A device and method for measuring battery specific heat capacity based on ultrasound

Abstract

The present invention discloses an ultrasonic-based battery specific heat capacity measurement device and method, comprising an ultrasonic sensor, a microcontroller chip, a probe cable, a fixed upper bracket, a fixed lower bracket, and a coupling agent. The measuring device, which integrates a battery, is placed in a temperature-controllable environment to achieve temperature equilibrium of the battery at several temperatures. During this period, the ultrasonic sensor activates excitation and receives ultrasonic signals passing through the battery, and the microcontroller chip calculates and stores the time-of-flight offset of each measurement, and fits the relationship between the time-of-flight offset and temperature. AC pulse heating is applied to the temperature-equilibrated battery, while timed voltage and ultrasonic signal acquisition is simultaneously started. If the time-of-flight offset remains constant over a period of time, the AC pulse heating is stopped, and the battery is cooled to ambient temperature. The time-of-flight offset during the AC pulse heating-cooling phase is mapped to the battery temperature using a fitted relationship, and the specific heat capacity of the battery is calculated based on an energy conservation equation.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to an ultrasonic-based device and method for measuring the specific heat capacity of a battery. Background Art

[0002] Lithium-ion batteries, with their numerous advantages, including high energy density, long life, and lack of memory effect, are widely used in electric vehicle powertrains. Temperature is a critical battery condition that influences energy efficiency, aging rate, and safety. Excessively high temperatures can lead to a series of phenomena, including decomposition of the solid electrolyte interface film, anode-electrolyte reactions, and separator melting, ultimately causing thermal runaway. Low temperatures can affect battery energy efficiency, and high-rate charging at low temperatures can cause lithium deposition, directly impacting battery life and safety. Therefore, to maintain optimal performance, lithium-ion batteries must maintain a temperature between 15°C and 35°C. To this end, researchers typically apply battery thermal models to predict and control temperature. In these models, the specific heat capacity of the battery is a crucial parameter, directly influencing the temperature changes caused by the absorption and release of heat by the battery.

[0003] There are two main methods for measuring specific heat capacity: (1) Accelerated adiabatic calorimetry: Using a heating plate to heat the battery to be tested, the temperature of the inner wall of the accelerated adiabatic calorimeter tracks the temperature of the battery surface to create an approximately adiabatic environment; Based on the heating power of the heating plate and the temperature rise of the battery to be tested, the specific heat capacity of the battery to be tested is calculated using the ideal relationship between temperature rise and specific heat capacity; the disadvantage of this method is high cost. (2) Differential scanning calorimetry: This method places the sample to be tested and a reference material of known specific heat capacity in the same environment, and calculates the specific heat capacity of the sample to be tested based on the heat difference required to reach the same temperature; the disadvantage of this method is that it has strict requirements on the dosage of the sample to be tested, and is not suitable for measuring the specific heat capacity of batteries. Therefore, it is necessary to provide a new method for measuring the specific heat capacity of batteries. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of existing battery specific heat capacity measurement technology, and proposes a battery specific heat capacity measurement device and method based on ultrasound. The relationship between the flight time offset and temperature under different states of charge (SOC) is curve-fitted as the basis for ultrasonic estimation of battery temperature. The battery is subjected to AC pulse heating until its temperature is balanced, the heating is stopped, and the battery is cooled to ambient temperature; the flight time offset during the AC pulse heating-cooling phase is mapped to the battery temperature, and the law of conservation of energy is used to estimate the battery's external heat transfer thermal resistance and specific heat capacity in turn. The specific heat capacity measurement method proposed in the present invention effectively utilizes the temperature-sensitive property of ultrasound and can realize the measurement of the battery's specific heat capacity; compared with the traditional method of measuring specific heat capacity, a method based on ultrasound has the advantages of low cost and non-destructiveness.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A device for measuring the specific heat capacity of a battery based on ultrasound comprises an ultrasonic sensor, a microcontroller chip, a probe cable, a fixed upper bracket, a fixed lower bracket, and a coupling agent. The fixed upper bracket and the fixed lower bracket fix the ultrasonic sensor to the surface of a battery coated with the coupling agent, and the ultrasonic sensor is connected to the microcontroller chip via the probe cable. The ultrasonic sensor excites and receives ultrasonic signals passing through the battery, and communicates the collected signals to the microcontroller chip, which calculates and stores the time-of-flight offset.

[0007] Among them, the ultrasonic sensor depends on the specific measurement method; for transmitted wave measurement, the ultrasonic sensor includes a pair of ultrasonic pulse transmitting probes and ultrasonic pulse receiving probes, which are respectively fixed at the same position on the opposite sides of the battery; for reflected wave measurement, the ultrasonic sensor includes an ultrasonic pulse transmitting / receiving probe, which is fixed at any position on the battery surface; for guided wave measurement, the ultrasonic sensor includes a pair of ultrasonic pulse transmitting probes and ultrasonic pulse receiving probes, which are respectively fixed at both ends of the same surface of the battery.

[0008] The excitation pulse of the microcontroller chip to the ultrasonic sensor is a square wave or a cosine wave, etc., and the frequency range is 0.1-5MHz.

[0009] A method for measuring the specific heat capacity of a battery based on ultrasound comprises the following steps:

[0010] S1. Place the integrated battery measurement device in a temperature-controlled environment and achieve temperature balancing of the battery at several temperatures. During this time, the ultrasonic sensor activates and receives ultrasonic signals passing through the battery. The microcontroller chip calculates and stores the time-of-flight offset for each measurement and fits the relationship between the time-of-flight offset and temperature.

[0011] S2. Change the SOC of the battery multiple times and repeat the steps described in S1 to achieve the fitting of the flight time offset and temperature under multiple SOCs;

[0012] S3 applies AC pulse heating to the battery at a balanced temperature while simultaneously starting to collect the battery voltage and ultrasonic signals. If the flight time offset remains constant over a period of time, the AC pulse heating is stopped and the battery is cooled to ambient temperature.

[0013] S4. Map the flight time offset during the AC pulse heating-cooling phase to the battery temperature using a fitting relationship, and calculate the specific heat capacity of the battery based on the energy conservation equation.

[0014] The flight time offset calculation method includes but is not limited to the cross-correlation analysis method.

[0015] The step S1 includes the following sub-steps:

[0016] S101. The integrated battery measuring device is placed in a temperature-controlled environment and the battery is left standing for a sufficient period of time at any ambient temperature until the temperature is balanced;

[0017] S102. The ultrasonic sensor starts to excite and receive ultrasonic signals passing through the battery, and the microcontroller chip calculates and stores the flight time offset for each measurement;

[0018] S103. Change the ambient temperature multiple times and repeat sub-steps S101 and S102;

[0019] S104. Fit the temperature at several equilibrium moments and the corresponding flight time offsets, and the fitting formula includes but is not limited to:

[0020] ΔTOF=a1T+a0 (1)

[0021] Where ΔTOF is the time-of-flight offset, a1 and a0 are fitting coefficients, and T is the battery temperature. Formula (1) uses the ultrasonic time-of-flight offset to estimate the subsequent battery temperature when the initial battery temperature is known.

[0022] The step S3 includes the following sub-steps:

[0023] S301. The ambient temperature is set to any temperature allowed by the measuring device, the battery is left to stand for a period of time until the temperature is balanced, and the battery voltage and ultrasonic signal are collected;

[0024] S302. Select a discharge current to discharge the battery briefly, the SOC change during the discharge process does not exceed 5%, and then select a charge current to charge the battery briefly to restore the battery to the SOC before discharge;

[0025] S303. Repeat sub-step S302 several times to achieve AC pulse heating of the battery;

[0026] S304 . If the flight time offset remains constant for a period of time, stop AC pulse heating and allow the battery to cool to ambient temperature.

[0027] The step S4 includes the following sub-steps:

[0028] S401. During the AC pulse heating-cooling phase, the temperature change relative to the ambient temperature is calculated as follows:

[0029]

[0030] Where ΔTOF1 is the time-of-flight offset of the ultrasonic signal relative to the temperature equilibrium, and k is the rate of change of the time-of-flight offset with temperature (for fitting formula (1), k = a1); the battery temperature is obtained by adding the temperature change to the ambient temperature;

[0031] S402. During the constant flight time offset phase of AC pulse heating, the heat generated by the battery is equal to the heat dissipated. The external heat transfer thermal resistance of the battery is calculated as follows:

[0032]

[0033] Where T0 is the battery temperature during the constant flight time offset phase, T a is the ambient temperature, is the heat generation rate during the constant flight time offset phase, which is calculated as follows:

[0034]

[0035] Where V is the battery voltage during the constant flight time offset phase, V OCV is the voltage before AC pulse heating, I is the battery current;

[0036] S403. During the battery cooling process, the rate at which the battery's internal energy decreases is equal to the external heat exchange rate. Theoretically, the formula for how the battery's temperature changes over time is:

[0037]

[0038] Where m is the mass of the battery, C p is the specific heat capacity of the battery, t is the time of the cooling process; the battery temperature during the cooling process is curve fitted according to formula (5) to obtain the specific heat capacity C p .

[0039] The beneficial effects of the present invention are as follows: the present invention proposes an ultrasonic-based battery specific heat capacity measurement device and method, which performs ultrasonic measurement on the battery and calculates the flight time offset based on the collected ultrasonic data, thereby realizing the calculation of the battery temperature and specific heat capacity. The method described in the present invention has two advantages: First, the flight time offset is affected by the internal temperature of the battery and therefore better reflects the internal thermal state of the battery than the surface temperature of the battery, while also eliminating the need for complex sensor embedding steps in the battery; second, the battery temperature estimated by the flight time offset simplifies the battery thermal model and can be used in conjunction with common battery laboratory equipment to estimate the battery specific heat capacity, which has the advantages of low cost and no need to create a complex insulating environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1aIt is a schematic front view of the measuring device of the present invention;

[0041] Figure 1b is a schematic top view of the measuring device of the present invention;

[0042] Figure 2a It is the reference signal and other signals of ultrasonic wave;

[0043] Figure 2b is the amplitude correlation between the ultrasonic reference signal and the offset signal;

[0044] Figure 3 is a flow chart of the method of the present invention;

[0045] Figure 4 The figure shows the fitting relationship between flight time offset and temperature under different SOC;

[0046] Figure 5 The time-of-flight offset and mapped temperature for AC pulse heating and cooling processes.

[0047] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0048] 1-Ultrasonic sensor; 2-Battery; 3-Microcontroller chip; 4-Probe cable; 5-Fixed upper bracket; 6-Fixed lower bracket; 7-Couplant; 8-Bolt; 9-Nut. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0050] like Figure 1a and 1b As shown, an ultrasonic-based battery specific heat capacity measuring device includes an ultrasonic sensor 1, a microcontroller chip 3, a probe cable 4, a fixed upper bracket 5, a fixed lower bracket 6, and a coupling agent 7; a battery 2 is placed on the fixed lower bracket 6, and the coupling agent 7 is applied to a certain surface of the battery 2; then the ultrasonic sensor 1 is placed in the groove of the fixed upper bracket 5, and the fixed upper bracket 5 and the fixed lower bracket 6 are connected with bolts 8 and nuts 9 to fix the ultrasonic sensor 1 on the surface of the battery 2 coated with the coupling agent 7; the ultrasonic sensor 1 is connected to the microcontroller chip 3 through the probe cable 4.

[0051] The working mode is: the ultrasonic sensor 1 excites and receives the ultrasonic signal passing through the battery 2, and communicates the collected signal to the microcontroller chip 3, and the microcontroller chip 3 calculates and stores the flight time offset.

[0052] Specifically, the ultrasonic sensor 1 depends on the specific measurement method; for transmitted wave measurement, the ultrasonic sensor 1 includes a pair of ultrasonic pulse transmitting probes and an ultrasonic pulse receiving probe, which are respectively fixed at the same position on the opposite sides of the battery 2; for reflected wave measurement, the ultrasonic sensor 1 includes an ultrasonic pulse transmitting / receiving probe, which is fixed at any position on the surface of the battery 2; for guided wave measurement, the ultrasonic sensor 1 includes a pair of ultrasonic pulse transmitting probes and an ultrasonic pulse receiving probe, which are respectively fixed at both ends of the same surface of the battery 2.

[0053] Specifically, the excitation pulse of the microcontroller chip 3 to the ultrasonic sensor 1 is a square wave or a cosine wave, etc., and the frequency range is 0.1-5MHz; the battery 2 is a soft-pack battery or a square-shell battery.

[0054] Specifically, the method for calculating the flight time offset includes but is not limited to the cross-correlation analysis method. The cross-correlation analysis method accurately determines the flight time offset between different ultrasonic signals. Figure 2a and Figure 2b As shown, the ultrasonic signal measured earlier by battery 2 is selected as the reference signal; then, a time offset is applied to the other signals relative to the reference signal, and the amplitude correlation between the reference signal and the offset signal is calculated using the following formula:

[0055]

[0056] Where f is the reference ultrasonic signal, g is the shifted ultrasonic signal, τ is the time offset, and t is time. The offset corresponding to the maximum amplitude correlation is the flight time offset.

[0057] like Figure 3 As shown, a method for measuring the specific heat capacity of a battery based on ultrasound includes the following steps:

[0058] S1. Place the integrated battery measurement device in a temperature-controlled environment and achieve temperature balancing of the battery at several temperatures. During this time, the ultrasonic sensor activates and receives ultrasonic signals passing through the battery. The microcontroller chip calculates and stores the time-of-flight offset for each measurement and fits the relationship between the time-of-flight offset and temperature.

[0059] S101. The integrated battery measuring device is placed in a temperature-controlled environment and the battery is left standing for a sufficient period of time at any ambient temperature until the temperature is balanced;

[0060] S102. The ultrasonic sensor starts to excite and receive ultrasonic signals passing through the battery, and the microcontroller chip calculates and stores the flight time offset for each measurement;

[0061] S103. Change the ambient temperature multiple times and repeat sub-steps S101 and S102;

[0062] S104. Fit the temperature at several equilibrium moments and the corresponding flight time offsets, and the fitting formula includes but is not limited to:

[0063] ΔTOF=a1T+a0 (7)

[0064] Where ΔTOF is the time-of-flight offset, a1 and a0 are fitting coefficients, and T is the battery temperature. Formula (7) uses the ultrasonic time-of-flight offset to estimate the subsequent battery temperature when the initial battery temperature is known.

[0065] S2. Changing the state of charge (SOC) of the battery multiple times and repeating the steps described in S1 to achieve fitting of the flight time offset and temperature at multiple SOCs;

[0066] S3 applies AC pulse heating to the battery at a balanced temperature while simultaneously starting to collect the battery voltage and ultrasonic signals. If the flight time offset remains constant over a period of time, the AC pulse heating is stopped and the battery is cooled to ambient temperature.

[0067] S301. The ambient temperature is set to any temperature allowed by the measuring device, the battery is left to stand for a period of time until the temperature is balanced, and the battery voltage and ultrasonic signal are collected;

[0068] S302. Select a discharge current to discharge the battery briefly, the SOC change during the discharge process does not exceed 5%, and then select a charge current to charge the battery briefly to restore the battery to the SOC before discharge;

[0069] S303. Repeat sub-step S302 several times to achieve AC pulse heating of the battery;

[0070] S304 . If the flight time offset remains constant for a period of time, stop AC pulse heating and allow the battery to cool to ambient temperature.

[0071] S4. Map the flight time offset during the AC pulse heating-cooling phase to the battery temperature using a fitting relationship, and calculate the specific heat capacity of the battery based on the energy conservation equation.

[0072] S401. During the AC pulse heating-cooling phase, the temperature change relative to the ambient temperature is calculated as follows:

[0073]

[0074] Where ΔTOF1 is the time-of-flight offset of the ultrasonic signal relative to the temperature equilibrium, and k is the rate of change of the time-of-flight offset with temperature (for fitting formula (7), k = a1); the battery temperature is obtained by adding the temperature change to the ambient temperature;

[0075] S402. During the constant flight time offset phase of AC pulse heating, the heat generated by the battery is equal to the heat dissipated. The external heat transfer thermal resistance of the battery is calculated as follows:

[0076]

[0077] Where T0 is the battery temperature during the constant flight time offset phase, T a is the ambient temperature, is the heat generation rate during the constant flight time offset phase, which is calculated as follows:

[0078]

[0079] Where V is the battery voltage during the constant flight time offset phase, V OCV is the voltage before AC pulse heating, I is the battery current;

[0080] S403. During the battery cooling process, the rate at which the battery's internal energy decreases is equal to the external heat exchange rate. Theoretically, the formula for how the battery's temperature changes over time is:

[0081]

[0082] Where m is the mass of the battery, C p is the specific heat capacity of the battery, t is the time of the cooling process; the battery temperature during the cooling process is curve fitted according to formula (11) to obtain the specific heat capacity C p .

[0083] Follow the above steps to realize ultrasonic measurement of battery specific heat capacity, and on this basis, conduct battery thermal analysis, safety design and multi-physics simulation research.

[0084] In the embodiment of the present application, lithium manganese oxide soft-pack batteries are used as experimental objects, and reflected wave measurement is selected as the ultrasonic measurement method. An ultrasonic pulse transmitting / receiving probe is fixed at the center of the battery surface; the measuring device is placed in a constant temperature box, and the lithium-ion battery is connected to the voltage acquisition line and power supply line of the charger and discharger. Figure 4As shown in the figure, the relationship between the battery temperature of 0-50°C and the flight time offset is fitted at intervals of 25% from battery SOC=0 to SOC=100%. The fitting coefficient a1 of the flight time offset and temperature is almost unaffected by the battery SOC, so this embodiment takes the average value of a1 under different SOCs as the basis for measuring temperature, and the average value of a1 is 0.0341. This application can realize the measurement of specific heat capacity of batteries at any SOC and any temperature. Figure 5 As shown, the flight time offset of the AC pulse heating-cooling process at SOC = 50% and temperature of 25°C is mapped to temperature; compared with the specific heat capacity result of the accelerating adiabatic calorimeter, its maximum error does not exceed 6%.

[0085] In summary, the present invention proposes an ultrasonic-based device and method for measuring the specific heat capacity of a battery. An ultrasonic sensor is mounted on the surface of the battery, and the time-of-flight offset is calculated based on the collected ultrasonic signal. The relationship between the battery temperature and the time-of-flight offset is calibrated, and the specific heat capacity is calculated by applying the law of conservation of energy to the battery's AC pulse heating and cooling process. This process for calculating the specific heat capacity of a battery essentially utilizes the fact that the time-of-flight of ultrasound waves is sensitive to the internal temperature of the battery, reducing the application requirements of lumped parameter models. The method overcomes the shortcomings of traditional methods for measuring specific heat capacity and has significant practical value.

[0086] The above description is only for the preferred embodiment of the present invention and is not limited to the present invention. Any deduction, modification or replacement scheme made within the concept of the present invention is also included in the protection scope of the present invention.

Claims

1. A method for measuring the specific heat capacity of a battery based on ultrasound, using a battery specific heat capacity measuring device based on ultrasound, characterized in that: The method comprises an ultrasonic sensor (1), a microcontroller chip (3), a probe cable (4), a fixed upper bracket (5), a fixed lower bracket (6) and a coupling agent (7); the fixed upper bracket (5) and the fixed lower bracket (6) fix the ultrasonic sensor (1) on the surface of a battery (2) coated with the coupling agent (7), and the ultrasonic sensor (1) is connected to the microcontroller chip (3) via the probe cable (4); the ultrasonic sensor (1) excites and receives an ultrasonic signal passing through the battery (2), and communicates the collected signal to the microcontroller chip (3), and the microcontroller chip (3) calculates and stores a time-of-flight offset; the method is characterized in that the method comprises the following steps: S1. Placing the measuring device of the integrated battery (2) in a temperature-controlled environment to achieve temperature balancing of the battery (2) at several temperatures; during which the ultrasonic sensor (1) activates excitation and receives ultrasonic signals passing through the battery (2), and the microcontroller chip (3) calculates and stores the flight time offset of each measurement, and fits the relationship between the flight time offset and the temperature; S2. changing the state of charge (SOC) of the battery (2) multiple times and repeating the steps described in S1 to achieve fitting of the flight time offset and temperature under multiple SOCs; S3 performs AC pulse heating on the battery (2) in a temperature-balanced state, and simultaneously starts timing to collect the voltage and ultrasonic signal of the battery (2); if the flight time offset remains constant for a period of time, the AC pulse heating is stopped, and the battery (2) is cooled to ambient temperature; S4. The flight time offset of the AC pulse heating-cooling phase is mapped to the temperature of the battery (2) by the fitting relationship, and the specific heat capacity of the battery (2) is calculated according to the energy conservation equation.

2. The method for measuring battery specific heat capacity based on ultrasound according to claim 1, characterized in that: The flight time offset is calculated by cross-correlation analysis.

3. The method for measuring battery specific heat capacity based on ultrasound according to claim 1, characterized in that: The step S1 includes the following sub-steps: S101. The measuring device of the integrated battery (2) is placed in a temperature-controlled environment, and the battery (2) is left standing for a sufficient period of time at any ambient temperature until the temperature is balanced; S102. The ultrasonic sensor (1) starts to excite and receive the ultrasonic signal passing through the battery (2), and the microcontroller chip (3) calculates and stores the flight time offset of each measurement; S103. Change the ambient temperature multiple times and repeat sub-steps S101 and S102; S104. Fit the temperature at several equilibrium moments and the corresponding flight time offset. The fitting formula includes: ΔTOF=a1T+a0 (1) Wherein, ΔTOF is the flight time offset, a1 and a0 are fitting coefficients, and T is the temperature of the battery (2); Formula (1) realizes the estimation of the subsequent temperature of the battery (2) by using the flight time offset of the ultrasonic wave when the initial temperature of the battery (2) is known.

4. The method for measuring battery specific heat capacity based on ultrasound according to claim 3, characterized in that: The step S3 includes the following sub-steps: S301. The ambient temperature is set to any temperature allowed by the measuring device, the battery (2) is left to stand for a period of time until the temperature is balanced, and the battery (2) voltage and ultrasonic signal are collected; S302. Selecting a discharge current to discharge the battery (2) briefly, wherein the SOC change during the discharge process does not exceed 5%, and then selecting a charge current to charge the battery (2) briefly to restore the SOC of the battery (2) before discharge; S303. Repeat sub-step S302 several times to achieve AC pulse heating of the battery (2); S304. If the flight time offset is constant for a period of time, stop the AC pulse heating and let the battery (2) cool down to the ambient temperature.

5. The method for measuring battery specific heat capacity based on ultrasound according to claim 4, characterized in that: The step S4 includes the following sub-steps: S401. During the AC pulse heating-cooling phase, the temperature change relative to the ambient temperature is calculated as follows: Where ΔTOF1 is the flight time offset of the ultrasonic signal relative to the temperature equilibrium, k is the rate of change of the flight time offset with temperature, and for the fitting formula (1), k = a 1， The temperature change is added to the ambient temperature to obtain the battery (2) temperature; S402. In the stage where the flight time offset of the AC pulse heating is constant, the heat generation and heat dissipation of the battery (2) are equal. The calculation formula of the external heat transfer thermal resistance of the battery (2) is as follows: Where T0 is the temperature of the battery (2) during the constant flight time offset phase, T a is the ambient temperature, is the heat generation rate during the constant flight time offset phase, which is calculated as follows: Where V is the battery (2) voltage during the constant flight time offset phase, V OCV is the voltage before AC pulse heating, I is the current of battery (2); S403. During the cooling process of the battery (2), the rate of reduction of the internal energy of the battery (2) is equal to the external heat exchange rate; theoretically, the temperature change of the battery (2) over time is expressed as follows: Where, m is the mass of the battery (2), C p is the specific heat capacity of battery (2), t is the time of cooling process; the temperature of battery (2) in the cooling process is curve fitted according to formula (5) to obtain the specific heat capacity C p .

6. The method for measuring battery specific heat capacity based on ultrasound according to claim 1, characterized in that: The ultrasonic sensor depends on the specific measurement method; for transmission wave measurement, the ultrasonic sensor (1) includes a pair of ultrasonic pulse transmitting probes and ultrasonic pulse receiving probes, which are respectively fixed at the same position on the opposite sides of the battery (2); for reflection wave measurement, the ultrasonic sensor (1) includes an ultrasonic pulse transmitting / receiving probe, which is fixed at any position on the surface of the battery (2); for guided wave measurement, the ultrasonic sensor (1) includes a pair of ultrasonic pulse transmitting probes and ultrasonic pulse receiving probes, which are respectively fixed at two ends of the same surface of the battery (2).

7. The method for measuring battery specific heat capacity based on ultrasound according to claim 1, characterized in that: The excitation pulse of the microcontroller chip (3) to the ultrasonic sensor (1) is a square wave or a cosine wave, and the frequency range is 0.1-5 MHz.

Images