Battery energy storage sensing device and system

Abstract

The utility model relates to a battery energy storage sensing device and system, and the device comprises an impedance analysis unit which provides an AC signal to a battery, and carries out the analysis of the electrochemical impedance spectrum of the battery, so as to provide the impedance of the battery; the sensing unit is used for sensing the voltage and the current of the battery in the discharging process of the battery so as to generate a voltage time record and a current time record; the calculation unit is used for providing the maximum storable electric quantity of the battery according to the impedance, the voltage time record, the current time record and a closed solution electrochemical equation, and the calculation unit is used for providing the maximum storable electric quantity of the battery according to the impedance, the voltage time record, the current time record and the closed solution electrochemical equation; or the calculation unit provides the maximum storable electric quantity of the battery according to the voltage time record, the current time record, a reaction rate coefficient and a voltage change rate equation.

Description

Technical Field

[0001] The present application relates to a battery energy storage sensing device and system, and more particularly to a battery energy storage sensing device and system that can determine the maximum amount of electricity that can be stored in real time without requiring full discharge. Background Art

[0002] In the prior art, the maximum amount of electricity that a battery can store, also known as the "maximum amount of electrochemically active ions inside the battery," is an important indicator of battery performance and life. Traditionally, a general battery energy storage sensing system determines the amount of electricity that can be stored by measuring or judging the maximum amount of electricity that can be stored based on the amount of electricity released during the full discharge of the battery. However, in actual operation, the full discharge process of most batteries takes too long, and it may be impossible or inconvenient to operate to full discharge. In addition, the full discharge process can easily damage the battery and has a great impact on the life of the battery itself; and the maximum amount of electricity that can be stored measured by each full discharge is different, that is, the maximum amount of electricity that can be stored generated or measured in the previous full discharge is different from the maximum amount of electricity that can be stored measured after the next full discharge.

[0003] Other traditional ways of measuring the amount of electricity that can be stored, such as rapid discharge in a short period of time, are used to measure the maximum amount of electricity that can be stored. However, rapid discharge is more likely to cause serious damage to the battery itself. In addition, the noise during rapid discharge is very high, and the current during discharge is very large. The proportion of heat energy converted into heat due to the Joule effect is very high, so the sensing value of the maximum amount of electricity that can be stored is low, resulting in distorted and extremely inaccurate measurement results.

[0004] In summary, whether it is the traditional method of measuring the maximum amount of electricity that can be stored by full discharge or the traditional method of measuring the maximum amount of electricity that can be stored by rapid discharge, there are many shortcomings that cause serious damage to the battery. In view of this, in the battery management system, it is necessary to propose a battery energy storage sensing device or system that can accurately determine and measure the maximum amount of electricity that can be stored without full discharge or rapid discharge, and has real-time monitoring and sensing capabilities. This is a major issue that is extremely needed in the market, but difficult to achieve and solve. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present application is to provide a battery energy storage sensing device and system, which is a battery energy storage sensing system that determines and measures the maximum amount of electricity that can be stored in the battery according to the battery voltage, discharge current and discharge time during the battery discharge process.

[0006] The purpose of the present application and the technical problem to be solved are achieved by adopting the following technical solutions. In one aspect, according to the present application, a battery energy storage sensing device is proposed, which is used in a battery management system to monitor the capacity in real time and accurately determine the maximum amount of electricity that can be stored. The battery energy storage sensing device includes: an impedance analysis unit, which provides AC power to a battery to perform electrochemical impedance spectroscopy (EIS) analysis of the battery to determine the impedance of the battery; a sensing unit, which senses the voltage and current of the battery during a discharge process of the battery to generate a voltage time record and a current time record; and a calculation unit, which determines and provides the maximum amount of electricity that can be stored in the battery based on the impedance, voltage time record, current time record and a closed solution electrochemical equation; or the calculation unit determines and provides the maximum amount of electricity that can be stored in the battery based on the voltage time record, current time record, reaction rate coefficient and voltage change rate equation. Among them, the maximum amount of electricity that can be stored is related to the impedance, voltage time record, current time record and a closed solution electrochemical equation; or it is related to the voltage time record, current time record, reaction rate coefficient and voltage change rate equation.

[0007] In one embodiment, the voltage change rate equation is a relationship between the maximum storable power of the battery, the voltage change rate, the current time record, and the reaction rate coefficient of the battery.

[0008] In one embodiment, the battery impedance includes: the electrode resistance of the battery, the resistance from the electrode to the electrolyte, and the Warburg impedance.

[0009] In one embodiment, the AC signal is a single-frequency signal, a multi-frequency combination signal, or a square wave signal.

[0010] In one embodiment, the reaction rate coefficient of the cell is the rate coefficient of the reaction efficiency at the interface between the electrode and the electrolyte in the battery.

[0011] In one embodiment, the discharge process of the battery is a discharge with a variable current value.

[0012] With regard to another aspect, the present application provides a battery energy storage sensing system for use in a battery management system, comprising: an impedance analysis unit, which provides an alternating current to a battery to perform an electrochemical impedance spectroscopy analysis of the battery to determine the battery impedance; a charge and discharge unit, which is used to charge and discharge the battery; a sensing unit, which senses the voltage time record and current time record of the battery during the discharge process of the battery; and a calculation unit, which substitutes the impedance, voltage time record, and current time record into a closed solution electrochemical equation through a fine-tuning program to obtain and provide a maximum storable amount of electricity of the battery.

[0013] In one embodiment, the fine-tuning procedure includes an engineering calibration or a parameter solving procedure, and the parameter solving procedure includes curve fitting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of a battery energy storage sensing system according to an embodiment of the present application is shown.

[0015] Figure 2 A schematic diagram showing the relationship between impedance and alternating current frequency in electrochemical impedance spectroscopy analysis of a battery according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0016] The other technical contents, features and effects mentioned above in this application will be clearly presented in the detailed description of the preferred embodiments with reference to the drawings below. The description of the following embodiments is with reference to the attached drawings to illustrate specific embodiments that can be implemented in this application. The other technical contents, features and effects mentioned above in this application will be clearly presented in the detailed description of the preferred embodiments with reference to the drawings below.

[0017] The accompanying drawings and descriptions are considered to be illustrative in nature and not restrictive. In the drawings, units with similar structures are represented by the same reference numerals. In addition, for the sake of understanding and ease of description, the size and thickness of each component shown in the drawings are arbitrarily shown, but the application is not limited thereto.

[0018] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, characteristics and effects of a battery energy storage sensing device, system and method proposed in the present application in combination with the accompanying drawings and preferred embodiments.

[0019] Please refer to Figure 1, the present application provides a schematic diagram of a battery energy storage sensing system 100 . The battery energy storage sensing system 100 used in a battery management system includes: an impedance analysis unit 12, which provides an alternating current to a battery Bat to perform electrochemical impedance spectroscopy analysis of the battery Bat to determine the impedance Imp of the battery Bat; a charge and discharge unit 14, which is used to charge and discharge the battery Bat; a sensing unit 16, which senses the voltage and current of the battery Bat during the discharge process of the battery Bat to generate a voltage time record Infv and a current time record Infc; and a calculation unit 18, which calculates and provides a maximum storable power Qrm (Real-time maximal energy storage capacity) of the battery Bat, wherein the calculation unit 18 determines the maximum storable power Qrm of the battery Bat according to the impedance, the voltage time record Infv, the current time record Infc and a closed solution electrochemical equation Fc; or the calculation unit 18 determines the maximum storable power Qrm of the battery Bat according to the voltage time record Infv, the current time record Infc, a reaction rate coefficient k and a voltage change rate equation Fv. That is, the maximum amount of electricity that can be stored is related to impedance, voltage time record, current time record and a closed solution electrochemical equation; or it is related to voltage time record, current time record, a reaction rate coefficient and a voltage change rate equation. The operation sequence of the closed solution electrochemical equation Fc and the voltage change rate equation Fv in the figure only shows the design of one embodiment. This method mainly calculates the known parameter values ​​in the voltage change rate equation Fv first, then enters the closed solution electrochemical equation Fc to calculate the corresponding preliminary maximum amount of electricity that can be stored, and finds the reaction rate coefficient k to complete the calculation of the voltage change rate equation Fv. And the maximum amount of electricity that can be stored Qrm is determined from the preliminary maximum amount of electricity that can be stored generated by the closed solution electrochemical equation Fc and the voltage change rate equation Fv.

[0020] In one embodiment, the closed solution electrochemical equation Fc and the voltage change rate equation Fv are calculated in parallel, and the calculation unit 18 determines which of the initial maximum storable electricity generated by the closed solution electrochemical equation Fc and the voltage change rate equation Fv is the maximum storable electricity Qrm. Among them, the reaction rate coefficient k in the voltage change rate equation Fv can be a stored reaction rate coefficient k, and its details are described in the subsequent embodiments.

[0021] In one embodiment, the closed electrochemical equation Fc is the maximum storable charge Qrm of the battery Bat, the impedance Imp, the voltage time record Infv, the current time record Infc and a closed electrochemical equation: Qrm = Fc (Imp, k, I). The aforementioned reaction rate coefficient k can be generated through the calculation process of the closed electrochemical equation.

[0022] In one embodiment, the voltage change rate equation Fv is a relationship between the maximum storable power Qrm of the battery Bat, the voltage change rate Vcr, the discharge current I in the current time record Infc (or the discharge current I sensed by the sensing unit 16), and the reaction rate coefficient k of the battery Bat: Qrm=Fv(Vcr,k,I).

[0023] In another aspect, the present invention provides a battery energy storage sensing system 100, comprising: an impedance analysis unit 12, providing an alternating current AC to a battery Bat, performing electrochemical impedance spectroscopy analysis of the battery Bat to determine the battery impedance; a charge and discharge unit 14, used to charge and discharge the battery; a sensing unit 16, sensing the voltage time record Infv and the current time record Infc of the battery Bat during the discharge process of the battery Bat; and a calculation unit 18, determining a first preliminary maximum storable capacity of the battery Bat according to the voltage time record Infv, the current time record Infc, the reaction rate coefficient k and a voltage change rate equation Fv; the calculation unit 18 calculates a second preliminary maximum storable capacity of the battery Bat according to the impedance, the voltage time record Infv, the current time record Infc and a closed solution electrochemical equation Fc. The calculation unit 18 can select the first preliminary maximum storable capacity or the second preliminary maximum storable capacity as the maximum storable capacity Qrm according to different operating conditions. For example, the first preliminary storable power usage time can be applied to the situation where the reaction rate coefficient k is known, there is no impedance information of the battery Bat, and the maximum storable power Qrm needs to be temporarily determined. When the sensing time is long, the calculation unit 18 can choose to use the second preliminary storable maximum power as the maximum storable power Qrm of the battery Bat. In this way, the present invention can decide which method to use to determine the maximum storable power Qrm according to different needs.

[0024] Regarding the main difference between the two calculation methods, in one embodiment, the second preliminary maximum storable electricity according to the closed solution electrochemical equation Fc is the maximum storable electricity Qrm generated according to the current time record Infc of continuous discharge for a period of time. In addition, the first preliminary maximum storable electricity according to the voltage change rate equation Fv is the maximum storable electricity Qrm generated in real time according to the current time record Infc and the voltage change rate of real-time discharge. Both of the above-mentioned methods do not require complete discharge to calculate the maximum storable electricity Qrm. In addition, the calculation conditions of the two methods are also different. If necessary, they can also be combined together, for example, the reaction rate coefficient k used in the voltage change rate equation Fv can be generated according to the closed solution electrochemical equation Fc. According to this explanation, the calculation of the voltage change rate equation Fv and the closed solution electrochemical equation Fc in the calculation unit 18 can also be processed independently, for example, according to the use condition, a calculation method of one of the two equations is used alone, so that the calculation flexibility of the maximum storable electricity Qrm can be provided.

[0025] In one embodiment, the reaction rate coefficient k of the battery Bat is the rate coefficient of the reaction efficiency at the interface between the electrode and the electrolyte in the battery Bat. In addition to determining the maximum amount of electricity that can be stored Qrm, the reaction rate coefficient k can also be used to determine the health status of the battery Bat. Because the reaction rate coefficient k of the battery Bat is limited during the discharge process. After the closed solution of the electrochemical equation Fc generates the reaction rate coefficient k, this reaction rate coefficient k can be used in the calculation of the voltage change rate equation Fv during multiple consecutive discharges. After multiple discharge calculations, the reaction rate coefficient k is regenerated to maintain the accuracy of the calculation.

[0026] Reference Figure 1 , 2 In one embodiment, the impedance analysis unit 12 can be input to the battery Bat according to the alternating current AC of different frequencies. This electrochemical impedance spectrum analysis can be generated by the alternating current AC of different frequencies to determine the impedance Imp of the battery Bat. Among them, Warburg impedance can be used to determine the electrical performance of the battery Bat through diffusion. In one embodiment, the impedance Imp of the battery Bat is determined by gradually increasing the frequency of the alternating current AC. The impedance Imp of the battery Bat includes: the electrode resistance Re of the battery Bat, the resistance Rct from the electrode to the electrolyte, and the Warburg diffusion impedance. These impedances can be generated by electrochemical impedance spectrum analysis. Figure 2 The impedance analysis is only a schematic diagram and may vary depending on the characteristics of the battery, such as Figure 2There is only one semicircular arc curve in the figure, while other examples may have two or even three semicircular arc curves, which all fall within the scope of application of the present invention. The impedance analysis in various curve types is a known technology and will not be described in detail here.

[0027] In one embodiment, the alternating current AC is a single frequency signal (e.g., a frequency for sensing a specific impedance), a multi-frequency combination signal (e.g., an alternating current combining two or more frequencies at the same time), or a square wave signal (according to Fourier transform, a square wave signal can be an alternating current combining multiple frequencies). In the present invention, by adjusting the frequency of the alternating current AC, a frequency sweep is performed in the frequency domain to determine the impedance Imp of the battery Bat, and the impedances of the battery Bat can be quickly known by this frequency sweep.

[0028] In one embodiment, the discharge process of the battery Bat is a discharge with a variable current value. The present invention is not limited to the sensing of the maximum storable power Qrm during the discharge process with a fixed current, but can also be used for the sensing of the maximum storable power Qrm during the discharge process with a variable current. This technical feature can satisfy the requirement that the maximum storable power Qrm can still be sensed when different currents may appear during the discharge of the battery Bat due to different operating conditions.

[0029] In one embodiment, the maximum amount of electricity Qrm that can be stored can be used to determine the electrical performance of the battery Bat, such as the state of health (SOH), state of charge (SOC), or end of life of the battery.

[0030] According to the above, the present application has a flexibility, and can still sense the maximum storable power Qrm of the battery Bat during various discharge operations.

[0031] Reference Figure 1 In another aspect, the present invention provides a battery energy storage sensing system 100 for use in a battery management system, comprising: an impedance analysis unit 12, providing an alternating current to a battery Bat, performing electrochemical impedance spectroscopy analysis of the battery Bat to determine the battery impedance; a charge and discharge unit 14, used to charge and discharge the battery Bat; a sensing unit 16, sensing the voltage time record Infv and the current time record Infc of the battery Bat during the discharge process of the battery Bat; and a calculation unit 18, substituting the impedance, the voltage time record Infv, and the current time record Infc into a closed solution electrochemical equation Fc through a fine-tuning program to calculate a maximum storable amount of electricity Qrm of the battery Bat.

[0032] In one embodiment, the fine-tuning procedure includes an engineering correction or parameter solving procedure, and curve fitting is only one method in the parameter solving procedure. The parameter solving procedure may also include many methods, such as ignoring the values ​​with large deviations, judging the statistical regression effect of the values, etc., to judge the appropriate battery parameter value.

[0033] The phrase "in one embodiment" is used repeatedly in this application. This phrase does not usually refer to the same embodiment; however, it can also refer to the same embodiment. The words "comprising", "having" and "including" are synonymous unless the context indicates otherwise.

[0034] The above description is only a specific embodiment of the present application, which is intended to make it easier for those familiar with the present technology to understand the content of the present invention, and does not limit the present application in any form. Although the present application has been disclosed as above with specific embodiments, it is not used to limit the present application. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments with equivalent changes without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A battery energy storage sensing device, used in a battery management system, characterized in that: The battery energy storage sensing device comprises: an impedance analysis unit, providing an alternating current to a battery to perform electrochemical impedance spectroscopy analysis of the battery to determine the impedance of the battery; a sensing unit, for sensing a voltage time record and a current time record of the battery during a discharge process of the battery; as well as A calculation unit provides a maximum storable amount of electricity of the battery based on the battery impedance, the voltage-time record, the current-time record and a closed-form electrochemical equation; or provides the maximum storable amount of electricity of the battery based on the voltage-time record, the current-time record, a reaction rate coefficient and a voltage change rate equation.

2. The battery energy storage sensing device according to claim 1, characterized in that: The voltage change rate equation is a relationship between the voltage change rate of the battery, the current time record, the reaction rate coefficient, and the maximum storable power.

3. The battery energy storage sensing device according to claim 1, characterized in that: The battery impedance includes: the electrode resistance of the battery, the resistance from the electrode to the electrolyte, and the Warburg diffusion impedance.

4. The battery energy storage sensing device according to claim 1, characterized in that: The impedance analysis unit determines the battery impedance according to the AC power of different frequencies input into the battery.

5. The battery energy storage sensing device according to claim 1, characterized in that: The AC signal is a single-frequency signal, a multi-frequency combination signal, or a square wave signal.

6. The battery energy storage sensing device according to claim 1, characterized in that: The reaction rate coefficient of the battery is the rate coefficient of the reaction efficiency at the interface between the electrode and the electrolyte in the battery.

7. The battery energy storage sensing device according to claim 1, characterized in that: The discharging process of the battery is a discharge with a variable current value.

8. A battery energy storage sensing system, used in a battery management system, characterized in that: The battery energy storage sensing system comprises: An impedance analysis unit provides an alternating current to a battery to perform electrochemical impedance spectroscopy analysis of the battery to determine the battery impedance: a sensing unit, which senses a voltage time record and a current time record of the battery during a discharge process of the battery; as well as A calculation unit provides a maximum storable power of the battery according to the battery impedance, the voltage time record, the current time record and a fine-tuning procedure.

9. The battery energy storage sensing system according to claim 8, characterized in that: The fine-tuning procedure includes engineering correction or parameter solving procedure, which in turn includes curve fitting.

10. The battery energy storage sensing system according to claim 8, characterized in that: The calculation unit provides the maximum storable amount of electricity of the battery based on the battery impedance, the voltage time record, the current time record, the fine-tuning procedure and a closed solution electrochemical equation; or, the calculation unit provides the maximum storable amount of electricity of the battery based on the voltage time record, the current time record, a reaction rate coefficient and a voltage change rate equation, and the fine-tuning procedure.

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