Flow battery charging state detection method and flow battery charging state detection system

Abstract

A method for detecting the state of charge of a redox flow battery includes: providing a redox flow battery, executing a preposition step and executing a detection step, the preposition step including providing a detection device and completely charging and discharging the redox flow battery at least once within a time interval; obtaining a waveform corresponding to a plurality of measured values and a plurality of time values in the time zone according to the signal, defining a charging state value according to the waveform, and obtaining a curve corresponding to the charging state value and the plurality of measured values; the detection step comprises the steps of detecting the negative electrode electrolyte through the detection device, outputting the signal, obtaining a numerical value according to the signal, and obtaining a charging state numerical value corresponding to the numerical value through the curve.

Description

Technical Field

[0001] The present invention relates to a liquid flow battery, and in particular to a method and a system capable of detecting the charging state of a liquid flow battery. Background Art

[0002] It is known that with the rapid development of industry, people consume fossil energy at an increasingly faster rate, which not only causes a serious shortage of fossil energy, but also makes the ecological environment worse; therefore, developing renewable energy to replace fossil energy has become an important development trend. At present, the energy storage technology of renewable energy includes redox flow battery (RFB), hereinafter referred to as flow battery, which can provide cyclic charging and discharging, and can also maintain voltage efficiently, so that renewable energy can provide stable power supply.

[0003] The existing liquid flow battery structure usually includes two battery cells and an exchange membrane, the exchange membrane is arranged between the two battery cells, each battery cell is connected to a container of a positive electrolyte and a negative electrolyte, and the containers of the positive electrolyte and the negative electrolyte are pumped to each battery cell through a pumping element for electrochemical reaction to generate electrical energy; and the current method of monitoring the charge state (SOC) of the liquid flow battery usually requires the electrolyte to be removed and diluted before detection, which not only requires the destruction of the liquid flow battery structure, but also the detection process is more complicated. Therefore, how to provide a simple and convenient liquid flow battery charge state detection method and system is an urgent problem to be solved. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method and system for detecting the charging status of a flow battery, which can monitor the charging status of the flow battery in real time without taking out the electrolyte for dilution.

[0005] In order to achieve the above-mentioned purpose, a method for detecting the charging state of a flow battery provided by the present invention includes providing a flow battery, performing a pre-step and performing a detection step, wherein the flow battery includes a negative electrode electrolyte; the pre-step includes providing a detection device, wherein the detection device includes a light source and a receiver, wherein a fixed distance is maintained between the light source and the receiver, wherein the light source emits a light of a single wavelength, wherein the light passes through the negative electrode electrolyte and is received by the receiver and outputs a signal, wherein the single wavelength is between 750 and 1100 nm; the flow battery is fully charged and discharged at least once within a time interval; a waveform corresponding to a plurality of measurement values ​​and a plurality of time values ​​within the time interval is obtained according to the signal, a state of charge (SOC) value is defined according to the waveform, and a curve corresponding to the charge state value and the plurality of measurement values ​​is obtained; the detection step includes detecting the negative electrode electrolyte by the detection device and outputting the signal, obtaining a value according to the signal, and obtaining a charge state value corresponding to the value through the curve.

[0006] The effect of the present invention is that, through the liquid flow battery charging state detection method of the present invention, the liquid flow battery charging state can be monitored in real time without taking out the electrolyte for dilution.

[0007] The present invention further provides a liquid flow battery charging state detection system for detecting the charging state (SoC) of a liquid flow battery. The liquid flow battery includes a negative electrode circulation pipeline for circulating the negative electrode electrolyte between a negative electrode and a negative electrode electrolyte storage tank. The liquid flow battery charging state detection system includes a transparent pipeline and a detection device. The transparent pipeline is connected to the negative electrode circulation pipeline; the detection device includes a light source and a receiver. The light source and the receiver are respectively arranged on opposite sides of the transparent pipeline along the radial direction. The light source emits a light of a single wavelength. After the light passes through the negative electrode electrolyte contained in the transparent pipeline, it is received by the receiver and outputs a signal.

[0008] The effect of the present invention is that, through the design of connecting the transparent pipeline with the negative electrode circulation pipeline, the negative electrode electrolyte can be directly detected without taking out the negative electrode electrolyte for detection, and the charging state of the liquid flow battery can be obtained through the signal, thereby achieving the purpose of providing a simple and convenient liquid flow battery charging state detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of a flow battery charging state detection system and a flow battery according to a preferred embodiment of the present invention.

[0010] Figure 2It is a stereoscopic diagram of the liquid flow battery charging status detection system of the above preferred embodiment.

[0011] Figure 3 It is a schematic diagram of partial component decomposition of the liquid flow battery charging status detection system of the above preferred embodiment.

[0012] Figure 4 It is a side view of the liquid flow battery charging state detection system of the above preferred embodiment, wherein the mask is indicated by an imaginary line.

[0013] Figure 5 It is a top view of the liquid flow battery charging state detection system according to the above preferred embodiment, wherein the mask is not shown.

[0014] Figure 6 This is a flow chart of a method for detecting charging status of a flow battery according to a preferred embodiment of the present invention.

[0015] Figure 7 FIG. 4 is a graph showing the changes of the sensing voltage, voltage and current over time according to the preferred embodiment of the present invention.

[0016] Figure 8 It is a curve diagram corresponding to the sensing voltage value and the charging state value according to the above preferred embodiment of the present invention.

[0017] Fig. 9 It is a curve diagram corresponding to the sensing voltage value and the charging state value with different current limiting resistor values ​​according to the above preferred embodiment of the present invention.

[0018] Description of reference numerals:

[0019] 1: Flow battery charging status detection system

[0020] 10: Transparent pipe

[0021] 20: Detection device

[0022] 22: Light Source

[0023] 24: Receiver

[0024] 30: Mask

[0025] 32: Opening

[0026] 40: base body

[0027] 50: First positioning piece

[0028] 60: Second positioning piece

[0029] A: Negative electrode

[0030] A1: Negative electrode outlet pipe

[0031] A2: Negative electrode inlet pipe

[0032] B: Flow battery

[0033] B1: Battery Cell

[0034] C: Positive electrode

[0035] L: negative electrode electrolyte

[0036] M: exchange membrane

[0037] T1: positive electrode electrolyte storage tank

[0038] T2: Negative electrolyte storage tank

[0039] X: Long axis

[0040] D: Outer diameter

[0041] S100, S200, S201, S202, S203, S300: Steps DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Figures 1 to 5 As shown, a liquid flow battery charging state detection system 1 according to a preferred embodiment of the present invention is used to detect the charging state (SoC, state of charge) of a liquid flow battery B. The liquid flow battery B includes two battery cells B1 and an exchange membrane M. The exchange membrane M is arranged between the two battery cells B1. The two battery cells B1 respectively include a positive electrode C and a negative electrode A. The two battery cells are respectively connected to a positive electrolyte storage tank T1 and a negative electrolyte storage tank T2. The positive electrolyte storage tank T1 and the negative electrolyte storage tank T2 are respectively pumped to each battery cell B1 through a pumping element for electrochemical reaction to generate electrical energy.

[0043] The liquid flow battery B also includes a positive electrode circulation pipeline and a negative electrode circulation pipeline. The positive electrode circulation pipeline is used to circulate the positive electrode electrolyte between the positive electrode C and the positive electrode electrolyte storage tank T1, and the negative electrode circulation pipeline is used to circulate the negative electrode electrolyte between the negative electrode A and the negative electrode electrolyte storage tank T2.

[0044] Please cooperate Figure 3The liquid flow battery charging state detection system 1 includes a transparent pipeline 10 and a detection device 20, wherein the transparent pipeline 10 is connected to the negative electrode circulation pipeline. For example, the negative electrode circulation pipeline includes a negative electrode outlet pipeline A1 and a negative electrode inlet pipeline A2, the negative electrode outlet pipeline A1 is used to output the negative electrode electrolyte at the negative electrode A to the negative electrode electrolyte storage tank T2, and the negative electrode inlet pipeline A2 is used to input the negative electrode electrolyte in the negative electrode electrolyte storage tank T2 to the negative electrode A; in this embodiment, the transparent pipeline 10 and the detection device 20 are arranged at the negative electrode outlet pipeline A1, wherein the transparent pipeline 10 is connected to the negative electrode outlet pipeline A1, so that the negative electrode electrolyte output from the negative electrode A to the negative electrode electrolyte storage tank T2 can pass through the transparent pipeline 10.

[0045] In other embodiments, it is not excluded that the transparent pipe 10 and the detection device 20 are disposed at the negative electrode inlet pipe A2, and the transparent pipe 10 is connected to the negative electrode inlet pipe A2.

[0046] It is further explained that the transparent pipe 10 is a glass tube, and the outer diameter D of the transparent pipe is between 5.4 and 6.6 mm. Preferably, the outer diameter D of the transparent pipe is 6 mm. In practice, it is not excluded that the transparent pipe 10 is made of any transparent material. For example, the transparent pipe can be made of any transparent material that does not absorb wavelengths of 750 to 1100 nm. In addition, it is not excluded that the outer diameter D of the transparent pipe is an outer diameter of other sizes.

[0047] Please cooperate Figure 5 The detection device 20 includes a light source 22 and a receiver 24. The light source 22 and the receiver 24 are radially arranged on opposite sides of the transparent tube 10, and the opposite sides of the transparent tube 10 are in contact with the light source 22 and the receiver 24 respectively. The light source 22 emits a light of a single wavelength. After passing through the transparent tube 10 and the negative electrode electrolyte contained in the transparent tube 10, the light is received by the receiver 24 and outputs a signal. Therefore, the charging state of the liquid flow battery B can be obtained through the signal.

[0048] In this embodiment, the example in which both the light source 22 and the receiver 24 are arranged outside the transparent pipe 10 is used for explanation; in practice, at least one of the light source 22 and the receiver 24 may be arranged inside the transparent pipe 10. For example, the light source 22 may be arranged outside the transparent pipe 10 and the receiver 24 may be arranged inside the transparent pipe 10, or the receiver 24 may be arranged outside the transparent pipe 10 and the light source 22 may be arranged inside the transparent pipe 10, or both the light source 22 and the receiver 24 may be arranged inside the transparent pipe 10; preferably, the receiver 24 arranged inside the transparent pipe 10 is covered and arranged in a transparent waterproof material, so that the light of the light source 22 can pass through the transparent waterproof material to be received by the receiver 24, and the negative electrode electrolyte in the transparent pipe 10 can be prevented from directly contacting the receiver 24 and being damaged.

[0049] The detection device 20 is a transmittance sensor including the light source 22 and the receiver 24. The signal output by the transmittance sensor is a voltage signal. The light source 22 can be an LED light source or a laser light source, and the single wavelength is between 750 and 1100 nm. Preferably, the single wavelength is 850 nm. It is further explained that the detection device 20 includes a current limiting resistor electrically connected to the light source 22. Therefore, the user can adjust the size of the current limiting resistor to adjust the light intensity emitted by the light source 22.

[0050] It is further explained that if Figures 3 to 5 As shown, the flow battery charging state detection system 1 includes a mask 30, a base 40, two first positioning members 50 and two second positioning members 60. The light source 22 and the receiver 24 are disposed on the top of the base 40, the mask 30 is made of an opaque material, disposed on the top of the base 40 and together with the top of the base 40, forms a receiving space, a portion of the transparent pipe 10 is received in the receiving space, and the mask 30 is detachably connected to the top of the base 40.

[0051] The mask 30 has an opening 32 on two opposite sides, and the transparent pipe 10 is passed through the openings 32 on both sides of the mask 30. Therefore, both ends of the transparent pipe 10 can pass through the mask 30 to communicate with the negative electrode outlet pipe A1. In addition, through the setting of the mask 30, it is possible to effectively isolate the light from the external space from entering the accommodating space to interfere with the detection result of the detection device 20, thereby achieving the effect of improving the detection accuracy of the detection device 20.

[0052] Please cooperate Figure 4, defining a long axis X, the transparent pipe 10 extends along the long axis X, the two first positioning members 50 are arranged on the top of the base 40, in the direction of the long axis X, the light source 22 and the receiver 24 are arranged between the two first positioning members 50, and the transparent pipe 10 is arranged on the top of the two first positioning members 50; in the direction of the long axis X, the two second positioning members 60 are arranged between the two first positioning members 50, the two second positioning members 60 are connected to the mask 30 and the bottoms of the two second positioning members 60 are against the outer wall of the transparent pipe 10, through the arrangement of the two first positioning members 50 and the two second positioning members 60, the transparent pipe 10 can be stably arranged on the base 40.

[0053] Please refer to Figure 6 As shown, it is a flow chart of a liquid flow battery charging state detection method according to a preferred embodiment of the present invention. In this embodiment, the liquid flow battery charging state detection method is executed by using the above-mentioned liquid flow battery charging state detection system 1 as an example. In other embodiments, it is not excluded that the liquid flow battery charging state detection method is executed by other devices.

[0054] The method for detecting the charging state of a flow battery comprises the following steps:

[0055] Step S100, providing the liquid flow battery B, wherein the liquid flow battery B comprises the negative electrode electrolyte L;

[0056] Step S200, executing a pre-step, the pre-step comprising:

[0057] Step S201, providing the detection device 20, the detection device 20 includes a light source 22 and a receiver 24, the light source 22 and the receiver 24 maintain a fixed distance, the fixed distance is preferably 6mm, the light source 22 emits a single wavelength of light, the light passes through the negative electrode electrolyte L and is received by the receiver 24 and outputs a signal, the signal is a sensing voltage, wherein the signal is illustrated by an analog signal as an example, in other embodiments, the signal can be an analog signal or a digital signal converted from analog to digital, the single wavelength is between 750 and 1100nm, preferably, the single wavelength is 850nm; as above The liquid flow battery B includes the negative electrode outlet pipe A1 to output the negative electrode electrolyte L from the negative electrode A to the negative electrode storage tank T2, and the detection device 20 detects the negative electrode electrolyte L in the negative electrode outlet pipe A1; it is further explained that in this embodiment, the light source 22 and the receiver 24 of the detection device 20 are arranged at the negative electrode outlet pipe to detect the negative electrode electrolyte in the transparent pipe 10, and in other embodiments, the light source 22 and the receiver 24 of the detection device 20 can also be arranged in the negative electrode electrolyte storage tank T2 or the negative electrode inlet pipe A2 to detect the negative electrode electrolyte.

[0058] Step S202, the flow battery B is fully charged and discharged at least once within a time interval; preferably, a pre-charge and discharge is performed before the at least one full charge and discharge, wherein the at least one full charge and discharge includes charging in a constant current mode and charging-discharging in a constant voltage mode, and the current density is 40 mA / cm 2 In this embodiment, if Figure 7 As shown in FIG. 1 , it is a graph showing the changes of the sensing voltage, voltage and current over time after the electrolyte is fully charged and discharged for the first time. It should be noted that in other embodiments, considering the conversion efficiency of the battery system, it is not excluded that a voltage higher than 40 mA / cm 2 Lower or higher current density charge and discharge cycle testing.

[0059] Step S203, obtaining a waveform corresponding to a plurality of measurement values ​​and a plurality of time values ​​in the time zone according to the signal, that is, a waveform corresponding to a plurality of voltage values ​​and a plurality of time values, and defining a charge state (SoC) value according to the waveform (coordinated with Figure 7 ), and obtain a curve corresponding to the plurality of measured values ​​and the charging state values ​​(matching Figure 8 ), the multiple measurement values ​​are the sensing voltage values ​​output by the receiver 24.

[0060] The pre-step includes adjusting the intensity of the light source 22 so that the slope of any segment of the curve is not equal to 0 and is not infinite; and by adjusting the size of the current limiting resistor, the intensity of the light emitted by the light source 22 can be adjusted, such as Fig. 9 As shown, with different current limiting resistance values ​​of 0, 100, 200 ..., 900Ω, multiple curves corresponding to the sensing voltage and the charging state value can be obtained. When the current limiting resistance value is 0, 100, 200 or 300Ω, it can be seen that when the SoC is greater than 60%, the slope of the curve is zero, and there will be a problem that the charging state change cannot be judged; when the current limiting resistance value is 600, 700, 800 or 900Ω, the slope of the curve changes less, and there will be a problem that the resolution is small and it is not easy to judge the charging state change; in this embodiment, Fig. 9 As shown, when the current limiting resistance value is 400 or 500Ω, the slope of the curve changes greatly, and a better resolution for distinguishing the change of the charging state can be obtained.

[0061] Step S300, executing a detection step, including detecting the negative electrode electrolyte through the detection device 20 and outputting the signal, obtaining a value according to the signal, and obtaining a charging state value corresponding to the value through the curve; that is, the user can obtain a sensing voltage value through the signal, and then compare it with the curve graph corresponding to the sensing voltage and the charging state value obtained after executing steps S100 and S200 to obtain the corresponding charging state value.

[0062] In summary, the effect of the present invention is that it can directly detect the negative electrode electrolyte, and the charging state of the flow battery can be obtained through the signal, thereby achieving the purpose of providing a simple and convenient flow battery charging state detection system.

[0063] The above description is only a preferred feasible embodiment of the present invention. Any equivalent changes made by applying the description and claims of the present invention should be included in the patent scope of the present invention.

Claims

1. A method for detecting the charging state of a flow battery, comprising: A liquid flow battery is provided, comprising a negative electrolyte; Perform a pre-step, including: A detection device is provided, the detection device comprising a light source and a receiver, the light source and the receiver are kept at a fixed distance, the light source emits a light of a single wavelength, the light passes through the negative electrode electrolyte and is received by the receiver and outputs a signal, the single wavelength is between 750nm and 1100nm; Fully charging and discharging the liquid flow battery at least once within a time interval; Obtaining a waveform corresponding to a plurality of measurement values ​​and a plurality of time values ​​in the time zone according to the signal, defining a charging state value according to the waveform, and obtaining a curve corresponding to the charging state value and the plurality of measurement values; and Perform a detection step, including: The negative electrode electrolyte is detected by the detection device and the signal is outputted. A value is obtained according to the signal, and a charging state value corresponding to the value is obtained through the curve.

2. The method for detecting the charging state of a flow battery as claimed in claim 1, wherein the preceding step comprises adjusting the intensity of the light source so that the slope of any segment of the curve is not equal to 0 and is not infinite.

3. The method for detecting the charging state of a flow battery as claimed in claim 1, wherein the single wavelength is 850 nm. 4 . The method for detecting the charging status of a flow battery as claimed in claim 1 , wherein the detection device is a transmittance sensor comprising the light source and the receiver.

5. The method for detecting the charging state of a flow battery as claimed in claim 1, wherein the pre-step comprises performing a pre-charge and discharge before the at least one full charge and discharge. 6 . The method for detecting the charge state of a flow battery according to claim 1 , wherein the at least one complete charge-discharge comprises charging in a constant current mode and charging-discharging in a constant voltage mode.

7. A method for detecting the charging status of a liquid flow battery as described in claim 1, wherein the liquid flow battery comprises a negative electrode outlet pipeline to output negative electrode electrolyte from a negative electrode to a negative electrode electrolyte storage tank, and the detection device detects the negative electrode electrolyte in the negative electrode outlet pipeline.

8. The method for detecting the charging status of a flow battery as claimed in claim 1, wherein the negative electrode electrolyte is contained in a transparent pipe, and the light source and the receiver are disposed outside the transparent pipe.

9. The method for detecting the charging status of a flow battery as claimed in claim 7, wherein the negative electrode electrolyte is contained in a transparent pipe, and at least one of the light source and the receiver is disposed inside the transparent pipe. 10 . The method for detecting the charging state of a flow battery according to claim 9 , wherein the receiver is disposed inside the transparent pipe.

11. The method for detecting the charging status of a flow battery as claimed in claim 10, wherein the receiver is coated in a transparent waterproof material.

12. A liquid flow battery charging state detection system for detecting the charging state of a liquid flow battery, wherein the liquid flow battery comprises a negative electrode circulation pipeline for circulating negative electrode electrolyte between a negative electrode and a negative electrode electrolyte storage tank, comprising: a transparent pipeline connected to the negative electrode circulation pipeline; and A detection device includes a light source and a receiver. The light source and the receiver are respectively arranged on opposite sides along the radial direction of the transparent tube. The light source emits a light with a single wavelength. After the light passes through the negative electrode electrolyte contained in the transparent tube, it is received by the receiver and outputs a signal. 13 . The liquid flow battery charging status detection system as claimed in claim 12 , wherein the outer diameter of the transparent tube is between 5.4 mm and 6.6 mm.

14. The liquid flow battery charging state detection system according to claim 13, wherein the outer diameter of the transparent tube is 6 mm.

15. The flow battery charging state detection system as claimed in claim 12, wherein the single wavelength is between 750 nm and 1100 nm.

16. The flow battery charge state detection system of claim 15, wherein the single wavelength is 850 nm.

17. The liquid flow battery charging status detection system as claimed in claim 12, wherein the detection device comprises a current limiting resistor electrically connected to the light source. 18 . The liquid flow battery charging status detection system as claimed in claim 12 , wherein the transparent pipe is a glass pipe or a pipe made of any transparent material that does not absorb wavelengths of 750 nm to 1100 nm.

19. The liquid flow battery charging state detection system as claimed in claim 12, comprising a mask, wherein the mask has an opening on two opposite sides respectively, and the transparent pipe is disposed through the openings on the two sides of the mask.

20. The liquid flow battery charging status detection system as described in claim 19 comprises a base, the light source and the receiver are arranged on the top of the base, the cover is arranged on the top of the base and forms a containing space together with the top of the base, and part of the transparent pipe is accommodated in the containing space.

21. The liquid flow battery charging status detection system as described in claim 20 comprises two first positioning members and two second positioning members, defining a long axis, the transparent pipe extending along the long axis, the two first positioning members are arranged on the top of the base body, and in the direction of the long axis, the light source and the receiver are arranged between the two first positioning members, and the transparent pipe is arranged on the top of the two first positioning members; in the direction of the long axis, the two second positioning members are arranged between the two first positioning members, the two second positioning members are connected to the mask and the bottoms of the two second positioning members are against the outer wall of the transparent pipe.

22. The liquid flow battery charging state detection system as claimed in claim 12, wherein the light source and the receiver are disposed outside the transparent pipe.

23. The flow battery charging state detection system of claim 12, wherein at least one of the light source and the receiver is disposed inside the transparent tube.

24. The liquid flow battery charging state detection system according to claim 12, wherein the receiver is disposed inside the transparent pipe.

25. The flow battery charging status detection system as claimed in claim 24, wherein the receiver is coated in a transparent waterproof material.

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