Built-in multi-element sensing device for detecting safety of cylindrical battery

Abstract

The utility model provides a built-in multi-element sensing device for detecting the safety of a cylindrical battery, and relates to the field of battery production and safety detection. According to the multi-element sensing device, the two key parameters of pressure and temperature in the cylindrical battery are monitored at the same time through the built-in pressure sensing unit and the built-in temperature sensing unit, and the problems of false alarm and missing alarm possibly caused by single parameter monitoring are solved. The pressure sensing unit adopts a flexible cylindrical block design, can adapt to the internal structure of a cylindrical battery, and effectively collects pressure information in a 360-degree direction range. The spacers are fixed at the two ends of the pressure sensing unit, so that axial deformation caused by temperature change is prevented, and the accuracy of pressure measurement is improved. The temperature sensing unit adopts a rigid cylindrical tube body design and is arranged at an interval with the pressure sensing unit, so that temperature information can be independently acquired, and mutual interference is avoided. The flexible packaging layer not only plays a role in isolating the electrolyte, but also can be in close contact with the pressure sensing unit and the temperature sensing unit, so that the response time of the sensing units is shortened, and the real-time performance and accuracy of monitoring are improved.

Description

Technical Field

[0001] The present utility model application relates to the field of battery production and safety detection. Specifically, an internal multi-sensor device for detecting the safety of cylindrical batteries is provided. Background Art

[0002] Compared with soft-pack and square batteries, cylindrical batteries have the advantages of mature production technology, high product yield consistency, and low assembly cost. In recent years, large cylindrical batteries have developed rapidly and have been applied in fields such as electric vehicles. Currently, more than 50 enterprises globally have laid out production capacity plans for large cylindrical batteries, and more than 15 enterprises have production capacity plans reaching the GWh level. To achieve the large-scale application of these large cylindrical batteries in fields such as electric vehicles, the primary consideration is safety issues.

[0003] Currently, the sensor devices used to monitor and evaluate the safety of cylindrical batteries are mostly external sensor devices, which mainly monitor surface-level parameters such as the output current and voltage of cylindrical batteries and the temperature of the surface shell. However, with the improvement of their heat dissipation capacity and the optimization of key materials and structures, the above parameters remain unchanged when safety issues occur inside them. Therefore, the existing external sensor devices are no longer suitable for monitoring and evaluating the safety of cylindrical batteries. Internal sensor devices can directly and quickly monitor parameters such as the internal pressure and temperature of cylindrical batteries, and can better reflect the internal situation of cylindrical batteries compared with external sensor devices. Therefore, they are more suitable for monitoring and evaluating the safety of cylindrical batteries.

[0004] In recent years, sensor devices for internally monitoring the safety of batteries have been reported. However, on the one hand, they can only monitor a single parameter, such as temperature, pressure, etc., which is likely to cause false alarms and missed alarms of battery safety problems. On the other hand, the main batteries they are implanted in are soft-pack batteries, and the designed sensor devices are not suitable for being implanted in cylindrical batteries. Some researchers have also designed pressure-temperature sensor devices based on optical fiber structures that can be implanted inside cylindrical batteries, but their processing process is difficult and the monitoring conditions are demanding, which limits their practical applications. In addition, some researchers have designed pressure-temperature sensor devices based on elastomer materials and metal films, and their processing process is relatively simple. However, the internal pressure direction range in cylindrical batteries is mainly in the 360° range of the circular radial direction, and the elastomer material among them can only sense and monitor the pressure in the circular radial direction within about 10° - 20° range. Moreover, there is a relatively thick adiabatic encapsulation layer between the metal film and the electrolyte, which prolongs the time for heat conduction to the sensor device, and thus is likely to cause delays in the pressure and temperature monitoring and perception processes and a decrease in the accuracy of the perception results.

[0005] In view of the above problems, the existing technical means urgently need to be improved. Summary of the Utility Model

[0006] The purpose of this application is to provide a built-in multi-sensor device for detecting the safety of cylindrical batteries. By designing the pressure sensing unit as a flexible cylindrical block, it can adapt to the internal structure of the cylindrical battery and effectively collect pressure information within a 360° range. The spacer is fixed at both ends of the pressure sensing unit to prevent axial deformation caused by temperature changes and improve the accuracy of pressure measurement. By designing the temperature sensing unit as a rigid cylindrical tube that also adapts to the inside of the cylindrical battery and arranging it at intervals with the pressure sensing unit, temperature information can be collected independently to avoid mutual interference. The flexible encapsulation layer is used to isolate the electrolyte and is in close contact with the pressure sensing unit and the temperature sensing unit, which can shorten the response time of the sensing unit and improve the real-time performance and accuracy of monitoring.

[0007] In a first aspect, this application provides a built-in multi-sensor device for detecting the safety of cylindrical batteries, which at least includes a pressure sensing unit, a temperature sensing unit, a spacer, and a flexible encapsulation layer built into the cylindrical battery.

[0008] The pressure sensing unit is in the form of a flexible cylindrical block and is used to collect the pressure inside the cylindrical battery. The spacer is fixed at both ends of the pressure sensing unit to prevent the pressure sensing unit from undergoing axial deformation due to the influence of temperature.

[0009] The temperature sensing unit is in the form of a rigid cylindrical tube and is arranged at intervals on one side of the pressure sensing unit, and is used to collect the temperature inside the cylindrical battery. The pressure sensing unit, the temperature sensing unit, and the spacer are encapsulated in the flexible encapsulation layer. The flexible encapsulation layer is used to isolate the electrolyte and is in close contact with the pressure sensing unit and the temperature sensing unit, which can shorten the response time of the pressure sensing unit and the temperature sensing unit.

[0010] This application integrates multiple sensing units into a sensor device suitable for the internal structure of cylindrical batteries, and through special structural design, realizes comprehensive, accurate, and rapid monitoring of the internal pressure and temperature of cylindrical batteries. This solution not only improves the comprehensiveness and accuracy of monitoring, but also has good practicability and reliability, providing a more effective technical means for the safety assessment of cylindrical batteries.

[0011] Furthermore, sealing plugs are provided at both ends of the cylindrical battery, and the sealing plugs are used to prevent electrolyte leakage and at the same time prevent it from seeping into the pressure sensing unit and the temperature sensing unit.

[0012] An internal multi-sensor device for detecting the safety of cylindrical batteries proposed in this application can effectively enclose the internal space of the battery by setting sealing plugs at both ends of the cylindrical battery, preventing the leakage of the electrolyte outwards and at the same time preventing it from seeping into the pressure sensing unit and the temperature sensing unit. This design can improve the overall safety of the battery with the internal multi-sensor device. The presence of the sealing plugs makes the battery with the internal multi-sensor device more reliable during use, reducing various problems that may be caused by the leakage and infiltration of the electrolyte, such as short circuits and corrosion.

[0013] Furthermore, the internal multi-sensor device further includes wires. There are multiple wires, and the multiple wires are arranged at intervals. One end is connected to the temperature sensing unit or the pressure sensing unit, and the other end extends outwards through the sealing plug and is connected to a signal collector. The wires are used to transmit the battery temperature information collected by the temperature sensing unit and the battery pressure information collected by the pressure sensing unit.

[0014] An internal multi-sensor device for detecting the safety of cylindrical batteries proposed in this application transmits the temperature information collected by the temperature sensing unit and the pressure information collected by the pressure sensing unit by adding wires in the internal multi-sensor device, realizing the transmission of the internal pressure and temperature signals of the cylindrical battery to the outside; the wires extend outwards through the sealing plug, which not only ensures the signal transmission but also does not affect the sealing performance of the battery; the multiple wires are arranged at intervals, which can effectively avoid interference between signals and improve the accuracy of transmission; this technical solution realizes the real-time monitoring and transmission of the internal temperature and pressure information of the cylindrical battery, providing reliable data support for evaluating the battery safety.

[0015] Furthermore, with the extending direction of the wires as the upper side, the pressure sensing unit is arranged below the temperature sensing unit.

[0016] An internal multi-sensor device for detecting the safety of cylindrical batteries proposed in this application arranges the pressure sensing unit below the temperature sensing unit and the temperature sensing unit above. Its wires can directly extend upwards and be connected to the signal collector. The wires of the pressure sensing unit can be transmitted upwards through the hollow structure of the temperature sensing unit, avoiding interference between the wires. This design reduces possible signal interference, thereby improving the accuracy and reliability of data collection.

[0017] Furthermore, the temperature sensing unit is in a cylindrical tubular shape and has a hollow through-hole inside.

[0018] Furthermore, the wires connected to the pressure sensing unit extend outwards through the hollow through-hole of the temperature sensing unit, avoiding interference with the battery pressure information when transmitting the battery temperature information.

[0019] Further, the wire connected to the temperature sensing unit is spaced on the inner wall of the hollow through hole and extends outward.

[0020] Further, insulating coatings are applied on multiple said wires, and the insulating layer is fixedly connected to the sealing plug.

[0021] Further, the spacer is a rigid cylindrical sheet.

[0022] Further, the temperature sensing unit is a rigid cylindrical tube body.

[0023] Beneficial effects: An internal multi-sensor device for detecting the safety of cylindrical batteries proposed in this application. This internal multi-sensor device can simultaneously monitor two key parameters, namely the pressure and temperature inside the cylindrical battery, through the built-in pressure sensing unit and temperature sensing unit, solving the problem of false alarms and missed alarms that may be caused by single-parameter monitoring. The pressure sensing unit adopts a flexible cylindrical block design, which can adapt to the internal structure of the cylindrical battery and effectively collect pressure information within a 360° range. The spacers are fixed at both ends of the pressure sensing unit to prevent axial deformation caused by temperature changes and improve the accuracy of pressure measurement. The temperature sensing unit adopts a rigid cylindrical tube body design that also adapts to the internal structure of the cylindrical battery. It is spaced from the pressure sensing unit and can independently collect temperature information to avoid mutual interference. The flexible encapsulation layer not only plays a role in isolating the electrolyte but also can be in close contact with the pressure sensing unit and the temperature sensing unit, shortening the response time of the sensing unit and improving the real-time performance and accuracy of monitoring. This solution integrates multiple sensing units into a sensor device suitable for the internal structure of the cylindrical battery and, through special structural design, realizes comprehensive, accurate, and rapid monitoring of the pressure and temperature inside the cylindrical battery. It not only improves the comprehensiveness and accuracy of monitoring but also has good practicability and reliability, providing a more effective technical means for the safety assessment of cylindrical batteries. Description of the Drawings

[0024] Figure 1 It is a structural diagram of an internal multi-sensor device for detecting the safety of cylindrical batteries proposed in this application.

[0025] Figure 2 It is a structural diagram of the cylindrical battery proposed in this application.

[0026] Figure 3 It is a relative resistance change data diagram of the pressure sensing unit proposed in this application and the pressure sensing unit in the prior art under the condition of overheating of the cylindrical battery.

[0027] Figure 4 It is a relative resistance change data diagram of the temperature sensing unit proposed in this application and the temperature sensing unit in the prior art under the condition of overheating of the cylindrical battery.

[0028] Figure 5 Figure showing the relative resistance change data of the pressure sensing unit proposed in this application and the pressure sensing unit in the prior art under the condition of needle puncture of a cylindrical battery.

[0029] Figure 6 Figure showing the relative resistance change data of the temperature sensing unit proposed in this application and the temperature sensing unit in the prior art under the condition of needle puncture of a cylindrical battery.

[0030] In the figure: 1. Wire; 2. Insulating coating; 3. Flexible encapsulation layer; 4. Spacer; 5. Sealing plug; 6. Pressure sensing unit; 7. Temperature sensing unit. Detailed implementation manner

[0031] Next, the technical solutions in this application will be clearly and completely described in conjunction with the accompanying drawings in this application. Obviously, the described embodiments are only part of the embodiments of this application, rather than all embodiments. The components of this application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application that is required to be protected, but only represents the selected embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of this application.

[0032] It should be noted that: Similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0033] Currently, in order to solve the problem that the elastomer material in the prior art can only sense the pressure within a range of about 10° - 20° in the circumferential direction. Moreover, there is a relatively thick adiabatic encapsulation layer between the metal thin film and the electrolyte, which prolongs the time for heat conduction to the sensor device, easily causing hysteresis in the pressure and temperature monitoring and sensing processes and reducing the accuracy of the sensing results. This application proposes a built-in multi-sensor device for detecting the safety of cylindrical batteries, and the specific solution is as follows:

[0034] Please refer to Figures 1 to 6 , a built-in multi-sensor device for detecting the safety of cylindrical batteries, at least including a pressure sensing unit 6, a temperature sensing unit 7, a spacer 4, and a flexible encapsulation layer 3 built into the cylindrical battery,

[0035] The pressure sensing unit 6 is in the shape of a flexible cylindrical block and is used to collect the pressure inside the cylindrical battery. The spacer 4 is fixed at both ends of the pressure sensing unit 6 to prevent the pressure sensing unit 6 from undergoing axial deformation due to the influence of temperature;

[0036] The temperature sensing unit 7 is in the form of a rigid cylindrical tube and is arranged at one side of the pressure sensing unit 6 at intervals for collecting the temperature inside the cylindrical battery; the pressure sensing unit 6, the temperature sensing unit 7 and the separator 4 are encapsulated in the flexible encapsulation layer 3; the flexible encapsulation layer 3 is used to isolate the electrolyte, is in close contact with the pressure sensing unit 6 and the temperature sensing unit 7, and shortens the response time of the pressure sensing unit 6 and the temperature sensing unit 7.

[0037] Among them, with reference to Figure 1 , Figure 2 , the cylindrical battery includes but is not limited to 18650, 14500, 26650, 10440, 16340, 21700 and 4680 series batteries.

[0038] Among them, the built-in multi-sensor device proposed in this application at least includes a pressure sensing unit 6, a temperature sensing unit 7, a separator 4 and a flexible encapsulation layer 3 built in the cylindrical battery. This design allows simultaneous monitoring of two key parameters, pressure and temperature, and overcomes the problems of false alarms and missed alarms that may be caused by single-parameter monitoring.

[0039] Considering the internal structural characteristics of the cylindrical battery, the pressure sensing unit 6 adopts a flexible cylindrical block design, which can collect pressure information within a 360° range, solving the problem that the previous pressure sensing unit based on elastomeric materials can only monitor the pressure within a limited angular range. Among them, the pressure sensing unit 6 is a flexible cylindrical block, which is composed of a positive temperature coefficient material and a flexible elastomer. The positive temperature coefficient materials include but are not limited to metal materials (such as gold, nickel, platinum, constantan alloy and karma alloy) and ferroelectric ceramic materials (such as BaTiO3, PbTiO3 and SrTiO3), and preferably, nickel is selected. The flexible elastomers include but are not limited to polydimethylsiloxane, polyurethane, SEBS, Ecoflex and Dragon skin, and preferably, polyurethane is selected.

[0040] In order to improve the accuracy of pressure measurement, the separator 4 is fixed at both ends of the pressure sensing unit 6. This design avoids the axial deformation of the pressure sensing unit 6 caused by temperature influence, ensuring that the pressure measurement result will not be interfered by temperature changes. Among them, the separator 4 is a rigid cylindrical sheet, and the materials it is composed of include but are not limited to polyethylene terephthalate, polyethylene, polypropylene, polymethyl methacrylate and polyether ether ketone, and preferably, polyether ether ketone is selected.

[0041] The temperature sensing unit 7 is arranged at one side of the pressure sensing unit 6 at intervals. This structure allows the temperature sensing unit 7 to independently collect temperature information, avoiding mutual interference with pressure measurement. The temperature sensing unit 7 is a rigid cylindrical tube body and is composed of a positive temperature coefficient material. The positive temperature coefficient materials include, but are not limited to, metal materials (such as gold, nickel, platinum, constantan alloy, and Karma alloy, etc.) and ferroelectric ceramic materials (such as BaTiO3, PbTiO3, and SrTiO3, etc.). Preferably, it is a constantan alloy.

[0042] To solve the problem of the response lag of the previous built-in sensors, the present application uses a flexible encapsulation layer 3 to encapsulate the pressure sensing unit 6, the temperature sensing unit 7, and the spacer 4 together. The flexible encapsulation layer 3 not only plays a role in isolating the electrolyte, but also can be in close contact with the pressure sensing unit 6 and the temperature sensing unit 7, significantly shortening the response time of the sensing unit. Among them, the flexible encapsulation layer 3 is required to be resistant to electrolyte corrosion, and the thickness can be in the range of 0.01 mm - 0.1 mm. The constituent materials include, but are not limited to, polyimide, polyethylene, polypropylene, polytetrafluoroethylene, and polyvinylidene fluoride. Preferably, it is polyimide.

[0043] Furthermore, sealing plugs 5 are arranged at both ends of the cylindrical battery. The sealing plugs 5 are used to prevent electrolyte leakage and at the same time prevent it from penetrating into the pressure sensing unit and the temperature sensing unit.

[0044] Among them, by arranging the sealing plugs 5 at both ends of the cylindrical battery, the internal space of the battery can be effectively sealed. The constituent materials of the sealing plugs 5 include, but are not limited to, 304 stainless steel, 316 stainless steel, polypropylene, polytetrafluoroethylene, polyethylene terephthalate, and polyvinylidene fluoride. Preferably, it is 304 stainless steel. The structure of the sealing plugs 5 can be a simple cylindrical plug or a complex design with a multiple sealing structure. For example, a structure with multiple sealing rings can be adopted, and each sealing ring provides additional sealing protection at different positions. The sealing plugs 5 can be fixed at both ends of the sensor device by pressing, screwing, or buckling, etc.

[0045] Among them, the design of the sealing plugs 5 is closely related to other parts of the built-in multi-sensor device. For example, the sealing plugs 5 need to provide a channel for the wire 1, and at the same time ensure that there is no electrolyte leakage at the place where the wire 1 passes through. This can be achieved by designing a special wire channel on the sealing plugs 5, and the wire channel is hermetically and fixedly connected to the wire 1.

[0046] Furthermore, the built-in multi-sensor device further includes a plurality of wires 1. The plurality of wires 1 are arranged at intervals, with one end connected to the temperature sensing unit 7 or the pressure sensing unit 6, and the other end extending outward through the sealing plug 5 to be connected to the signal collector. The wires 1 are used to transmit the battery temperature information collected by the temperature sensing unit 7 and the battery pressure information collected by the pressure sensing unit 6.

[0047] In some specific embodiments, there are various implementation manners for the arrangement of the wires 1. First of all, the number of the wires 1 can be set to 4 according to needs, and the pressure sensing unit 6 and the temperature sensing unit 7 are respectively connected to two wires to meet the transmission requirements of temperature and pressure information. The wires 1 can be made of copper wires, silver wires or other conductive materials, and the diameter of the wires 1 can be in the range of 0.1 - 0.5 mm. The connection between the wires 1 and the temperature sensing unit 7 and the pressure sensing unit 6 can adopt welding, crimping or plugging and other methods to ensure a stable electrical connection.

[0048] The interval distance between the wires 1 can be set between 0.2 - 2 mm. Such an interval can effectively avoid interference between signals. The interval arrangement can be achieved by wrapping an insulating layer outside the wires 1. The insulating coating 2 is required to be an insulator material and can be firmly combined with the sealing plug 5. The materials of the insulating layer include but are not limited to corundum materials, silicone rubber materials and photocurable glue materials. Preferably, it is preferably a photocurable glue material.

[0049] Furthermore, with the extension direction of the wires 1 as the upper side, the pressure sensing unit 6 is arranged below the temperature sensing unit 7.

[0050] Among them, when the pressure sensing unit 6 is arranged below the temperature sensing unit 7 and the temperature sensing unit 7 is above, its wires 1 can directly extend upward to be connected to the signal collector. And the wires 1 of the pressure sensing unit 6 can be transmitted upward through the hollow structure of the temperature sensing unit 7, avoiding interference between the wires 1. This design not only improves the signal transmission efficiency but also reduces possible signal interference, thereby improving the accuracy and reliability of data acquisition.

[0051] Furthermore, the temperature sensing unit 7 is in a cylindrical tubular shape and has a hollow through hole inside.

[0052] Among them, the cylindrical tubular design matches the internal structure of the cylindrical battery, can better fit the inner wall of the flexible encapsulation layer, improve the accuracy and sensitivity of temperature acquisition, and shorten the response time of temperature acquisition. At the same time, the internal hollow through hole provides a channel for other components such as the wires 1. When the pressure sensing unit 6 is arranged below the temperature sensing unit 7, the wires 1 connected to the pressure sensing unit 6 can extend outward through this hollow through hole, avoiding interference with the wires 1 for transmitting the battery temperature information.

[0053] Further, the wire 1 connected to the pressure sensing unit 6 extends outward through the hollow through-hole of the temperature sensing unit 7, avoiding interference with the battery pressure information when transmitting the battery temperature information.

[0054] Among them, by setting the temperature sensing unit 7 as a cylindrical tubular body with a hollow through-hole, the interference problem that may occur in the transmission of battery temperature information and pressure information is solved. Specifically, the wire 1 of the pressure sensing unit 6 extends outward through the hollow through-hole of the temperature sensing unit 7, separating the transmission paths of the two signals and effectively avoiding signal interference. The wire 1 of the temperature sensing unit 7 is arranged at intervals on the inner wall of the hollow through-hole and extends outward, further ensuring the independent transmission of the two signals. The insulating coating 2 is coated on multiple wires 1 and fixedly connected to the sealing plug 5 to ensure the stability and sealing of the whole structure.

[0055] Further, the wire 1 connected to the temperature sensing unit 7 is arranged at intervals on the inner wall of the hollow through-hole and extends outward.

[0056] Among them, by arranging the wire 1 connected to the temperature sensing unit 7 at intervals on the inner wall of the hollow through-hole of the temperature sensing unit 7 and extending it outward, the effective transmission of temperature information is realized. This arrangement has the following advantages: First, arranging the wire 1 on the inner wall of the hollow through-hole can make full use of the space and avoid interference with the wire 1 of the pressure sensing unit 6. Second, arranging multiple wires 1 at intervals can increase the stability and reliability of signal transmission. Finally, the design of the wire 1 extending outward is convenient for connecting with an external signal collector, facilitating subsequent data processing. Combining this wire 1 arrangement method with the overall design of the built-in multi-sensor device can effectively solve the problems of accurate acquisition and transmission of the internal temperature and pressure information of the cylindrical battery, avoid signal interference, improve the accuracy and reliability of data acquisition, and thus better monitor the safety of the cylindrical battery.

[0057] In the prior art, in order to prevent the wires 1 connecting the temperature sensing unit 7 and the pressure sensing unit 6 from contacting each other, the pressure sensing unit 6 is usually set in a block shape, while the temperature sensing unit 7 is set in a thin film shape. This method will result in a long response time of the temperature sensing unit 7 to temperature changes, and a small relative resistance change of the pressure sensing unit 6 and the temperature sensing unit 7 under the same test time, which is not conducive to the acquisition of battery temperature signals. Specifically refer to Figure 3 、 Figure 4 . Under overheating conditions, the signal change directions of the pressure sensing unit and the temperature sensing unit are opposite, but for the temperature sensing unit, the response time of the temperature sensing unit to the change of battery temperature information in this application is shorter. Specifically refer to Figure 5 、 Figure 6, under acupuncture stimulation, the response time of the pressure sensing unit and the temperature sensing unit proposed in this application is shorter than that of the pressure sensing unit and the temperature sensing unit in the prior art, and under the same test time, the relative resistance change of this application is greater.

[0058] Furthermore, an insulating coating 2 is coated on multiple wires 1, and the insulating layer is fixedly connected to the sealing plug 5.

[0059] Among them, the insulating coating 2 coated on multiple wires 1 can effectively prevent electromagnetic interference between the wires 1 and ensure the accuracy of signal transmission. At the same time, the fixed connection between the insulating coating 2 and the sealing plug 5 can enhance the stability of the wires 1 and prevent the wires 1 from shifting or falling off during use. This design solves the possible interference problem between multiple wires 1 and improves the quality and reliability of signal transmission. The insulating coating 2 not only plays an insulating role, but also enhances the stability of the entire structure through its fixed connection with the sealing plug 5. The fixed connection between the insulating coating 2 and the sealing plug 5 can be achieved in various ways. A common method is to design special grooves or snap structures on the sealing plug 5, and the insulating coating 2 can be embedded or snapped into these structures to achieve a firm connection. The preferred method is to use a high-strength adhesive to bond the insulating coating 2 and the sealing plug 5 together. This method requires selecting an adhesive compatible with the materials of the insulating coating 2 and the sealing plug 5 to ensure a long-term stable connection effect.

[0060] Furthermore, the spacer 4 is a rigid cylindrical sheet.

[0061] Among them, as a rigid cylindrical sheet, the spacer 4 is fixed at both ends of the pressure sensing unit 6, which can effectively prevent the pressure sensing unit 6 from undergoing axial deformation due to temperature influence. The rigid cylindrical sheet has high hardness and stability and can maintain its shape unchanged when the temperature changes, thereby restricting the axial deformation of the pressure sensing unit 6. By using a rigid cylindrical sheet as the spacer 4, the problem of axial deformation of the pressure sensing unit 6 caused by temperature influence can be effectively solved. This design can improve the measurement accuracy of the pressure sensing unit 6, enabling it to more accurately collect the pressure inside the cylindrical battery without being interfered by temperature changes. At the same time, the shape of the rigid cylindrical sheet matches the internal structure of the cylindrical battery, which is beneficial to the stability and compactness of the overall structure. This design not only improves the accuracy of pressure measurement but also enhances the overall reliability and durability of the built-in multi-sensor device.

[0062] Furthermore, the temperature sensing unit 7 is a rigid cylindrical tube.

[0063] Among them, the temperature sensing unit 7 is designed as a rigid cylindrical tube structure. This structure improves the accuracy and sensitivity of temperature acquisition, shortens the temperature response time, and at the same time enhances the stability and durability of the temperature sensing unit 7. The rigid structure can better resist the influence of the internal environment of the battery, reduce the risk of deformation and damage, and thus ensure long-term stable temperature measurement performance.

[0064] Among them, in this application, the steps of preparing the built-in multi-sensor device are as follows:

[0065] (1) Combine two wires 1 with insulating coatings 2 attached to partial areas with the temperature sensing unit 7;

[0066] (2) Fix two spacers 4 at the upper and lower ends of the pressure sensing unit 6 respectively, and combine the other two wires 1 with insulating coatings 2 attached to partial areas with the pressure sensing unit 6;

[0067] (3) Fix the temperature sensing unit 7 and the pressure sensing unit 6 obtained in step (1) and step (2) in the flexible encapsulation layer 3;

[0068] (4) Combine the flexible encapsulation layer 3 with the sealing plug 5;

[0069] (5) Lead out the four wires 1 with insulating coatings 2 from the sealing plug 5, and combine the insulating coatings 2 with the sealing plug 5.

[0070] Among them, in this application, the steps of putting the built-in multi-sensor device into the battery are as follows:

[0071] (1) Insert the built-in multi-sensor device into the cylindrical battery along the axial direction of the liquid injection hole until the sealing plug 5 contacts the stainless steel shell of the cylindrical battery;

[0072] (2) Combine the sealing plug 5 with the stainless steel shell of the cylindrical battery by using a welding process or an adhesive process.

[0073] Thus, the built-in multi-sensor device can be firmly combined with the cylindrical battery, ensuring that the pressure and temperature output signals can be stably read by the signal collector outside the cylindrical battery through the wire 1.

[0074] The above description is only for the embodiments of this application and is not intended to limit the protection scope of this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. An in-built multi-sensor device for detecting the safety of cylindrical batteries, characterized in that, It includes at least a pressure sensing unit (6), a temperature sensing unit (7), a separator (4), and a flexible encapsulation layer (3) built into the cylindrical battery. The pressure sensing unit (6) is in the form of a flexible cylindrical block, which is used to collect the pressure within the cylindrical battery in the range of 360° directions. The separator (4) is fixed at both ends of the pressure sensing unit (6) to prevent the pressure sensing unit (6) from undergoing axial deformation due to the influence of temperature. The temperature sensing unit (7) is arranged at intervals on one side of the pressure sensing unit (6) and is used to collect the temperature inside the cylindrical battery. The pressure sensing unit (6), the temperature sensing unit (7), and the separator (4) are encapsulated in the flexible encapsulation layer (3). The flexible encapsulation layer (3) is used to isolate the electrolyte and is in close contact with the pressure sensing unit (6) and the temperature sensing unit (7), shortening the response time of the pressure sensing unit (6) and the temperature sensing unit (7).

2. The built-in multi-sensor device for detecting the safety of cylindrical batteries according to claim 1, wherein Sealing plugs (5) are provided at both ends of the cylindrical battery. The sealing plugs (5) are used to prevent the leakage of the electrolyte and at the same time prevent it from seeping into the pressure sensing unit and the temperature sensing unit.

3. The built-in multi-sensor device for detecting the safety of cylindrical batteries according to claim 2, wherein The built-in multi-sensor device further includes wires (1). There are multiple wires (1), and the multiple wires (1) are arranged at intervals. One end is connected to the temperature sensing unit (7) or the pressure sensing unit (6), and the other end extends outward through the sealing plug (5) to be connected to a signal collector. The wires (1) are used to transmit the battery temperature information collected by the temperature sensing unit (7) and the battery pressure information collected by the pressure sensing unit (6).

4. The built-in multi-sensor device for detecting the safety of cylindrical batteries according to claim 3, characterized in that, Taking the extension direction of the wire (1) as the upper side, the pressure sensing unit (6) is arranged below the temperature sensing unit (7).

5. An internal multi-sensor device for detecting the safety of cylindrical batteries according to claim 4, characterized in that, The temperature sensing unit (7) is in the form of a cylindrical tube with a hollow through-hole inside.

6. The built-in multi-sensor device for detecting the safety of cylindrical batteries according to claim 5, characterized in that, The wire (1) connected to the pressure sensing unit (6) extends outward through the hollow through-hole of the temperature sensing unit (7), avoiding interference with the battery pressure information when transmitting the battery temperature information.

7. An internal multi-sensor device for detecting the safety of cylindrical batteries according to claim 6, characterized in that, The wires (1) connected to the temperature sensing unit (7) are arranged at intervals on the inner wall of the hollow through-hole and extend outward.

8. An internal multi-sensor device for detecting the safety of cylindrical batteries according to claim 7, characterized in that, Insulating coatings (2) are coated on the multiple wires (1), and the insulating coatings are fixedly connected to the sealing plug (5).

9. The built-in multi-sensor device for detecting the safety of cylindrical batteries according to claim 1, characterized in that, The separator (4) is a rigid cylindrical sheet.

10. The built-in multi-sensor device for detecting the safety of cylindrical batteries according to claim 1, characterized in that, The temperature sensing unit (7) is a rigid cylindrical tube.

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