature of the lowermost cell module 1. The thermistor 5 provided on the spacer 2 measures the temperature of the cell module 1 located above or below this spacer 2. Which of the upper temperature and the lower temperature is measured is determined based on the position of the temperature measurement surface 53 (see FIG. 5) of the element portion 51.

[0021] FIG. 4 is a partially enlarged view of the assembled battery B shown in FIG. 3. FIG. 4 depicts two layers of spacers 2 and the cell module 1 provided therebetween. As shown in FIG. 4, slits 21 are formed in the spacers 2. The slits 21 are formed from the ends of the spacers 2 toward the central portions and penetrate the slits 21 in the stacking direction. The thermistor 5 (specifically, a part of the element portion 51 and the wiring 52) provided in the slits 21 is housed at the position of these slits 21.

[0022] Slits having the same shape as the slit 21 are also formed in the topmost and bottommost current collector plates 3. The thermistors 5 provided on these current collector plates 3 are housed at the positions of these slits.

[0023] 2. Arrangement Examples of Thermistors FIG. 5 is a schematic diagram showing a first arrangement example of the thermistor 5. In the example shown in FIG. 5, the slit 21 includes a first slit 21A and a second slit 21B. At the position of the first slit 21A, a first thermistor 5A is housed. The first thermistor 5A is the thermistor 5 that measures the temperature of the first cell module 1A. On the other hand, at the position of the second slit 21B, a second thermistor 5B is housed. The second thermistor 5B is the thermistor 5 for measuring the temperature of the second cell module 1B.

[0024] In the example shown in FIG. 5, the first thermistor 5A or the second thermistor 5B may be housed at the positions of the first slit 21A and the second slit 21B. As described with reference to FIG. 3, the thermistors 5 are provided on both sides of the spacer 2. Therefore, when the first thermistor 5A is arranged on one side of the spacer 2 and the second thermistor 5B is arranged on the other side of the spacer 2, the first thermistor 5A or the second thermistor 5B is housed at the positions of the first slit 21A and the second slit 21B.

[0025] FIG. 6 is a schematic diagram showing a second arrangement example of the thermistor 5. In the example shown in FIG. 6, the first thermistor 5A and the second thermistor 5B are housed in pairs at the position of the slit 21. That is, in the example shown in FIG. 6, the slit 21 is shared by the first thermistor 5A and the second thermistor 5B.

[0026] According to the example shown in FIG. 6, it is possible to reduce the total volume of the slit 21 and the installation area of the insulating sheet 6 compared to the example shown in FIG. 5. On the other hand, according to the example shown in FIG. 5, it is possible to support the load in the stacking direction by the spacer 2 located between the first slit 21A and the second slit 21B and protect the first thermistor 5A and the second thermistor 5B.

[0027] 3. Effects FIG. 7 is a schematic diagram showing a configuration example (reference example) when the thermistors 5 are stacked and arranged in the stacking direction. In the example shown in FIG. 7, the first thermistor 5A and the second thermistor 5B are housed in the positions of the slits 91 formed in the spacer 9. Other points are the same as the example shown in FIG. 6. As can be seen by comparing FIGS. 6 and 7, in the example shown in FIG. 7, the thickness (length in the stacking direction) of the spacer 9 increases by the amount of stacking the first thermistor 5A and the second thermistor 5B.

[0028] In this regard, according to the examples shown in FIGS. 5 and 6, the first thermistor 5A and the second thermistor 5B are arranged along the plane direction of the spacer 2. Therefore, it is possible to make the substantial thickness of the spacer 2 equivalent to the thickness of the first thermistor 5A and the second thermistor 5B. Therefore, when individually measuring the temperatures of the first cell module 1A and the second cell module 1B, it is possible to suppress an increase in the thickness of the spacer 2. This is expected to contribute to reducing the thickness of the assembled battery B.

Explanation of Reference Numerals

[0029] 1 Cell module 1A First cell module 1B Second cell module 2, 9 Spacer 21, 91 Slit 21A First slit 21B Second slit 4 Single cell 5 Thermistor (temperature sensor) 51 Element part 52 Wiring 53 Temperature measurement surface 5A First thermistor 5B Second thermistor B Assembled battery

Claims

【Claim 1】 A first cell module including a stack of a plurality of single cells; A second cell module stacked on the first cell module and including a stack of a plurality of single cells; A spacer provided between the first and second cell modules; A first temperature sensor provided on the spacer for measuring the temperature of the first cell module; A second temperature sensor provided on the spacer for measuring the temperature of the second cell module; comprising the first and second temperature sensors are arranged in parallel along the planar direction of the spacer, the spacer includes a slit formed in the planar direction, the first and second temperature sensors are arranged in pairs in the slit A battery pack characterized by the above.

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