Temperature detection system of liquid cooling energy storage battery and accelerated aging test method

Abstract

The invention provides a temperature detection system of a liquid cooling energy storage battery and an accelerated aging test method, and belongs to the technical field of battery accelerated aging tests. The temperature detection system comprises an implantable thermoelectric sensing device and a processing device. The implantable thermoelectric sensing device comprises an internal electrode, an external electrode and a thermoelectric material part; the internal electrode is embedded into a battery cell of the energy storage battery and consists of a plurality of layers of graphite materials; the external electrode is immersed in a liquid cooling agent of the energy storage battery and is composed of a metal Cu elementary substance; the thermoelectric material part is connected between the internal electrode and the external electrode and is composed of three layers of SnSe; the processing device is electrically connected with the internal electrode and the external electrode, and is used for obtaining a thermoelectric signal of the implantable thermoelectric sensing device. The implantable thermoelectric sensor is embedded into the energy storage battery, in-situ, real-time and accurate internal temperature monitoring can be achieved in the accelerated aging process of the energy storage battery, and the safety of management application of the energy storage battery can be remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery accelerated aging tests, and in particular relates to a temperature detection system and an accelerated aging test method for a liquid-cooled energy storage battery. Background Art

[0002] Accelerated battery aging testing, without changing the battery failure mechanism, studies the relationship between battery life decay and accelerated stress conditions, establishing a mapping between accelerated testing and actual usage scenarios. This allows for accurate estimation of the battery's service life and performance under normal operating conditions. Accurately monitoring the battery's internal temperature during aging testing allows for analysis of the temperature's changing patterns and evolution, improving the accuracy of battery life assessments.

[0003] The internal temperature detection of the battery is mainly achieved through implantable sensors. Currently, implantable optical fibers, thermocouples and other sensors are mostly used. However, these implantable sensors will destroy the integrity of the electrodes, and are not manufactured for the complex electrolyte corrosion environment inside the battery. They are prone to problems such as short sensor life and inaccurate data collection. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a temperature detection system and an accelerated aging test method for a liquid-cooled energy storage battery in view of the deficiencies in the prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A temperature detection system for a liquid-cooled energy storage battery, comprising an implantable thermoelectric sensing device and a processing device; The implantable thermoelectric sensor device includes an internal electrode, an external electrode, and a thermoelectric material portion; the internal electrode is embedded in the battery cell of the energy storage battery and is composed of multiple layers of graphite material; the external electrode is immersed in the liquid coolant of the energy storage battery and is composed of a single metal Cu; the thermoelectric material portion is connected between the internal electrode and the external electrode and is composed of three layers of SnSe; The thermoelectric material portion is composed of a first material layer and a second material layer, the first material layer is a single layer of SnSe, and the second material layer is a double layer of SnSe; when the internal electrode and the external electrode are connected to the thermoelectric material portion, the internal electrode and the external electrode are both located between the first material layer and the second material layer; The processing device is electrically connected to the internal electrode and the external electrode, and is used to obtain the thermoelectric signal of the implantable thermoelectric sensing device.

[0006] Further, the processing device is configured to obtain the temperature difference between the energy storage battery cell and the liquid coolant according to the mapping relationship between the thermoelectric signal and the temperature difference, and is configured to obtain the internal temperature of the energy storage battery cell according to the temperature difference and the temperature of the liquid coolant.

[0007] Further, the processing device is configured to obtain the self-generated heat of the energy storage battery during a complete charge-discharge cycle; the natural heat , where n is the number of time periods into which the complete charge-discharge cycle is split according to the change in the internal temperature of the battery cell, and T i represents the internal temperature of the battery cell in the i-th time period, and t i represents the duration of the i-th time period.

[0008] Further, the processing device is configured to detect the thermoelectric performance of the thermoelectric material in the thermoelectric material part under different stress actions.

[0009] Further, the processing device is configured to detect the relationship between the thermoelectric performance of the thermoelectric material in the thermoelectric material part and the temperature of the liquid coolant under different temperature differences and different stress actions.

[0010] Further, the processing device is configured to detect the temperature rise characteristics and sensitivity of the thermoelectric material in the thermoelectric material part under different stress actions.

[0011] Further, the stress actions include transverse tension, longitudinal tension, and bending.

[0012] Further, the processing device is configured to calibrate the mapping relationship between the thermoelectric signal and the temperature difference.

[0013] An accelerated aging test method for a liquid-cooled energy storage battery, implemented by using the temperature detection system, includes: Performing an accelerated aging test on the liquid-cooled energy storage battery by using accelerated stress test indexes; Real-time collecting the temperature data of the liquid coolant and the thermoelectric signals of the implantable thermoelectric sensing device; Obtaining the temperature difference data between the inside of the battery and the liquid coolant according to the thermoelectric signals of the implantable thermoelectric sensing device; Obtaining the internal temperature data of the battery according to the temperature difference data and the temperature data of the liquid coolant; Evaluating the battery life according to the accelerated aging test data and the change of the internal temperature data of the battery.

[0014] Further, the accelerated stress test indexes include several of temperature, charge-discharge rate, state of charge, charge-discharge depth, cut-off voltage, etc.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The implantable thermoelectric sensor device of the present invention comprises an internal electrode, an external electrode, and a thermoelectric material portion. The internal electrode is embedded within the cell of an energy storage battery and is composed of graphite. The external electrode is immersed in the battery's coolant and is composed of metallic silver. The thermoelectric material portion, connected between the internal and external electrodes, consists of three layers of SnSe. The graphite internal electrode is suitable for the complex, corrosive electrolyte environment within the battery. The three-layer SnSe thermoelectric material, combined with the internal electrode, can be embedded within the battery, achieving lossless sensor integration. This avoids issues associated with other implantable sensors, such as fiber optics, such as electrode integrity loss, poor battery sealing, electrode damage, and battery life impairment. It also increases battery capacity and lifespan. The three-layer SnSe thermoelectric material employed in the present invention exhibits stable thermoelectric performance, with minimal impact from changes in coolant temperature and stress. Furthermore, it exhibits high sensing sensitivity, with a response intensity at ΔT = 100K 200 times greater than at ΔT = 1K (at a coolant temperature of 300K), resulting in superior sensing performance.

[0016] The implantable thermoelectric sensor of the present invention is embedded in the interior of the energy storage battery, and can realize in-situ, real-time and accurate internal temperature monitoring during the accelerated aging process of the energy storage battery, avoiding the problems of poor accuracy and hysteresis when other types of sensors detect temperature. It is more valuable for reference to the thermal management of energy storage batteries and can significantly improve the safety of energy storage battery management applications.

[0017] The implantable thermoelectric sensor of the present invention is based on a passive sensing mechanism, and has a small size, good stability, and the advantages of long-term, low-consumption, stable, and lossless operation. It has broad prospects in the field of long-term, stable, and safe management of energy storage batteries.

[0018] The present invention can establish a stable and repeatable mapping relationship between the internal temperature changes and electrical signals during the accelerated aging process of energy storage batteries, providing more accurate and reliable parameters for the accelerated aging analysis of energy storage batteries and offering a new reference for the study of their internal evolution mechanism.

[0019] The present invention can measure the self-generated heat of an energy storage battery during a complete charge and discharge cycle. By obtaining the self-generated heat of the battery during a complete charge and discharge cycle and comparing the self-generated heat of the battery under different states, the aging state of the battery can be evaluated, the performance degradation and aging characteristics of the battery can be measured, and accelerated aging experiments can be performed to accelerate performance evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described in further detail below with reference to the accompanying drawings.

[0021] Figure 1 : A schematic structural diagram of embodiment 1 of the present invention; Figure 2 : Schematic diagram of an implantable thermoelectric sensor according to embodiment 1 of the present invention; Figure 3 : Schematic diagram of the change of heat generation power of the battery under different cycle numbers; Figure 4 : Schematic diagram of the failure mechanism of lithium iron phosphate batteries; Figure 5 : Schematic diagram of the changes in the energy band gap and electron transport characteristics of three-layer SnSe thermoelectric materials; Figure 6 : Schematic diagram of the performance of three-layer SnSe under different stress conditions and different temperature differences; Figure 7 : Schematic diagram of the relationship between the thermal sensing current and temperature difference of three-layer SnSe; Figure 8 : Schematic diagram of self-heat generation of energy storage batteries in different aging states during the charge and discharge cycle; Among them: 1- implantable thermoelectric sensor device, 11- internal electrode, 12- external electrode, 13- thermoelectric material part, 2- processing device. DETAILED DESCRIPTION

[0022] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the examples and drawings, but the protection content of the present invention is not limited to the following examples. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0023] Example 1: See Figures 1-8 The purpose of this embodiment is to provide a temperature detection system for a liquid-cooled energy storage battery, including an implantable thermoelectric sensor 1 and a processing device 2.

[0024] Specifically, the implantable thermoelectric sensor device 1 includes an internal electrode 11, an external electrode 12, and a thermoelectric material portion 13. The internal electrode 11 is composed of multiple layers of graphite and is directly embedded in the battery cell. The external electrode is composed of a single element of Cu and is directly immersed in the battery's coolant. The thermoelectric material portion 13 is connected between the internal and external electrodes 11 and 12 and is composed of three layers of SnSe.

[0025] like Figure 2 As shown, the three-layer SnSe structure of the thermoelectric material portion 13 is specifically composed of a first material layer and a second material layer. The first material layer is a single layer of SnSe, and the second material layer is a double layer of SnSe. When the internal electrode 11 and the external electrode 12 are connected to the thermoelectric material portion 13, the internal electrode 11 and the external electrode 12 are both located between the first and second material layers and connected to the first and second material layers.

[0026] When the signal is transmitted from the internal electrode 11 to the external electrode 12, compared with other single-layer or double-layer thermoelectric materials, the signal intensity of the three-layer SnSe structure of the present invention will be stronger. At the same time, due to the increase in the signal transmission channels, the signal acquisition speed will be faster. In addition, since the transmission channels of the first material layer and the second material layer are different, but they exist in the same usage environment, the signal intensities of the first material layer and the second material layer will remain near a fixed ratio. Therefore, by detecting the ratio change of the signal intensities of the first material layer and the second material layer, the stability and reliability of the implantable thermoelectric sensing device 1 can be judged, and high-quality signal acquisition and data collation can be achieved.

[0027] The processing device 2 is electrically connected to the internal electrode 11 and the external electrode 12. When there is a temperature difference (ΔT) between the internal temperature of the battery cell and the temperature of the liquid coolant, it will drive the phenomenon of charged particles diffusing from the high-temperature region to the low-temperature region in the thermoelectric material part 13. Since a closed loop is formed between the processing device 2 and the internal electrode 11 and the external electrode 12, the processing device 2 can monitor the thermoelectric signal. And there is a certain mapping relationship between the thermoelectric signal and the temperature difference. Therefore, the processing device 2 can monitor the temperature difference inside and outside the battery in real time according to the mapping relationship between the thermoelectric signal and the temperature difference. The temperature of the external coolant can be monitored in real time, and the temperature inside the battery can be obtained in real time. By monitoring the real temperature inside the battery cell in real time and accurately, the change process of the internal temperature of the battery cell during the accelerated aging process of the battery can be tracked, and the change of the internal temperature of the energy storage battery under different external stress conditions such as high temperature, low temperature, overcharge, over-discharge, and high-rate charge and discharge can be sensed and quantified. Furthermore, the relationship between the internal temperature of the battery and the accelerated aging of the battery can be constructed.

[0028] The heat generation of the positive and negative electrodes of the battery is composed of three parts: polarization heat, reaction heat, and ohmic heat. Along with multiple charge and discharge cycles of the battery, side reactions in the battery will cause loss of active substances inside it, and at the same time its internal resistance increases, thus changing the heat release characteristics of the battery, such as Figure 3 As shown in the heat generation power change of the battery under different cycle numbers, after the battery undergoes 2000 and 4000 charge and discharge cycles, the total heat generation power of the negative electrode of the battery increases significantly; at the same time, due to the growth of the SEI film generated by side reactions on the negative electrode, the heat generation power of the positive electrode of the battery remains almost unchanged. Therefore, the total heat generation power of the battery gradually increases with the increase of the battery aging degree. As Figure 4For the working failure mechanism of lithium iron phosphate batteries, the process of battery safety failure generally goes through five stages: normal operation - internal defects - thermal runaway trigger - exhaust - fire. The T1 temperature of most lithium-ion batteries is in the range of 70 - 150 °C (343 - 423 K), and most T2 are below 300 °C (573 K). Battery accelerated aging is carried out without changing the aging failure mechanism, and the battery is controlled below the temperature T2 at which the safety valve opens during the accelerated aging process. Therefore, the temperature for subsequent thermoelectric performance testing of the thermoelectric material part 13 refers to the safety temperature during the accelerated aging process.

[0029] The processing device 2 is also used to detect the thermoelectric performance of the thermoelectric material in the thermoelectric material part 13 under different stress conditions. Specifically, as Figure 5 shown, the three-layer SnSe thermoelectric material is respectively subjected to transverse tension, longitudinal tension and bending, and the processing device 2 is used to monitor the corresponding thermoelectric signals respectively.

[0030] The processing device 2 is also used to detect the relationship between the thermoelectric performance of the thermoelectric material in the thermoelectric material part 13 and the temperature of the liquid coolant at different temperature differences. Specifically, typical temperature differences (ΔT) of 5 K, 15 K and 25 K are selected, and the internal electrode 11 and the external electrode 12 are under different typical temperature differences. The processing device 2 is used to monitor the thermoelectric signals of the three-layer SnSe at different temperature differences, and the thermoelectric signals when different stresses are superimposed at different temperature differences. As Figure 6 shown is the performance of the three-layer SnSe under different stress conditions and different temperature differences, where Figure 6 -a, Figure 6 -b, Figure 6 -c are respectively the relationships between the thermoelectric current signals and the liquid coolant temperature under the conditions of transverse tension and bending stress, and when ΔT is 5 K, 15 K and 25 K respectively; Figure 6 -e, Figure 6 -f, Figure 6 -g are respectively the relationships between the thermoelectric current signals and the liquid coolant temperature under the conditions of longitudinal tension and bending stress, and when ΔT is 5 K, 15 K and 25 K respectively. When ΔT is 5 K, 15 K and 25 K respectively, the thermoelectric signals of the three-layer SnSe thermoelectric material do not increase significantly with the increase of the ambient temperature. In addition, the effects of transverse tension, longitudinal tension and bending on the performance of the three-layer SnSe are weak, and only transverse compression has a relatively obvious enhancing effect on the current. The results show that the thermoelectric current caused by the electrode temperature difference of the three-layer SnSe can still exhibit excellent thermoelectric stability under external strain, the thermoelectric performance of the three-layer SnSe thermoelectric material is stable, and the changes in the liquid coolant temperature and stress have very weak effects on its thermoelectric performance.

[0031] The processing device 2 is also used to detect the temperature rise characteristics and sensitivity of the thermoelectric material in the thermoelectric material part 13. Specifically, the temperature of the liquid coolant is maintained at 300K and 330K respectively, and the processing device 2 is used to monitor the thermoelectric signals at different temperature differences under different liquid coolant temperatures. As Figure 7 shown in the relationship between the thermal sensing current and the temperature difference ΔT when the liquid coolant temperature is 300K and 330K. The experiment shows that the thermal current will increase with the increase of ΔT, and compared with 300K, the signal change at 330K is more significant, which indicates that the GeP3 sensor has better sensitivity to the change of ΔT. In addition, when the liquid coolant temperature is 300K, the response intensity of the thermal sensor device at ΔT = 100K is nearly 200 times that at ΔT = 1K, which indicates that the three-layer SnSe has excellent sensitivity. As Figure 7 -a and Figure 7 -b show that even when the temperature difference inside and outside the battery is very small, when the device is laterally compressed by 6%, a large thermoelectric induction current can still be obtained. In addition, the influence of lateral stretching or small curvature bending on the signal sensitivity is also very weak, which confirms the robustness of the thermoelectric material. Figure 7 -c and Figure 7 -d show the influence of longitudinal strain on the sensitivity of the thermoelectric material to the liquid coolant temperature under the same temperature difference. The higher the liquid coolant temperature, the greater the response current of the thermoelectric device. When the temperature difference at both ends of the sensor device is the same, the higher the liquid coolant temperature, the higher the sensitivity. This advantage helps the detection device to obtain temperature signals more easily, and with the increase of the liquid coolant temperature, the characteristic of higher sensitivity will be more conducive to the monitoring of the aging process of large-capacity energy storage batteries.

[0032] The processing device 2 is also used to calibrate the mapping relationship between the thermoelectric signal and the temperature difference of the implantable thermoelectric sensing device 1. Based on the above experimental data, an accurate mapping relationship between the thermoelectric signal and the temperature difference can be obtained, making the monitoring of the internal temperature of the battery by the processing device 2 more accurate.

[0033] Generally speaking, the influence of stress changes (lateral stretching, longitudinal stretching and bending) on the thermoelectric performance of the thermoelectric material part 13 of the three-layer SnSe is small, and the thermoelectric material part 13 can be applied to the expansion and contraction during the charge and discharge process of the energy storage battery. When the temperature difference is close to 100K, its thermoelectric response is nearly 200 times higher than the steady state. The thermoelectric material part 13 has excellent sensitivity and stability, and can be used for the internal temperature monitoring during the aging process of the liquid-cooled energy storage battery.

[0034] The processing device 2 is also used to obtain the self-generated heat of the energy storage battery during a complete charge and discharge cycle. According to the detected temperature change of the battery cell, the complete charge and discharge cycle is divided into n time periods, then the self-generated heat , where T i represents the battery temperature in the i-th time period, and t iIndicates the duration of the i-th period.

[0035] As the battery ages, the internal resistance of the energy storage battery will gradually increase, which directly affects the heat generation of the battery during the charging and discharging process. The temperature of the energy storage battery during the charging process tends to rise first and then fall. The main reason for the rising process is the increase in heat generation during the constant current charging process, and the greater the rate, the greater the temperature peak and the rate of rise; the falling process corresponds to the constant voltage charging process, the rate has less effect on heat generation, and the temperature shows the same decreasing pattern. This shows that in the constant current charging stage, the battery temperature will rise rapidly, and in the constant voltage charging stage, the battery temperature will gradually decrease due to the decrease in current. Figure 8 The figure shows the self-generated heat of the energy storage battery during the charge and discharge cycle under different aging conditions. The self-generated heat in the initial state of the battery is represented as S1, the self-generated heat during normal aging is represented as S2, and the self-generated heat during accelerated aging is represented as S3. By comparing the changes in S1 and S2, the battery aging condition can be evaluated, and the changes in S1 and S3 can be used to evaluate the impact of different accelerated aging conditions on battery heat generation.

[0036] Therefore, by obtaining the self-heat generated by the battery during a complete charge and discharge cycle and comparing the self-heat generated by the battery under different states, it is possible to assess the battery aging state, measure the battery performance degradation and aging characteristics, and conduct accelerated aging experiments to accelerate performance assessment. Battery aging will cause the battery's thermal characteristics to change accordingly. Accurately detecting the internal temperature of energy storage batteries during the accelerated aging process can better capture the internal changes during the aging process, analyze the trend of changes, and evaluate the accelerated aging or degradation characteristics of energy storage battery performance. This provides direction for subsequent research on thermal management of energy storage batteries based on internal heat generation, supports accelerated aging tests of energy storage batteries, and can also prevent or reduce the risk of thermal runaway during the accelerated aging process of energy storage batteries, improving battery safety.

[0037] Example 2: The purpose of this example is to provide an accelerated aging test method for liquid-cooled energy storage batteries, which is implemented using Example 1. The method includes: Accelerated stress test indicators are used to conduct accelerated aging tests on liquid-cooled energy storage batteries; Real-time collection of liquid coolant temperature data and thermoelectric signals from implantable thermoelectric sensing devices; Acquiring temperature difference data between the interior of the battery and the liquid coolant based on a thermoelectric signal from an implantable thermoelectric sensor device; Acquire internal temperature data of the battery according to the temperature difference data and the liquid coolant temperature data; Evaluate battery life based on accelerated aging test data and changes in battery internal temperature data.

[0038] The accelerated stress test indicators include temperature, charge and discharge rate, state of charge, charge and discharge depth, and cut-off voltage.

[0039] The change law of the internal temperature during the accelerated aging of the battery can be obtained by the processing device 2.

[0040] The accelerated aging test accelerates the degradation of the product by making the liquid-cooled energy storage battery under more severe working conditions than normal use, and can evaluate the battery life under different stress conditions. By testing the battery aging behavior at different accelerated stress levels, the threshold value at which the battery degradation mode changes significantly can be found. Use an empirical or semi-empirical model to fit the battery decay curve within an appropriate stress range, and then obtain a life prediction model based on accelerated aging. The life prediction model can be used to evaluate the battery life by combining the accelerated aging experimental data and the battery internal temperature data.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Any other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A temperature detection system for a liquid-cooled energy storage battery, characterized in that, Includes an implantable thermoelectric sensing device and a processing device; The implantable thermoelectric sensor device includes an internal electrode, an external electrode, and a thermoelectric material portion; the internal electrode is embedded in the battery cell of the energy storage battery and is composed of multiple layers of graphite material; the external electrode is immersed in the liquid coolant of the energy storage battery and is composed of a single metal Cu; the thermoelectric material portion is connected between the internal electrode and the external electrode and is composed of three layers of SnSe; The thermoelectric material portion is composed of a first material layer and a second material layer, the first material layer is a single layer of SnSe, and the second material layer is a double layer of SnSe; When the internal electrode and the external electrode are connected to the thermoelectric material portion, the internal electrode and the external electrode are both located between the first material layer and the second material layer; The processing device is electrically connected to the internal electrode and the external electrode, and is used to obtain the thermoelectric signal of the implantable thermoelectric sensing device.

2. The temperature detection system of the liquid-cooled energy storage battery according to claim 1, characterized in that, The processing device is used to obtain the temperature difference between the energy storage battery cell and the liquid coolant based on the mapping relationship between the thermoelectric signal and the temperature difference, and is used to obtain the internal temperature of the energy storage battery cell based on the temperature difference and the temperature of the liquid coolant.

3. The temperature detection system for the liquid-cooled energy storage battery according to claim 2, wherein The processing device is used to obtain the self-generated heat of the energy storage battery during a complete charge-discharge cycle; the natural heat , where n is the number of time periods into which the complete charge-discharge cycle is split according to the internal temperature change of the battery cell, and T i represents the internal temperature of the battery cell in the i-th time period, and t i represents the duration of the i-th time period.

4. The temperature detection system of the liquid-cooled energy storage battery according to claim 1, characterized in that, The processing device is used to detect the thermoelectric performance of the thermoelectric material in the thermoelectric material portion under different stresses.

5. The temperature detection system of the liquid-cooled energy storage battery according to claim 1, characterized in that The processing device is used to detect the relationship between the thermoelectric performance of the thermoelectric material in the thermoelectric material portion and the temperature of the liquid coolant under different temperature differences and different stresses.

6. The temperature detection system of the liquid-cooled energy storage battery according to claim 1, wherein The processing device is used to detect the temperature rise characteristics and sensitivity of the thermoelectric material in the thermoelectric material portion under different stresses.

7. The temperature detection system for the liquid-cooled energy storage battery according to any one of claims 4-6, characterized in that, The stress effects include transverse stretching, longitudinal stretching and bending.

8. The temperature detection system of the liquid-cooled energy storage battery according to claim 1, characterized in that, The processing device is used to calibrate the mapping relationship between the thermoelectric signal and the temperature difference.

9. An accelerated aging test method for a liquid-cooled energy storage battery, implemented by using the temperature detection system according to any one of claims 1-8, characterized in that, include: Accelerated stress test indicators are used to conduct accelerated aging tests on liquid-cooled energy storage batteries; Real-time collection of liquid coolant temperature data and thermoelectric signals from implantable thermoelectric sensing devices; Acquiring temperature difference data between the interior of the battery and the liquid coolant based on a thermoelectric signal from an implantable thermoelectric sensor device; Acquire internal temperature data of the battery according to the temperature difference data and the liquid coolant temperature data; Evaluate battery life based on accelerated aging test data and changes in battery internal temperature data.

10. The temperature detection method of the liquid-cooled energy storage battery according to claim 9, characterized in that, The accelerated stress test indicators include several of temperature, charge and discharge rate, state of charge, charge and discharge depth, and cut-off voltage.

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