Synchronous detection device for multi-mode thermal and mass characteristics of lithium battery

Abstract

The utility model relates to the technical field of lithium batteries, and discloses a lithium battery multi-mode thermal mass characteristic synchronous detection device which comprises a split type double-cavity structure, an upper layer infrared detection cavity, a lower layer isothermal calorimetric cavity, a middle aerogel thermal insulation layer and an FPGA (Field Programmable Gate Array) control panel, a thermal infrared imager and a battery to be detected are arranged in the upper layer infrared detection cavity, and a lower layer isothermal calorimetric cavity is arranged in the lower layer isothermal calorimetric cavity. A thermopile array and an electromagnetic force weighing sensor are arranged in the lower-layer isothermal calorimetric cavity and used for obtaining heat production power and mass change, transverse heat flow is blocked by the aerogel heat insulation layer, millisecond-level synchronous triggering is achieved by the FPGA control panel, and the upper-layer cavity and the lower-layer cavity are connected through a low-heat-conduction ceramic column. The device solves the problems of thermal-mechanical coupling interference and multi-modal data loss of traditional detection equipment, and provides high-precision multi-physical field coupling data support for lithium battery thermal runaway early warning and health state evaluation.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a synchronous detection device for multimodal thermo-mass characteristics of lithium batteries. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage systems, the thermal safety and performance stability of lithium batteries have become a focus of industry attention. Currently, lithium battery testing mainly revolves around three core parameters: temperature field distribution, mass change, and heat generation characteristics. However, existing testing methods have many shortcomings, severely restricting the collaborative analysis of multi-modal parameters of lithium batteries.

[0003] While infrared thermal imaging technology can acquire battery surface temperature distribution through non-contact temperature measurement, it is susceptible to interference from environmental radiation and struggles to simultaneously monitor internal heat conduction. Weighing detection technology is used to monitor battery mass changes caused by electrolyte evaporation or SEI film formation, but traditional strain gauge load cells are easily affected by thermal expansion forces. Isothermal calorimetry uses thermopile or heat flow meters to measure battery heat generation power, but single-point temperature measurement cannot accurately reflect heat flow distribution characteristics. Furthermore, existing technologies suffer from thermo-mechanical coupling interference. For example, in traditional single-cavity designs, the thermal expansion forces generated during battery charging and discharging are directly transmitted to the load cell, leading to significant mass measurement errors. Meanwhile, thermal radiation from the infrared detection area is transmitted to the weighing unit through the support structure, causing sensor temperature drift. Simultaneously, asynchronous data acquisition in split-type devices makes it impossible to establish transient coupling relationships between temperature field, mass change, and heat generation power, and mismatched sampling rates between different sensors hinder data fusion. Additionally, conventional insulation materials (such as fiberglass) have high thermal conductivity, making it difficult to block lateral heat flow, and electromagnetic force load cells are susceptible to interference from FPGA high-frequency signals. Battery clamp obstruction leads to insufficient coverage of infrared thermal imager scanning, and the presence of multiple layers of contact thermal resistance between the thermopile and the battery affects the accuracy of heat generation power calculation. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a device for the synchronous detection of multimodal thermo-mass characteristics of lithium batteries.

[0005] To achieve simultaneous detection of the multimodal thermo-mass characteristics of the aforementioned lithium battery, this utility model provides the following technical solution:

[0006] A device for synchronous detection of multimodal thermo-mass properties of lithium batteries, comprising:

[0007] The upper detection chamber is used to acquire the surface temperature field distribution of the battery under test;

[0008] The lower detection chamber is used to acquire the heat generation power and mass change of the battery under test;

[0009] A heat insulation layer is disposed between the upper detection chamber and the lower detection chamber to block lateral heat exchange;

[0010] The control unit is used to realize the synchronous triggering of the detection devices in the upper and lower detection cavities.

[0011] The supporting connecting component is used to connect the upper detection chamber and the lower detection chamber, and to transmit the thermal and force signals of the battery under test.

[0012] Furthermore, the upper detection cavity includes an infrared thermal imager and a blackbody radiation source. The infrared thermal imager is used to acquire the surface temperature field distribution of the battery under test, and the blackbody radiation source is used to calibrate the infrared thermal imager.

[0013] Furthermore, the surface of the upper detection cavity is made of zinc selenide coated glass to reduce reflection loss and ensure that the infrared signal penetrates without distortion.

[0014] Furthermore, the lower detection chamber includes a thermopile array and an electromagnetic force weighing sensor. The thermopile array is used to measure the heat generation power of the battery under test, and the electromagnetic force weighing sensor is used to measure the mass change of the battery under test.

[0015] Furthermore, the heat insulation layer is made of aerogel material, which effectively blocks lateral heat flow and ensures thermal isolation between the upper and lower detection chambers.

[0016] Furthermore, the control unit is an FPGA control board, which is used to achieve millisecond-level synchronous triggering of the infrared thermal imager, electromagnetic force weighing sensor and thermopile, to ensure the synchronization and accuracy of data acquisition.

[0017] Furthermore, the supporting connection component includes a low thermal conductivity ceramic column, which is used to connect the upper detection chamber and the lower detection chamber and transmit the thermal and force signals of the battery under test, while reducing thermal-force coupling errors. The top of the low thermal conductivity ceramic column forms point contact with the titanium alloy clamp in the upper detection chamber through a hemispherical titanium alloy joint, and the bottom is connected to the electromagnetic force weighing sensor in the lower detection chamber through a flexible graphite gasket.

[0018] Furthermore, a ring-shaped thermopile array is arranged around the low thermal conductivity ceramic pillar at the top of the lower isothermal calorimeter cavity.

[0019] Furthermore, the electromagnetic force weighing sensor is surrounded by an annular temperature control cavity, which includes: a polyimide foam insulation layer, a four-wire platinum resistance thermometer for temperature monitoring, and a thin-film Peltier element for active temperature control.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. A split dual-cavity structure is adopted, which physically isolates the upper infrared detection layer from the lower isothermal calorimetry layer through a low thermal conductivity ceramic column, reducing thermal-mechanical coupling error and improving detection accuracy;

[0022] 2. The FPGA synchronously triggers the infrared thermal imager, weighing sensor and thermopile, and simultaneously realizes the coupled analysis of thermal expansion force-temperature field-heat generation power at the millisecond level, which shortens the detection time;

[0023] 3. The aerogel insulation layer and the low thermal conductivity ceramic column work together to suppress ambient temperature fluctuations, and the electromagnetic shielding design reduces external interference to the electromagnetic weighing sensor, thus enhancing the environmental interference suppression capability of the measurement system. Attached Figure Description

[0024] Figure 1 A schematic diagram of the structure of this utility model;

[0025] Figure 2 Explosion-proof diagram of the structure;

[0026] Figure 3 Detailed schematic diagram of a low thermal conductivity ceramic column;

[0027] Figure 4 Detailed schematic diagram of the hollowed-out titanium alloy clamp;

[0028] Figure 5 Detailed schematic diagram of the upper cavity;

[0029] Figure 6 Detailed schematic diagram of the lower cavity. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] Please see Figure 1-3 A multimodal lithium battery thermo-mass characteristics synchronous detection device includes an upper infrared detection cavity 7, a lower isothermal calorimetric cavity 9, an intermediate aerogel insulation layer 8, and an FPGA control board 18.

[0034] The upper infrared detection cavity houses an infrared thermal imager and the battery under test, used to acquire the surface temperature field distribution of the battery under test. The lower isothermal calorimetry cavity houses a thermopile array and an electromagnetic force weighing sensor, used to acquire the heat generation power and mass change of the battery under test. The intermediate aerogel insulation layer is used to block lateral heat exchange and prevent the upper temperature from affecting the accuracy of the lower weighing sensor. The FPGA control board is used to achieve millisecond-level synchronous triggering of the infrared thermal imager, weighing sensor, and thermopile.

[0035] like Figure 5 In this embodiment, the surface of the upper infrared detection cavity 7 is made of zinc selenide coated glass to reduce reflection loss and ensure that the infrared signal is transmitted without distortion. The window edge of the upper infrared cavity 7 is sealed with a fluororubber sealing ring to ensure the airtightness of the calorimeter chamber. An infrared thermal imager 1 and a stepper motor 2 that controls the up and down movement of the infrared thermal imager to perform full surface temperature field scanning are installed on the top of the upper cavity 7. A blackbody radiation source 14 is installed on the right cavity surface of the upper cavity 7 for periodically emitting standard signals to calibrate the infrared thermal imager. The battery under test 4 is placed below the axis of the infrared thermal imager 1. A titanium alloy clamp 5 is used as a heat conduction medium to clamp the battery under test. The titanium alloy clamp 5 also has a charging / discharging port 3. A flexible pad 6 is located below the titanium alloy clamp 5.

[0036] It should be noted that the titanium alloy fixture is coated with a high-emissivity matte iron oxide black coating using plasma spraying technology to enhance the diffuse reflection effect; furthermore, the titanium alloy fixture 5 is designed with a hollowed-out shape, such as... Figure 4 The side has a regular hexagonal cutout 31 with an opening rate of ≥70%, which maximizes the exposure of the battery surface and ensures that the infrared thermal imager can scan without obstruction. The annular array of air holes 32 at the bottom of the fixture ensures that the electrolyte volatile gas is discharged.

[0037] In this embodiment, an aerogel insulation layer 8 is provided between the upper infrared detection cavity 7 and the lower isothermal calorimetry cavity 9 for filling, and insulation layer holes 10 are reserved in the aerogel insulation layer 8.

[0038] It should be noted that the reserved insulation layer hole 10 is wrapped with a flexible insulation sleeve made of aluminum silicate fiber to cover the contact section between the low-conductivity ceramic column 11 and the aerogel insulation layer 8, thus blocking lateral heat exchange.

[0039] In this embodiment, the low thermal conductivity ceramic column 11 penetrates the aerogel insulation layer 8 and the lower isothermal calorimetric cavity 9, and the top of the low thermal conductivity ceramic column 11 forms a point contact with the titanium alloy clamp 5 through a hemispherical titanium alloy joint.

[0040] It should be noted that the ceramic column 11 is made of zirconia ceramic, and the hemispherical titanium alloy at the top reduces lateral force interference and forms the only vertical force transmission channel. The low thermal conductivity ceramic column 11 serves as the only heat flow path to conduct the heat generated by the battery from the upper titanium alloy clamp 5 to the annular array thermopile 12 at the top of the lower isothermal calorimeter cavity for temperature measurement. By increasing the aspect ratio, the axial thermal resistance is improved, so that the heat generated by the battery can be transferred to the annular array thermopile 12 more efficiently.

[0041] In this embodiment, a ring-shaped thermopile array 12 is arranged around the low thermal conductivity ceramic column 11 at the top of the lower isothermal calorimetric cavity 9, and the bottom low thermal conductivity ceramic column 11 is equipped with a temperature compensation module 13, which calculates the heat flow by measuring the axial temperature gradient of the ceramic column.

[0042] It should be noted that the toroidal thermopile array 12 is specifically as follows: Figure 3 As shown, the thermopile is attached to the low thermal conductivity ceramic column 11 (top of the lower isothermal calorimeter cavity 9) in a concentric circle pattern, with a total of 3 concentric rings. Each layer has 12 pairs of K-type thermocouples, with a 15° spiral angle and 60° staggered distribution in each layer. The phase difference between thermocouple nodes between adjacent layers is 30° to optimize heat flow vector detection.

[0043] like Figure 6 As shown, in this embodiment, an electromagnetic force weighing sensor 15 is placed at the bottom of the lower isothermal calorimetric cavity 9. The electromagnetic force weighing sensor 15 is connected to the lower end of the low thermal conductivity ceramic column 11 through a flexible graphite pad 21. An annular temperature control cavity 19 is provided around the electromagnetic force weighing sensor 15.

[0044] It should be noted that, in order to avoid weighing drift caused by temperature gradients, the annular temperature control cavity 19 is composed of a heat insulation layer 16, a four-wire platinum resistance thermometer 20, and a thin-film Peltier element 17; wherein the heat insulation layer 16 is polyimide foam; the four-wire platinum resistance thermometer 20 and the thin-film Peltier element 17 are symmetrically distributed around the sensor, thereby isolating external ambient temperature fluctuations and improving the accuracy of the weighing sensor.

[0045] In this embodiment, an FPGA control board 18 is installed on the outside of the side wall of the lower isothermal calorimeter chamber 9. The FPGA control board 18 realizes millisecond-level synchronous triggering of the infrared thermal imager, weighing sensor and thermopile, thereby improving detection accuracy.

[0046] It should be noted that the FPGA control board 18 is located in an independent metal shielded cavity 22 to avoid interference from the FPGA's high-frequency signals to the weighing sensor and thermopile.

[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for synchronous detection of multimodal thermo-mass characteristics of lithium batteries, characterized in that, include: The upper detection chamber is used to acquire the surface temperature field distribution of the battery under test; The lower detection chamber is used to acquire the heat generation power and mass change of the battery under test; A heat insulation layer is disposed between the upper detection chamber and the lower detection chamber to block lateral heat exchange; The control unit is used to realize the synchronous triggering of the detection devices in the upper and lower detection cavities. The supporting connecting component is used to connect the upper detection chamber and the lower detection chamber, and to transmit the thermal and force signals of the battery under test.

2. The lithium battery multi-modal thermo-mass characteristic synchronous detection device according to claim 1, characterized in that, The upper detection cavity includes an infrared thermal imager and a blackbody radiation source. The infrared thermal imager is used to acquire the surface temperature field distribution of the battery under test, and the blackbody radiation source is used to calibrate the infrared thermal imager.

3. The lithium battery multi-modal thermal mass property synchronous detection device according to claim 1 or 2, characterized in that, The surface of the upper detection cavity is made of zinc selenide coated glass.

4. The lithium battery multimodal thermo-mass characteristic synchronous detection device according to claim 2, characterized in that, The lower detection chamber includes a thermopile array and an electromagnetic force weighing sensor. The thermopile array is used to measure the heat generation power of the battery under test, and the electromagnetic force weighing sensor is used to measure the mass change of the battery under test.

5. The lithium battery multi-modal thermo-mass characteristic synchronous detection device according to claim 1, characterized in that, The insulation layer is made of aerogel material.

6. The lithium battery multi-modal thermal mass property synchronous detection apparatus of claim 4, wherein, The control unit is an FPGA control board, which is used to realize millisecond-level synchronous triggering of the infrared thermal imager, electromagnetic force weighing sensor and thermopile.

7. The lithium battery multi-modal thermo-mass characteristic synchronous detection device according to claim 1, characterized in that, The supporting connection component includes a low thermal conductivity ceramic column, which is used to connect the upper detection chamber and the lower detection chamber and transmit the thermal and force signals of the battery under test, while reducing thermal-force coupling errors. The top of the low thermal conductivity ceramic column forms point contact with the titanium alloy clamp in the upper detection chamber through a hemispherical titanium alloy joint, and the bottom is connected to the electromagnetic force weighing sensor in the lower detection chamber through a flexible graphite gasket.

8. The lithium battery multimodal thermo-mass characteristic synchronous detection device according to claim 7, characterized in that, A ring-shaped thermopile array is arranged around the low thermal conductivity ceramic pillar at the top of the lower detection cavity.

9. The lithium battery multimodal thermo-mass characteristic synchronous detection device according to claim 4, characterized in that, The electromagnetic force weighing sensor is surrounded by an annular temperature control cavity, which includes: a polyimide foam insulation layer, a four-wire platinum resistance thermometer for temperature monitoring, and a thin-film Peltier element for active temperature control.

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