Battery device

Abstract

This technology provides a method for accurately detecting the internal temperature of a battery cell in a secondary battery. [Solution] The battery device comprises a battery cell of a secondary battery. The battery device also comprises a transparent member provided in the case of the battery cell, connecting the inside and outside of the case. Furthermore, the battery device comprises an infrared temperature sensor that contacts the transparent member on the outside of the case.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a secondary battery. A battery temperature sensor for measuring the temperature of the secondary battery is attached to the outer surface of the case of the secondary battery with an adhesive tape or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the technique disclosed in Patent Document 1, a battery temperature sensor for measuring the temperature of a secondary battery is attached to the outer surface of the case of the secondary battery. However, there is a temperature difference between the inside and the outside of the case. Therefore, with the technique disclosed in Patent Document 1, the temperature inside the secondary battery cannot be accurately detected.

[0005] One object of the present disclosure is to provide a technique capable of accurately detecting the temperature inside a battery cell of a secondary battery.

Means for Solving the Problems

[0006] One aspect of the present disclosure relates to a battery device. The battery device includes a battery cell of a secondary battery, a transparent member provided on the case of the battery cell and connecting the inside and the outside of the case, and an infrared temperature sensor that contacts the transparent member on the outside of the case. <9000038>and includes.

Effects of the Invention

[0007] According to this disclosure, a transparent member is provided in the case of the battery cell. An infrared temperature sensor is also provided on the outside of the case so as to be in contact with the transparent member. Such an infrared temperature sensor can detect infrared radiation emitted from an object inside the cell case through the transparent member and measure the temperature of the object with high accuracy. In other words, the combination of the transparent member and infrared temperature makes it possible to detect the internal temperature of the battery cell with high accuracy. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing the schematic configuration of a battery device according to an embodiment. [Figure 2] This is a schematic diagram showing an example of the configuration of a battery cell according to an embodiment. [Figure 3] This is a schematic diagram illustrating the configuration related to the temperature sensor in the comparative example. [Figure 4] This is a schematic diagram illustrating the configuration related to the temperature sensor according to the embodiment. [Figure 5] This is an enlarged view of the periphery of the transparent member according to the embodiment. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described with reference to the attached drawings.

[0010] 1.Schematic configuration Figure 1 is a block diagram showing the schematic configuration of a battery device 1 according to this embodiment. The battery device 1 includes a secondary battery 10. The secondary battery 10 includes one or more battery cells 20. The secondary battery 10 may also include a battery module containing a plurality of battery cells 20. The secondary battery 10 is, for example, a lithium-ion battery. However, the secondary battery 10 is not limited to a lithium-ion battery.

[0011] It is desirable to detect (estimate) the internal temperature of the battery cell 20 in order to ensure proper charging and discharging of the secondary battery 10, and to detect overcharging and discharging of the secondary battery 10. Furthermore, if the secondary battery 10 is a lithium-ion battery, it is desirable to detect (estimate) the temperature of the active material inside the battery cell 20 in order to prevent lithium deposition. For this purpose, the secondary battery 10 includes a temperature sensor 50 for detecting (estimate) the internal temperature of the battery cell 20. Details of the temperature sensor 50 will be described later.

[0012] The battery device 1 further includes a control device 100 configured to control the secondary battery 10. For example, the control device 100 acquires information on the temperature detected by the temperature sensor 50 (hereinafter referred to as "sensor-detected temperature Tsen"). The control device 100 then controls the secondary battery 10 (battery cell 20) based on the sensor-detected temperature Tsen. For example, the control device 100 controls the charging of the secondary battery 10 (battery cell 20) based on the sensor-detected temperature Tsen. The control device 100 may include one or more processors and one or more storage devices. The processors perform various information processing. The storage devices store various information. The functions of the control device 100 may be realized through the cooperation of the processor that executes the control program and the storage devices. The control program may be recorded on a computer-readable recording medium. The control program may be provided via a network.

[0013] The battery device 1 is installed, for example, in a vehicle. The vehicle may be configured to use an electric motor as at least part of its powertrain. Examples of such vehicles include electric vehicles (EVs), hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), and the like. The electric motor is driven by power output from the secondary battery 10 of the battery device 1.

[0014] FIG. 2 is a schematic diagram showing a configuration example of the battery cell 20. The battery cell 20 includes a cell case 21. The cell case 21 is, for example, an aluminum case. The battery cell 20 further includes a plurality of electrodes 22 disposed within the cell case 21. The battery cell 20 further includes a terminal 23 electrically connected to the electrodes 22. The terminal 23 protrudes outside the cell case 21 through the lid 21C of the cell case 21.

[0015] Also, the bottom surface of the cell case 21 of the battery cell 20 is connected to the cooler 40 via the heat conductive member 30. The cooler temperature Tc is the temperature of the cooler 40. The cooler temperature Tc is, for example, 40°C. The temperature inside the cell case 21 does not necessarily coincide with the cooler temperature Tc. For example, the difference between the temperature at the lower part of the electrode 22 and the cooler temperature Tc is about 3°C, the difference between the temperature at the middle part of the electrode 22 and the cooler temperature Tc is about 4°C, and the difference between the temperature at the upper part of the electrode 22 and the cooler temperature Tc is about 5°C.

[0016] 2. Device of Temperature Sensor As described above, the secondary battery 10 includes a temperature sensor 50 for detecting the temperature inside the battery cell 20. The sensor detection temperature Tsen detected by the temperature sensor 50 is used for controlling charging etc. of the secondary battery 10. Hereinafter, the configuration related to the temperature sensor 50 will be described in detail.

[0017] First, a comparative example will be described. FIG. 3 is a schematic diagram for explaining a configuration related to the temperature sensor 50 according to the comparative example. In the comparative example, the temperature sensor 50 is a thermistor 50A. The thermistor 50A is attached to the outer surface of the cell case 21 (aluminum case). For example, the thermistor 50A is attached to the outer surface of the lid 21C of the cell case 21. The thermistor 50A detects the temperature of the outer surface of the cell case 21. That is, the sensor detection temperature Tsen is the temperature of the outer surface of the cell case 21.

[0018] Since heat is transferred through the cell case 21 (aluminum case), the difference between the temperature of the lid 21C of the cell case 21 and the cooler temperature Tc is about 2°C. That is, the difference between the sensor-detected temperature Tsen and the cooler temperature Tc is about 2°C. On the other hand, the difference between the temperature at the upper part of the electrode 22 and the cooler temperature Tc is about 5°C. Therefore, the temperature difference (internal-external temperature difference ΔT) between the sensor-detected temperature Tsen and the internal temperature Tin of the battery cell 20 is at most about 3°C.

[0019] For the control of charging etc. of the secondary battery 10 (battery cell 20), it is necessary to use the internal temperature Tin of the battery cell 20. Considering the above internal-external temperature difference ΔT and the estimation error, the estimated value of the internal temperature Tin of the battery cell 20 is represented by the following formula (1).

[0020] Formula (1): Internal temperature Tin (estimated value) = Sensor-detected temperature Tsen + Internal-external temperature difference ΔT + Estimation error

[0021] Since the estimation error is determined considering the worst conditions that can occur in the market, it is often excessive. Therefore, the estimated value of the internal temperature Tin obtained by formula (1) is likely to deviate from the actual value of the internal temperature Tin. That is, the estimation accuracy of the internal temperature Tin is low. For example, the estimated value of the internal temperature Tin is lower than the actual temperature of the active material in the battery cell 20. The control of the secondary battery 10 based on such a low-precision internal temperature Tin is not necessarily optimal. For example, since it is necessary to set the allowable current during charging conservatively, the time required for rapid charging becomes longer.

[0022] Therefore, this embodiment proposes a technique that can detect the internal temperature Tin of the battery cell 20 of the secondary battery 10 with higher accuracy.

[0023] Figure 4 is a schematic diagram illustrating the configuration related to the temperature sensor 50 according to this embodiment. According to this embodiment, a transparent member 25 is provided in a part of the cell case 21 of the battery cell 20. More specifically, the transparent member 25 is provided so as to connect the inside and outside of the cell case 21. In other words, the transparent member 25 is provided so as to penetrate the cell case 21. In the example shown in Figure 4, the transparent member 25 is provided on the lid 21C of the cell case 21. The transparent member 25 is, for example, transparent glass. As another example, the transparent member 25 may be a transparent resin (e.g., PMMA, PET, PC, PVC). Such a transparent member 25 serves as a “window” provided in a part of the cell case 21.

[0024] According to this embodiment, the temperature sensor 50 is an infrared temperature sensor 50B (radiation temperature sensor). The infrared temperature sensor 50B can detect infrared radiation emitted from an object and measure the temperature of the object with high accuracy based on the infrared radiation energy. Such an infrared temperature sensor 50B is installed on the outside of the cell case 21 so as to be in contact with the transparent member 25.

[0025] Therefore, the infrared temperature sensor 50B can detect infrared radiation emitted from an object (e.g., active material) inside the cell case 21 through the transparent member 25, and measure the temperature of the object with high accuracy. In other words, the combination of the transparent member 25 and the infrared temperature sensor 50B makes it possible to detect the internal temperature Tin of the battery cell 20 with high accuracy. The sensor-detected temperature Tsen detected by the infrared temperature sensor 50B is approximately equal to the internal temperature Tin of the battery cell 20. That is, the internal temperature Tin of the battery cell 20 is expressed by the following equation (2).

[0026] Equation (2): Internal temperature Tin = Sensor-detected temperature Tsen

[0027] The secondary battery 10 is controlled based on the internal temperature Tin given by equation (2). In other words, the secondary battery 10 is controlled by directly using the sensor-detected temperature Tsen detected by the infrared temperature sensor 50B. In this case, there is no need to consider estimation errors. Since a highly accurate internal temperature Tin can be obtained and estimation errors do not need to be considered, optimal control becomes possible. For example, there is no need to set the allowable current conservatively, and the allowable current can be increased, making it possible to shorten the time required for rapid charging.

[0028] In the example shown in Figure 4, the transparent member 25 is provided on the lid 21C of the cell case 21. The infrared temperature sensor 50B is installed on top of the transparent member 25 on the lid 21C. By providing the transparent member 25 and the infrared temperature sensor 50B on the opposite side of the cooler 40, it becomes possible to detect with high accuracy the temperature at the top of the electrode 22 where the difference with the cooler temperature Tc is greatest. In other words, it becomes possible to detect with high accuracy the temperature at a position where the estimation error is large in the comparative example above.

[0029] Figure 5 is an enlarged view of the area around the transparent member 25. As shown in Figure 5, a sealing rubber 27 may be interposed between the transparent member 25 and the cell case 21. The sealing rubber 27 is positioned to cover the ends of the cell case 21 and the transparent member 25. This sealing rubber 27 connects the cell case 21 and the transparent member 25 and prevents the transparent member 25 from falling off. The sealing rubber 27 also protects the ends of the cell case 21 and the transparent member 25.

[0030] An example of how to attach the transparent member 25 and the infrared temperature sensor 50B is as follows. First, an opening is formed in a part of the cell case 21. Meanwhile, an integrated part is prepared with a sealing rubber 27 attached to the end of the transparent member 25. Then, this integrated part is fitted into the opening of the cell case 21. After that, the infrared temperature sensor 50B is attached so as to be in contact with the transparent member 25.

[0031] 3. Effects As described above, according to this embodiment, a transparent member 25 is provided on the cell case 21 of the battery cell 20. In addition, an infrared temperature sensor 50B is installed on the outside of the cell case 21 so as to be in contact with the transparent member 25. Such an infrared temperature sensor 50B can detect infrared radiation emitted from an object inside the cell case 21 through the transparent member 25 and measure the temperature of the object with high accuracy. In other words, the combination of the transparent member 25 and the infrared temperature sensor 50B makes it possible to detect the internal temperature Tin of the battery cell 20 with high accuracy.

[0032] Furthermore, according to this embodiment, the secondary battery 10 is controlled based on the internal temperature Tin. In other words, the secondary battery 10 is controlled by directly using the sensor-detected temperature Tsen detected by the infrared temperature sensor 50B. In this case, there is no need to consider estimation errors. Since a highly accurate internal temperature Tin can be obtained and estimation errors do not need to be considered, optimal control becomes possible. For example, there is no need to set the allowable current conservatively, and the allowable current can be increased, making it possible to shorten the time required for rapid charging. [Explanation of Symbols]

[0033] 1 Battery device 10 Secondary battery 20 battery cells 21 Cell Case 25 Transparent component 27 Seal rubber 50 Temperature Sensors 50B Infrared Temperature Sensor 100 Control device

Claims

1. Battery cells of secondary batteries, A transparent member is provided in the case of the battery cell, connecting the inside and outside of the case, An infrared temperature sensor in contact with the transparent member on the outside of the case and Equipped with battery device.

2. A battery device according to claim 1, The transparent member is provided on the lid of the case. battery device.

3. A battery device according to claim 1, The transparent member is made of transparent glass or transparent resin. battery device.

4. A battery device according to claim 1, A sealing rubber is interposed between the transparent member and the case. battery device.

5. A battery device according to any one of claims 1 to 4, The control device is further configured to control the secondary battery based on the temperature detected by the infrared temperature sensor. battery device.

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