Internal temperature monitoring device for new energy battery box

Abstract

The utility model discloses a new energy battery box internal temperature monitoring device which comprises a battery box, a plurality of lithium ion batteries are arranged in the battery box, NiCr / NiSi film thermocouples are attached to the surfaces of the plurality of lithium ion batteries, a plurality of multifunctional multimeters are arranged on one side of the battery box, and a plurality of temperature sensors are arranged on the other side of the battery box. The plurality of lithium ion batteries are respectively connected with the plurality of multifunctional multimeters through NiCr / NiSi thin film thermocouples, and each NiCr / NiSi thin film thermocouple comprises a polyimide substrate, a SiO2 insulating film, a NiSi thin film, a NiCr thin film and an Al2O3 insulating film. The film thermocouple not only can play an insulation protection role, but also has toughness and can be better attached to the internal structure of the new energy battery box, in addition, polyimide belongs to a thermosetting composite material, can bear the high temperature of 400 DEG C or above and is far higher than the internal temperature of the new energy battery box, and the film thermocouple can be protected at the high temperature.

Description

Technical Field

[0001] The utility model relates to the technical field of thin-film thermocouple temperature sensors, and particularly relates to a temperature monitoring device inside a new energy battery box. Background Technique

[0002] Nowadays, the global manufacturing industry pays more and more attention to the development and utilization of new energy vehicles with low cost and low energy. There is an urgent need to develop new energy battery boxes with better safety performance and longer cruising range. However, a relatively high working temperature will significantly reduce the cycle life of new energy vehicle battery boxes, causing them to quickly overheat, which may lead to spontaneous combustion and related safety problems. On the contrary, low charging or working temperatures will reduce key performance indicators such as battery capacity and charge-discharge efficiency, resulting in a decline in the overall performance of new energy vehicles. In view of this, in recent years, the research on battery thermal management technology has become increasingly popular. However, the existing thermocouple technology still has limitations such as a limited temperature measurement range and low sensitivity. If the internal temperature of the new energy battery box cannot be accurately measured, it may bring serious safety problems to the users of new energy vehicles. Therefore, it is very necessary to develop a temperature sensor with high sensitivity, stability, and operating temperature range for application in the battery thermal management system.

[0003] Due to the thin electrode layers of different materials, thin-film thermocouples have the advantages of fast thermal contact response and high sensitivity. Due to the simple thermoelectric principle of temperature measurement and the rapid development of modern thin-film deposition technology, thin-film thermocouple technology is gradually becoming one of the main temperature measurement methods in the field of temperature measurement of energy battery boxes. All along, the temperature test environment inside the new energy battery box is complex and dangerous, so it is impossible to accurately obtain the internal real-time temperature and mechanism. Therefore, there is an urgent need to prepare a thin-film thermocouple temperature sensor suitable for measuring the temperature inside the new energy battery box to provide a reliable basis for studying the internal real-time temperature performance of the new energy battery box.

[0004] With the development of the new energy vehicle industry, the safety of new energy vehicles has become a hot topic. The battery thermal management system is crucial for keeping the battery temperature within an appropriate range and reducing the overall temperature difference between batteries. Among them, the accuracy of the temperature sensor in measuring temperature significantly affects the performance of the battery thermal management system.

[0005] However, traditional thermocouples have the following disadvantages:

[0006] The existing thermocouple technology has problems such as inaccurate temperature measurement and high cost, which makes it difficult to realize the real-time monitoring of the internal temperature of the new energy battery box. Content of the Utility Model

[0007] The purpose of the present utility model is to provide a temperature monitoring device inside a new energy battery box, so as to solve the problems of inaccurate temperature measurement and high cost existing in the existing thermocouple technology in the above-mentioned background technology, which makes it difficult to realize the real-time monitoring of the temperature inside the new energy battery box.

[0008] To achieve the above object, the present utility model provides the following technical solutions: An internal temperature monitoring device for a new energy battery box, comprising a battery box, wherein a plurality of lithium-ion batteries are arranged inside the battery box, and NiCr / NiSi thin film thermocouples are attached to the surfaces of the plurality of lithium-ion batteries. A plurality of multi-functional multimeters are arranged on one side of the battery box, and the plurality of lithium-ion batteries are respectively connected to the plurality of multi-functional multimeters through NiCr / NiSi thin film thermocouples. The NiCr / NiSi thin film thermocouple includes a polyimide substrate, a SiO2 insulating film, a NiSi thin film, a NiCr thin film, and an Al2O3 insulating film. The top end of the polyimide substrate is fixedly connected to the bottom end of the SiO2 insulating film. One side of the top end of the SiO2 insulating film is fixedly connected to the bottom end of the NiSi thin film, and the other side of the top end of the SiO2 insulating film is fixedly connected to the bottom end of the NiCr thin film. The top ends of the NiSi thin film and the NiCr thin film are respectively fixedly connected to both sides of the bottom end of the Al2O3 insulating film. NiCr and NiSi are selected as the thermocouple materials because the thermocouple materials of the thin film thermocouple sensor not only affect the service life of the thin film thermocouple, but also are related to its thermoelectric performance. NiSi has the advantages of low resistivity and good thermal stability, and NiCr is resistant to high temperature, corrosion, and has good mechanical properties. Therefore, it has broad application prospects in high-temperature fields such as aerospace and is used as high-temperature components. The internal temperature monitoring of the new energy battery box has broad application prospects. These are the traditional application fields of NiCr and NiSi. However, in future temperature sensing, especially in the temperature monitoring of transient and microscopic components, more efforts should be made to develop. Compared with other temperature sensing technologies such as the thermocouple technology at the present stage, the NiCr / NiSi thin film thermocouple sensor has the advantages of a large temperature measurement range, high sensitivity of the thermal junction, and fast response speed, and is more suitable for real-time temperature measurement inside the new energy battery box. Polyimide is selected as the substrate material because it can not only play an insulating and protective role, but also has toughness to better fit the internal structure of the new energy battery box;The first layer selects the SiO2 insulating film. SiO2 has good insulation and stable chemical properties, which can prevent the thin-film thermocouple sensor from oxidation, wear and damage during the temperature measurement process. The top layer selects the Al2O3 insulating film 55 to prevent the loss of thermal electromotive force and ensure the electrical isolation between the thermocouple and the metal substrate. The thin-film thermocouple hot electrodes are connected to the multifunctional multimeter through compensating wires, so as to measure the potential difference, and then measure the real-time temperature inside the new energy battery box. The above-mentioned thin-film thermocouples are pasted on the upper side structure, left side structure and lower side structure of the new energy battery box, and one is pasted on the upper, middle and lower parts of each side, a total of 9. In this way, a thin-film thermocouple sensor that can monitor the temperature inside the new energy battery box is designed. The L-shaped short sides of the second layer NiSi and the third layer NiCr overlap to form a thermal junction, that is, the hot end, and the other end is the cold end. When the temperatures of the hot and cold ends are different, a potential difference will be generated, and the real-time temperature is obtained through the potential difference, that is, the thermoelectric effect, which not only has a fast response speed but also high sensitivity.;

[0009] Preferably, an embedded foam outer layer is sleeved outside the battery box.

[0010] Preferably, several of the multifunctional multimeters each include a multimeter case and a display screen. The top end of one side of the multimeter case is fixedly connected to one side of the display screen. The bottom end of one side of the multimeter case is respectively fixedly installed with a positive electrode connector and a negative electrode connector. An adjustment knob is fixedly installed on the multimeter case on the side of the positive electrode connector. The SiO2 insulating film 52, Al2O3 insulating film 55, NiCr thin film 54, and NiSi thin film 53 are all formed on the polyimide substrate 51 by magnetron sputtering technology, and the purity of the target materials is 99.99%, which fully ensures the uniformity and purity of the thin films and extends their service life. In addition, the thin-film thermocouple hot electrodes are connected to the multifunctional multimeter 3 through compensating wires, so as to measure the potential difference, and then measure the real-time temperature inside the new energy battery box 2. The first compensating wire connecting the thin-film thermocouple and the multimeter uses a NiCr lead, and the second compensating wire uses a NiSi lead.

[0011] Preferably, the ends of several positive electrode connectors away from the multimeter case and the ends of several negative electrode connectors away from the multimeter case are respectively connected to several NiCr / NiSi thin-film thermocouples through wires. The thin-film thermocouples are pasted on the upper side structure, left side structure and lower side structure of the new energy battery box 2, and one is pasted on the upper, middle and lower parts of each side, a total of 9.

[0012] Preferably, several of the lithium-ion batteries are fixedly set to be cylindrical. The polyimide is selected as the base material because it can not only play an insulating and protective role, but also has toughness to better fit the internal structure of the new energy battery box 2. In addition, the polyimide belongs to a thermosetting composite material and can withstand temperatures above 400 °C, which is much higher than the internal temperature of the new energy battery box and can protect the thin-film thermocouple at high temperatures.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0014] 1. The short L-shaped sides of the second layer of NiSi and the third layer of NiCr overlap to form a thermal junction, i.e., the hot end, and the other end is the cold end. When there is a temperature difference between the hot and cold ends, a potential difference will be generated. The temperature is measured through the potential difference, i.e., the thermoelectric effect. The thermoelectric electrodes of the thin-film thermocouple are connected to a multi-functional multimeter through compensating wires, so as to measure the potential difference, and then measure the internal temperature of the new energy battery box. It not only has a fast response speed but also high sensitivity;

[0015] 2. The thin-film thermocouples are attached to the upper side structure, left side structure, and lower side structure of the new energy battery box, and one is attached to each of the upper, middle, and lower parts of each side, for a total of 9. The 9 groups of data corroborate each other, making the test data more reliable;

[0016] 3. Polyimide is selected as the base material because it can not only play an insulating and protective role but also has toughness to better fit the internal structure of the new energy battery box. In addition, polyimide belongs to a thermosetting composite material and can withstand temperatures above 400 °C, which is much higher than the internal temperature of the new energy battery box, and can protect the thin-film thermocouple at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a side view of the present utility model;

[0018] Figure 2 is an exploded view of the NiCr / NiSi thin-film thermocouple of the present utility model;

[0019] Figure 3 is a connection diagram of the multi-functional multimeter and the NiCr / NiSi thin-film thermocouple of the present utility model;

[0020] Figure 4 is a connection diagram of the battery box and the embedded foam outer layer of the present utility model;

[0021] Figure 5 is a connection diagram of the lithium-ion battery and the NiCr / NiSi thin-film thermocouple of the present utility model.

[0022] In the figure: 1. Embedded foam outer layer; 2. Battery box; 3. Multi-functional multimeter; 31. Multimeter case; 32. Display screen; 33. Positive terminal; 34. Negative terminal; 35. Adjustment knob; 4. Lithium-ion battery; 5. NiCr / NiSi thin-film thermocouple; 51. Polyimide substrate; 52. SiO2 insulating film; 53. NiSi thin film; 54. NiCr thin film; 55. Al2O3 insulating film. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model.

[0024] Please refer to Figures 1-5, the present utility model provides an internal temperature monitoring device for a new energy battery box, which includes a battery box 2. Inside the battery box 2, there are several lithium-ion batteries 4. NiCr / NiSi thin film thermocouples 5 are attached to the surfaces of the several lithium-ion batteries 4. On one side of the battery box 2, there are several multi-functional multimeters 3. The several lithium-ion batteries 4 are respectively connected to the several multi-functional multimeters 3 through the NiCr / NiSi thin film thermocouples 5. The NiCr / NiSi thin film thermocouple 5 includes a polyimide substrate 51, a SiO2 insulating film 52, a NiSi thin film 53, a NiCr thin film 54, and an Al2O3 insulating film 55. The top end of the polyimide substrate 51 is fixedly connected to the bottom end of the SiO2 insulating film 52. One side of the top end of the SiO2 insulating film 52 is fixedly connected to the bottom end of the NiSi thin film 53. The other side of the top end of the SiO2 insulating film 52 is fixedly connected to the bottom end of the NiCr thin film 54. The top ends of the NiSi thin film 53 and the NiCr thin film 54 are respectively fixedly connected to both sides of the bottom end of the Al2O3 insulating film 55. NiCr and NiSi are selected as the thermoelectrode materials because the thermoelectrode materials of the thin film thermocouple sensor not only affect the service life of the thin film thermocouple, but also are related to its thermoelectric performance. NiSi has the advantages of low resistivity and good thermal stability. NiCr is resistant to high temperature, corrosion, and also has good mechanical properties. Therefore, it has broad application prospects in high-temperature fields such as aerospace and is used as high-temperature components. There are broad application prospects for internal temperature monitoring of new energy battery boxes; these are the traditional application fields of NiCr and NiSi. However, in future temperature sensing, especially in the temperature monitoring of transient and micro-component parts, more efforts should be made to develop. Compared with other temperature sensing technologies such as the current thermocouple technology, the NiCr / NiSi thin film thermocouple sensor has the advantages of a larger temperature measurement range, high sensitivity of the thermal junction, and fast response speed, and is more suitable for real-time temperature measurement inside the new energy battery box. Polyimide is selected as the substrate material because it can not only play an insulating and protective role, but also has toughness to better fit the internal structure of the new energy battery box;The first layer selects the SiO2 insulating film 52. SiO2 has good insulation and stable chemical properties, which can prevent the thin-film thermocouple sensor from oxidation, abrasion and damage during the temperature measurement process. The outermost layer selects the Al2O3 insulating film 55 to prevent the loss of thermal electromotive force and ensure the electrical isolation between the thermocouple and the metal substrate. The thin-film thermocouple hot electrodes are connected to the multifunctional multimeter 3 through compensating wires, so as to measure the potential difference, and then measure the real-time temperature inside the new energy battery box. The above-mentioned thin-film thermocouples are pasted on the upper side structure, left side structure and lower side structure of the new energy battery box, and one is pasted on the upper, middle and lower parts of each side, a total of 9. In this way, a thin-film thermocouple sensor that can monitor the temperature inside the new energy battery box is designed. The short side of the L-shaped of the second layer NiSi and the third layer NiCr overlaps to form a thermal junction, that is, the hot end, and the other end is the cold end. When the temperatures of the hot and cold ends are different, a potential difference will be generated. The real-time temperature is obtained through the potential difference, that is, the thermoelectric effect, which not only has a fast response speed but also high sensitivity.;

[0025] The outer side of the battery box 2 is sleeved with an embedded foam outer layer 1.

[0026] Several multifunctional multimeters 3 all include a multimeter case 31 and a display screen 32. The top end of one side of the multimeter case 31 is fixedly connected to one side of the display screen 32. The bottom end of one side of the multimeter case 31 is respectively fixedly installed with a positive terminal 33 and a negative terminal 34. An adjustment knob 35 located on one side of the positive terminal 33 is fixedly installed on the multimeter case 31. The SiO2 insulating film 52, Al2O3 insulating film 55, NiCr thin film 54, and NiSi thin film 53 are all generated on the polyimide substrate 51 by magnetron sputtering technology. The purity of the target materials is 99.99%, which fully ensures the uniformity and purity of the thin films and extends their service life. In addition, the thin-film thermocouple hot electrodes are connected to the multifunctional multimeter 3 through compensating wires, so as to measure the potential difference, and then measure the real-time temperature inside the new energy battery box 2. The first compensating wire connecting the thin-film thermocouple and the multimeter uses a NiCr lead, and the second compensating wire uses a NiSi lead.

[0027] One end of several positive terminals 33 far from the multimeter case 31 and one end of several negative terminals 34 far from the multimeter case 31 are respectively connected to several NiCr / NiSi thin-film thermocouples 5 through wires. The thin-film thermocouples are pasted on the upper side structure, left side structure and lower side structure of the new energy battery box 2, and one is pasted on the upper, middle and lower parts of each side, a total of 9.

[0028] A number of lithium-ion batteries 4 are fixedly arranged in a cylindrical shape. Polyimide is selected as the base material because it can not only play an insulating and protective role, but also has toughness to better fit the internal structure of the new energy battery box 2. In addition, polyimide belongs to a thermosetting composite material and can withstand temperatures above 400 °C, which is much higher than the internal temperature of the new energy battery box, and can protect the thin-film thermocouple at high temperatures.

[0029] When the embodiment of the present application is in use: the SiO2 insulating film 52, the Al2O3 insulating film 55, the NiCr thin film 54, and the NiSi thin film 53 are all formed on the polyimide substrate 51 by magnetron sputtering technology. The purity of the target materials is 99.99%, which fully ensures the uniformity and purity of the thin films and extends their service life. The L-shaped short sides of the second-layer NiSi thin film 53 and the third-layer NiCr thin film 54 overlap to form a thermal junction, that is, the hot end, and the other end is the cold end. When the temperatures of the hot and cold ends are different, a potential difference will be generated, and the real-time temperature is obtained through the potential difference, that is, the thermoelectric effect. It not only has a fast response speed but also high sensitivity. The NiCr / NiSi thin-film thermocouple 5 is closely attached to the 18650-type cylindrical lithium-ion battery 4. The thermal electrodes of the NiCr / NiSi thin-film thermocouple 5 are connected to the multi-functional digital meter 3 through compensating wires, so as to measure the potential difference, and then measure the real-time temperature inside the new energy battery box 2. The NiCr / NiSi thin-film thermocouple 5 is attached to the upper, middle, and lower three batteries on the left-side structure of the new energy battery box 2. Each NiCr / NiSi thin-film thermocouple 5 is connected to a multi-functional digital meter 3. The placement methods of the NiCr / NiSi thin-film thermocouples 5 on the upper-side structure and the lower-side structure are the same as those on the left-side structure, and the connection methods of the multi-functional digital meters 3 are also the same. Therefore, a total of three groups of NiCr / NiSi thin-film thermocouples 5 (9 in total) and three groups of multi-functional digital meters 3 (9 in total) are placed inside the entire new energy battery box 2. The 9 groups of data corroborate each other, making the test data more reliable.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An internal temperature monitoring device for a new energy battery box, comprising a battery box (2), characterized in that: Inside the battery box (2), there are several lithium-ion batteries (4). NiCr / NiSi thin-film thermocouples (5) are attached to the surfaces of the several lithium-ion batteries (4). On one side of the battery box (2), there are several multi-functional multimeters (3). The several lithium-ion batteries (4) are respectively connected to the several multi-functional multimeters (3) through the NiCr / NiSi thin-film thermocouples (5). The NiCr / NiSi thin-film thermocouple (5) includes a polyimide substrate (51), a SiO2 insulating film (52), a NiSi thin film (53), a NiCr thin film (54), and an Al2O3 insulating film (55). The top end of the polyimide substrate (51) is fixedly connected to the bottom end of the SiO2 insulating film (52). One side of the top end of the SiO2 insulating film (52) is fixedly connected to the bottom end of the NiSi thin film (53). The other side of the top end of the SiO2 insulating film (52) is fixedly connected to the bottom end of the NiCr thin film (54). The top ends of the NiSi thin film (53) and the NiCr thin film (54) are respectively fixedly connected to both sides of the bottom end of the Al2O3 insulating film (55).

2. The internal temperature monitoring device for a new energy battery box according to claim 1, characterized in that: An embedded foam outer layer (1) is sleeved outside the battery box (2).

3. The internal temperature monitoring device for a new energy battery box according to claim 1, wherein: The several multi-functional multimeters (3) each include a multimeter case (31) and a display screen (32). The top end of one side of the multimeter case (31) is fixedly connected to one side of the display screen (32).

4. The internal temperature monitoring device for a new energy battery box according to claim 3, characterized in that: At the bottom end of one side of the multimeter case (31), a positive electrode connector (33) and a negative electrode connector (34) are respectively fixedly installed. An adjustment knob (35) is fixedly installed on the multimeter case (31) on one side of the positive electrode connector (33).

5. The internal temperature monitoring device for a new energy battery box according to claim 4, characterized in that: The ends of the several positive electrode connectors (33) away from the multimeter case (31) and the ends of the several negative electrode connectors (34) away from the multimeter case (31) are respectively connected to the several NiCr / NiSi thin-film thermocouples (5) through wires.

6. The internal temperature monitoring device for a new energy battery box according to claim 1, characterized in that: The several lithium-ion batteries (4) are all fixedly arranged in a cylindrical shape.

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