Measuring device and using method thereof

Abstract

The invention relates to the technical field of batteries, and discloses a measuring device and a use method of the measuring device, the measuring device comprises a transparent tube, a liquid injection tube and a valve assembly; the transparent tube is provided with a first connecting end and a second connecting end, and the first connecting end and the second connecting end are respectively used for connecting a battery, are arranged at an interval in the height direction and are communicated with the accommodating cavity; the liquid injection pipe is connected and communicated with the transparent pipe; the valve assembly is arranged on the liquid injection pipe and used for opening and closing the liquid injection pipe. Wherein the outer wall surface of the transparent tube is provided with scales, the scales are used for marking the liquid level height of the electrolyte in the transparent tube, the electrolyte injection tube is used for injecting the electrolyte into the transparent tube, the measurement device is used for measuring the extrusion amount and the back-suction amount of the electrolyte in the battery cell in the charging and discharging process of the battery, the error of the measurement result is relatively small, and the measurement precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a measuring device and a method for using the measuring device. Background Art

[0002] Currently, during the charging and discharging process of a lithium-ion battery, the battery cell undergoes a reversible breathing behavior of expansion and contraction. At this time, the electrolyte inside the battery cell experiences a process of extrusion and re-suction. If the extrusion amount and re-suction amount of the electrolyte do not match, it is easy to cause a lack of liquid inside the battery cell, thereby affecting the battery capacity. In related technologies, since the battery is a sealed structure and the internal electrolyte distribution state cannot be directly observed with the naked eye, usually, the change amount of the electrolyte inside the battery cell is measured by destructive behaviors such as disassembling the battery to collect the free electrolyte. However, since the electrolyte is extremely volatile, the measurement error of this measurement method is extremely large, which is not conducive to evaluating the performance of the battery. Summary of the Invention

[0003] The primary object of the present invention is to provide a measuring device that measures the extrusion amount and re-suction amount of the electrolyte inside the battery cell during the charging and discharging process of the battery, thereby improving the measurement accuracy.

[0004] To achieve the above object, the present invention provides a measuring device for measuring the electrolyte content in the accommodation cavity of a battery. The battery has a height direction. The measuring device includes a transparent tube, a liquid injection tube, and a valve assembly.

[0005] The transparent tube has a first connection end and a second connection end. The first connection end and the second connection end are respectively used to connect the battery and are spaced apart in the height direction, and are communicated with the accommodation cavity.

[0006] The liquid injection tube is connected to and communicated with the transparent tube.

[0007] The valve assembly is arranged on the liquid injection tube, and the valve assembly is used to open and close the liquid injection tube.

[0008] Wherein, the outer wall surface of the transparent tube has scales, and the scales are used to mark the liquid level height of the electrolyte in the transparent tube. The liquid injection tube is used to inject the electrolyte into the transparent tube.

[0009] In a specific embodiment of the present invention, the liquid injection tube has opposite first communication ports and second communication ports. The first communication port is communicated with the transparent tube.

[0010] The valve assembly includes a first valve. The first valve is arranged on the liquid injection tube, and the first valve is located between the first communication port and the second communication port. The first valve is used to open and close the liquid injection tube.

[0011] In a specific embodiment of the present invention, the valve assembly further includes a liquid injection plug, the liquid injection plug is sealingly connected to the second communication port, and the material of the liquid injection plug is an elastic material;

[0012] The measuring device further includes a syringe, the syringe is used to inject electrolyte into the liquid injection tube, and the liquid injection plug can be punctured through by the syringe.

[0013] In a specific embodiment of the present invention, the transparent tube includes a first tube body, a second tube body and a third tube body. One end of the first tube body along its length direction is connected and communicated with the second tube body, and the other end is connected and communicated with the third tube body. The second tube body and the third tube body are both arranged intersecting with the first tube body, and the second tube body and the third tube body are both located on the same side of the first tube body. The first tube body has the scale. One end of the second tube body along its length direction away from the first tube body is the first connection end, and one end of the third tube body along its length direction away from the first tube body is the second connection end. The liquid injection tube is connected and communicated with the first tube body.

[0014] In a specific embodiment of the present invention, the first tube body is used for vertical arrangement, the second tube body is connected to the lower end of the first tube body, and the liquid injection tube is located between the scale and the second tube body.

[0015] In a specific embodiment of the present invention, the measuring device further includes a second valve and a third valve;

[0016] The second valve is connected to the first connection end, and the second valve is used to connect the first connection end to the battery;

[0017] The third valve is connected to the second connection end, and the third valve is used to connect the second connection end to the battery.

[0018] In a specific embodiment of the present invention, the measuring device further includes a fixture, the fixture has a clamping space, and the clamping space is used to clamp the battery and make at least part of the battery expose outside the clamping space;

[0019] The transparent tube is located outside the clamping space, and both the first connection end and the second connection end are used to connect to the part of the battery that exposes outside the clamping space.

[0020] In a specific embodiment of the present invention, the fixture includes a first clamping plate, a second clamping plate and a connecting piece. The first clamping plate and the second clamping plate are arranged at intervals, and the clamping space is formed between the first clamping plate and the second clamping plate. The connecting piece connects the first clamping plate and the second clamping plate.

[0021] The present invention also provides a method for using the measurement device as described above, which relates to a battery and includes the following steps:

[0022] S1: Connect the first connection end and the second connection end to the battery so that the electrolyte in the battery enters the transparent tube;

[0023] S2: Open the valve assembly and inject a preset amount of electrolyte into the transparent tube through the liquid injection tube. Record the change amount of the first liquid level height of the electrolyte in the transparent tube. Calibrate the change amount of the electrolyte through the injection amount of the electrolyte and the change amount of the first liquid level height. The change amount of the electrolyte refers to how many mass units of electrolyte correspond to a unit liquid level height;

[0024] S3: First discharge the battery to the fully discharged state, and then charge the battery to the fully charged state. Record the change amount of the second liquid level height of the electrolyte in the transparent tube when the battery changes from the fully discharged state to the fully charged state. Obtain the first change amount of the electrolyte in the battery through the change amount of the second liquid level height and the change amount of the electrolyte;

[0025] S4: Discharge the battery to the fully discharged state. Record the change amount of the third liquid level height of the electrolyte in the transparent tube when the battery changes from the fully charged state to the fully discharged state. Obtain the second change amount of the electrolyte in the battery through the change amount of the third liquid level height and the change amount of the electrolyte;

[0026] S5: Compare the first change amount and the second change amount.

[0027] In a specific embodiment of the present invention, in step S3, after the battery reaches the fully charged state, let the battery stand for a first preset time and then record the change amount of the second liquid level height;

[0028] In step S4, after the battery reaches the fully discharged state, let the battery stand for a second preset time and then record the change amount of the third liquid level height.

[0029] The measurement device and the method for using the measurement device according to the embodiments of the present invention have the following beneficial effects compared with the prior art:

[0030] When the measuring device of the present invention is used to measure the extrusion amount and suction amount of the electrolyte in the battery cell, the first connection end and the second connection end of the transparent tube are connected to the battery so that the transparent tube communicates with the battery accommodation cavity, and the transparent tube is placed vertically. At this time, the electrolyte in the battery accommodation cavity will enter the transparent tube, and the scale can indicate the liquid level height of the electrolyte in the transparent tube. Based on the principle of communicating vessels, the liquid levels of the electrolyte in the battery accommodation cavity and the electrolyte in the transparent tube will be kept at the same horizontal plane. After that, the valve assembly is opened, and a preset amount of electrolyte is injected into the transparent tube through the injection tube. Then, the valve assembly is closed, and the change amount of the electrolyte is calibrated by the injection amount of the electrolyte and the change amount of the liquid level height of the electrolyte. After that, the battery is first discharged to full discharge state, and then charged to full charge state. Since the battery cell will expand and extrude the electrolyte in the cell during charging, the electrolyte free outside the cell in the battery accommodation cavity will increase. Therefore, the liquid level of the electrolyte in the transparent tube will rise. Based on this, the change amount of the liquid level height of the electrolyte in the transparent tube when the battery changes from full discharge state to full charge state is recorded. Through the change amount of the electrolyte and the change amount of the liquid level height of the electrolyte, the extrusion amount of the electrolyte in the cell can be obtained; on the contrary, when the battery in full charge state is discharged to full discharge state, the cell will contract and suck back the electrolyte. At this time, the electrolyte free outside the cell in the battery accommodation cavity will decrease, and the liquid level of the electrolyte in the transparent tube will drop. Based on this, the change amount of the liquid level height of the electrolyte in the transparent tube when the battery changes from full charge state to full discharge state is recorded. Through the change amount of the electrolyte and the change amount of the liquid level height of the electrolyte, the suction amount of the electrolyte in the cell can be obtained; in the process of obtaining the extrusion amount and suction amount of the electrolyte in the cell as described above, the electrolyte is completely located in the space formed by the connection of the battery and the transparent tube, and the evaporation amount of the electrolyte is extremely small. Therefore, when using this measuring device to measure the extrusion amount and suction amount of the electrolyte in the cell during the charge and discharge process of the battery, the error of the measurement result is relatively small, and the measurement accuracy is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a perspective view of the measuring device according to an embodiment of the present invention in cooperation with a battery;

[0032] Figure 2 is a side view of the measuring device according to an embodiment of the present invention without the fixture in cooperation with the battery;

[0033] Figure 3 is a flowchart of the usage method of the measuring device according to an embodiment of the present invention.

[0034] In the figure, 10 is the battery; 10A is the accommodation cavity; 1 is the transparent tube; 100 is the scale; 101 is the first connection end; 102 is the second connection end; 11 is the first tube body; 12 is the second tube body; 13 is the third tube body; 2 is the liquid injection tube; 201 is the first communication port; 202 is the second communication port; 3 is the valve assembly; 31 is the first valve; 32 is the liquid injection plug; 4 is the syringe; 5 is the second valve; 6 is the third valve; 7 is the clamp; 701 is the clamping space; 71 is the first clamping plate; 72 is the second clamping plate; 73 is the connecting member; Z is the height direction. Detailed implementation manners

[0035] The following combines the accompanying drawings and embodiments to further describe in detail the specific implementation manners of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0037] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. It may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0038] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0039] In the embodiments of the application, "parallel" means the state where the angle formed by a straight line and a straight line, a straight line and a plane, or a plane and a plane is -1° to 1°. Additionally, "perpendicular" means the state where the angle formed by a straight line and a straight line, a straight line and a plane, or a plane and a plane is 89° to 91°. Equal distance, equal angle or equal area mean the state where the tolerance range is -1% to 1%.

[0040] As Figures 1 to 2 shown, a measuring device of a preferred embodiment of the present invention is used to measure the electrolyte content in the accommodation cavity 10A of the battery 10. The battery 10 has a height direction Z. The measuring device includes a transparent tube 1, a liquid injection tube 2 and a valve assembly 3. The transparent tube 1 has a first connection end 101 and a second connection end 102. The first connection end 101 and the second connection end 102 are respectively used to connect the battery 10 and are arranged at intervals in the height direction Z, and the first connection end 101 and the second connection end 102 communicate with the accommodation cavity 10A. The liquid injection tube 2 is connected to and communicated with the transparent tube 1. The valve assembly 3 is connected to the liquid injection tube 2, and the valve assembly 3 is used to open and close the liquid injection tube 2. Wherein, the outer wall surface of the transparent tube 1 has a scale 100, and the scale 100 is used to mark the liquid level height of the electrolyte in the transparent tube 1. The liquid injection tube 2 is used to inject the electrolyte into the transparent tube 1, so as to calibrate the electrolyte change amount through the injection amount of the electrolyte and the change amount of the liquid level height of the electrolyte. Wherein, the electrolyte change amount refers to how many mass units of electrolyte correspond to a unit liquid level height.

[0041] When using the measuring device of the present invention to measure the extrusion amount and suction amount of the electrolyte in the battery cell of the battery 10, the first connection end 101 and the second connection end 102 of the transparent tube 1 are connected to the battery 10 so that the transparent tube 1 communicates with the accommodation cavity 10A, and the transparent tube 1 is placed vertically. At this time, the electrolyte in the accommodation cavity 10A of the battery 10 will enter the transparent tube 1, and the scale 100 can indicate the liquid level height of the electrolyte in the transparent tube 1. Based on the principle of communicating vessels, the liquid levels of the electrolyte in the accommodation cavity 10A of the battery 10 and the electrolyte in the transparent tube 1 will remain at the same horizontal plane. After that, the valve assembly 3 is opened, and a preset amount of electrolyte is injected into the transparent tube 1 through the liquid injection tube 2. Then, the valve assembly 3 is closed, and the change amount of the electrolyte is calibrated by the injection amount of the electrolyte and the change amount of the liquid level height of the electrolyte. After that, the battery 10 is first discharged to a full discharge state and then charged to a full charge state. Since the battery cell will expand and extrude the electrolyte in the battery cell during charging of the battery 10, the electrolyte free outside the battery cell in the accommodation cavity 10A of the battery 10 will increase. Therefore, the liquid level of the electrolyte in the transparent tube 1 will rise. Based on this, the change amount of the liquid level height of the electrolyte in the transparent tube 1 when the battery 10 changes from the full discharge state to the full charge state is recorded. Through the change amount of the electrolyte and the change amount of the liquid level height of the electrolyte, the extrusion amount of the electrolyte in the battery cell can be obtained; on the contrary, when the fully charged battery 10 is discharged to the full discharge state, the battery cell will contract and suck back the electrolyte. At this time, the electrolyte free outside the battery cell in the accommodation cavity 10A of the battery 10 will decrease, and the liquid level of the electrolyte in the transparent tube 1 will drop. Based on this, the change amount of the liquid level height of the electrolyte in the transparent tube 1 when the battery 10 changes from the full charge state to the full discharge state is recorded. Through the change amount of the electrolyte and the change amount of the liquid level height of the electrolyte, the suction amount of the electrolyte in the battery cell can be obtained; in the process of obtaining the extrusion amount and suction amount of the electrolyte in the battery cell as described above, the electrolyte is completely located in the space formed by the connection of the battery 10 and the transparent tube 1, and the evaporation amount of the electrolyte is extremely small. Therefore, when using this measuring device to measure the extrusion amount and suction amount of the electrolyte in the battery cell during the charge and discharge process of the battery 10, the error of the measurement result is relatively small.

[0042] In this embodiment, as Figure 2 shown, the liquid injection tube 2 has opposite first communication ports 201 and second communication ports 202, and the first communication port 201 communicates with the transparent tube 1; the valve assembly 3 includes a first valve 31, the first valve 31 is arranged on the liquid injection tube 2, and the first valve 31 is located between the first communication port 201 and the second communication port 202. The first valve 31 is used to open and close the liquid injection tube 2. Its structure is simple and easy to install. The setting of the first valve 31 can keep the liquid injection tube 2 in a closed state when no liquid injection is required, avoiding liquid leakage.

[0043] Further, the valve assembly 3 further includes a liquid injection plug 32, which is sealingly connected to the second communication port 202. In some embodiments, as one way of filling the electrolyte, the liquid injection plug 32 can be detached from the second communication port 202, and then the electrolyte can be filled into the transparent tube 1 through the liquid injection tube 2. After the filling is completed, the liquid injection plug 32 is installed on the second communication port 202 to seal the second communication port 202.

[0044] In this embodiment, as Figure 2 shown, the measuring device further includes a syringe 4, which is used to inject electrolyte into the liquid injection tube 2; the liquid injection plug 32 is made of an elastic material and can be punctured through by the syringe 4. Based on this, when filling the electrolyte into the transparent tube 1 through the liquid injection tube 2, the syringe is used to suck the electrolyte, and then the syringe is punctured through the liquid injection plug 32. The liquid injection plug 32 will undergo local deformation under the action of the puncture force, creating a passage for the syringe to enter the liquid injection tube 2, thereby filling the electrolyte into the transparent tube 1. After the filling is completed, the syringe is pulled out from the liquid injection plug 32. Due to its own elasticity, the punctured part of the liquid injection plug 32 will try its best to return to its original shape, filling the hole formed by the puncture, thus re-forming a sealed state, so that the second communication port 202 is sealed again. During this process, there is no need to disassemble and assemble the liquid injection plug 32, which is convenient to operate; exemplarily, the liquid injection plug 32 is made of corrosion-resistant rubber material.

[0045] In this embodiment, as Figures 1 to 2 shown, the transparent tube 1 includes a first tube body 11, a second tube body 12 and a third tube body 13. One end of the first tube body 11 along its length direction is connected and communicated with the second tube body 12, and the other end is connected and communicated with the third tube body 13. The second tube body 12 and the third tube body 13 are both perpendicular to the first tube body 11, and the second tube body 12 and the third tube body 13 are both located on the same side of the first tube body 11. The first tube body 11 has a scale 100. One end of the second tube body 12 along its length direction away from the first tube body 11 is a first connection end 101, and one end of the third tube body 13 along its length direction away from the first tube body 11 is a second connection end 102. The liquid injection tube 2 is connected and communicated with the first tube body 11. Specifically, the first tube body 11 is connected to the battery 10 through the second tube body 12 and the third tube body 13, and the scale 100 is provided on the first tube body 11. The transparent tube 1 with such a structure has a simple structure, which is convenient for production and connection with the battery 10. As a preference of this embodiment, the first tube body 11 is a circular tube, which is convenient for keeping the line of sight perpendicular to the scale 100 line when recording the change amount of the liquid level height during the measurement process, ensuring the accuracy of the reading.

[0046] In practical applications, when measuring the battery 10, the first tube body 11 is arranged vertically. At this time, the second tube body 12 is communicated with the lower end of the battery 10, and the third tube body 13 is communicated with the upper end of the battery 10. As an optimization of this embodiment, as Figure 1 and Figure 2 shown, the second tube body 12 is connected to the lower end of the first tube body 11, and the liquid injection tube 2 is located between the scale 100 and the second tube body 12. Based on this, when injecting the electrolyte into the transparent tube 1 through the liquid injection tube 2, the electrolyte output from the liquid injector can be directly injected into the transparent tube 1 and mixed with the electrolyte in the transparent tube 1, which can avoid the phenomenon of the injected electrolyte sticking to the wall, and can reduce the standing time when calibrating the change amount of the electrolyte.

[0047] Furthermore, as Figure 1 and Figure 2 shown, the measuring device further includes a second valve 5 and a third valve 6; the second valve 5 is connected to the first connection end 101, and the second valve 5 is used to connect the first connection end 101 to the battery 10; the third valve 6 is connected to the second connection end 102, and the third valve 6 is used to connect the second connection end 102 to the battery 10. Specifically, the transparent tube 1 is connected to the battery 10 through the second valve 5 and the third valve 6. The advantage is that when preparing the battery 10 for measurement, the first valve 31, the second valve 5 and the transparent tube 1 can be first connected to the battery 10 without adding electrolyte. At this time, the first valve 31 and the second valve 5 are in the closed state. Then, a preset amount of electrolyte is injected into the battery 10. After the electrolyte in the battery 10 completely wets the battery core, the first valve 31 and the second valve 5 are opened, so that the electrolyte in the battery 10 flows into the transparent tube 1. This is beneficial to ensure that the state of the battery 10 before measurement is maintained in the normal state of the mass-produced battery 10. Using such a battery 10 for measurement is beneficial to ensure the accuracy of the measurement result.

[0048] Furthermore, as Figure 1 and Figure 2 shown, the measuring device further includes a clamp 7. The clamp 7 has a clamping space 701, and the clamping space 701 is used to clamp the battery 10 and make at least a part of the battery 10 exposed outside the clamping space 701; the transparent tube 1 is located outside the clamping space 701, and both the first connection end 101 and the second connection end 102 are used to connect to the part of the battery 10 exposed outside the clamping space 701. Specifically, during the measurement process, the clamp 7 is used to clamp the battery 10, which can effectively ensure that the battery 10 and the transparent tube 1 are in a vertical state and remain stable, reducing the possibility of errors during the measurement process, and is beneficial to ensuring the accuracy of the measurement result.

[0049] As a specific implementation of this embodiment, as Figure 1 and Figure 2As shown in the figure, the fixture 7 includes a first clamping plate 71, a second clamping plate 72 and a connecting member 73. The first clamping plate 71 and the second clamping plate 72 are arranged at intervals, and a clamping space 701 is formed between the first clamping plate 71 and the second clamping plate 72. The connecting member 73 connects the first clamping plate 71 and the second clamping plate 72. Exemplarily, the first clamping plate 71 and the second clamping plate 72 are rectangular, and the connecting member 73 is a bolt, and the number of bolts is four. The four bolts respectively connect the four corners of the first clamping plate 71 and the second clamping plate 72, so as to provide a reliable fixing force to clamp the battery 10.

[0050] Based on the above measurement device, as Figure 3 shown, the present invention also provides a method for using a measurement device, including the following steps:

[0051] S1: Connect the first connection end 101 and the second connection end 102 to the battery 10 so that the electrolyte in the battery 10 enters the transparent tube 1.

[0052] Specifically, the transparent tube 1 and the battery 10 form a communicating vessel. Based on this, place the battery 10 on a horizontal plane and make the part of the transparent tube 1 with the scale 100 extend vertically, so that the liquid level of the electrolyte in the transparent tube 1 is consistent with the liquid level of the electrolyte in the battery 10. It should be noted that the battery 10 includes a housing and an electric core, the housing has the above-mentioned accommodation cavity 10A, and the electric core and the electrolyte are located in the accommodation cavity 10A.

[0053] S2: Open the valve assembly 3, and inject a preset amount of electrolyte into the transparent tube 1 through the liquid injection tube 2, record the change amount of the first liquid level height of the electrolyte in the transparent tube 1, and calibrate the change amount of the electrolyte through the injection amount of the electrolyte and the change amount of the first liquid level height. The change amount of the electrolyte refers to how many mass units of electrolyte correspond to a unit liquid level height.

[0054] Specifically, the change amount of the electrolyte refers to how many mass units of electrolyte correspond to a unit liquid level height. After calibrating the change amount of the electrolyte, by observing the change of the scale 100 on the transparent tube 1, the size of the extrusion amount and the reabsorption amount of the electrolyte in the electric core of the battery 10 during the charge and discharge cycle can be known.

[0055] As a preference of this embodiment, before performing step S3, repeat step S2 multiple times. Exemplarily, slowly inject 0.5 g of electrolyte into the transparent tube 1 through the liquid injection tube 2, mark the change of the liquid level position of the electrolyte in the transparent tube 1 after leaving it for 10 minutes, repeat this behavior multiple times, and calibrate the injection amount of the electrolyte and the change amount of the first liquid level height. Among them, the calibration result is 0.22 g / mm, that is, each millimeter length in the transparent tube 1 corresponds to 0.22 grams of electrolyte.

[0056] S3: First, discharge the battery 10 to the fully discharged state, then charge the battery 10 to the fully charged state, record the change amount of the second liquid level height of the electrolyte in the transparent tube 1 when the battery 10 changes from the fully discharged state to the fully charged state, and obtain the first change amount of the electrolyte in the battery cell of the battery 10 through the change amount of the second liquid level height and the change amount of the electrolyte.

[0057] Specifically, during the process of the battery 10 changing from the fully discharged state to the fully charged state, the battery cell in the battery 10 expands, which squeezes out the electrolyte in the battery cell. The free electrolyte inside the battery 10 increases. At this time, the liquid level of the electrolyte in the transparent tube 1 rises. Therefore, first record the liquid level height of the electrolyte in the transparent tube 1 when the battery 10 is in the fully discharged state, and then record the liquid level height of the electrolyte in the transparent tube 1 when the battery 10 is in the fully charged state. The difference between the two can obtain the above-mentioned change amount of the second liquid level height. Then, obtain the first change amount of the electrolyte in the battery cell of the battery 10 through the change amount of the second liquid level height and the change amount of the electrolyte. This first change amount is the amount of electrolyte squeezed out of the battery cell in the battery 10 during the process of the battery 10 changing from the fully discharged state to the fully charged state.

[0058] S4: Discharge the battery 10 to the fully discharged state, record the change amount of the third liquid level height of the electrolyte in the transparent tube 1 when the battery 10 changes from the fully charged state to the fully discharged state, and obtain the second change amount of the electrolyte in the battery cell of the battery 10 through the change amount of the third liquid level height and the change amount of the electrolyte.

[0059] Specifically, during the process of the battery 10 changing from the fully charged state to the fully discharged state, the battery cell in the battery 10 contracts, and the free electrolyte outside the battery cell inside the battery 10 will be sucked back into the battery cell. At this time, the free electrolyte inside the battery 10 decreases, and the liquid level of the electrolyte in the transparent tube 1 drops. Therefore, record the liquid level height of the electrolyte in the transparent tube 1 when the battery 10 is in the fully discharged state at this time. By subtracting this liquid level height from the liquid level height of the electrolyte in the transparent tube 1 when the battery 10 is in the fully charged state mentioned above, the above-mentioned change amount of the third liquid level height can be obtained. Then, obtain the second change amount of the electrolyte in the battery cell of the battery 10 through the change amount of the third liquid level height and the change amount of the electrolyte. This second change amount is the amount of electrolyte sucked back into the battery cell in the battery 10 during the process of the battery 10 changing from the fully charged state to the fully discharged state.

[0060] S5: Compare the first change amount and the second change amount. Thus, the difference between the amount of electrolyte squeezed out and the amount of electrolyte sucked back of the battery cell in the battery 10 during a single charge and discharge process of the battery 10 can be obtained. This difference provides support for the design and performance optimization of the battery 10, and helps to study the effects of different battery 10 systems, structural angle designs, and cycling steps, etc. on the amount of electrolyte squeezed out and the amount of electrolyte sucked back of the battery cell in the battery 10 during its working process.

[0061] Preferably, in this embodiment, after the battery 10 reaches the full charge state in step S3, the battery 10 is allowed to stand for a first preset time and then the change amount of the second liquid level height is recorded; in step S4, after the battery 10 reaches the full discharge state, the battery 10 is allowed to stand for a second preset time and then the change amount of the third liquid level height is recorded. Thus, the accuracy of the reading of the scale 100 can be ensured, thereby ensuring the accuracy of the measurement result.

[0062] In the present invention, the above measurement method can be applied to the charge and discharge cycle of the battery 10. By repeating the above steps S3 to S5, the extrusion amount and the suction amount of the electrolyte in the battery cell of the single battery 10 during each charge and discharge process can be recorded, and the battery 10 design and performance optimization can also be supported.

[0063] In addition, in the above measurement method of the present application, during the process of obtaining the extrusion amount and the suction amount of the electrolyte in the battery cell, the electrolyte is completely located in the space formed by the connection of the battery 10 and the transparent tube 1, and the evaporation amount of the electrolyte is extremely small. Thus, when using this measurement method to measure the extrusion amount and the suction amount of the electrolyte in the battery cell during the charge and discharge process of the battery 10, the error of the measurement result is relatively small.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A measuring device for measuring the electrolyte content in a receiving cavity (10A) of a battery (10), wherein the battery (10) has a height direction (Z), characterized in that: The measuring device comprises a transparent tube (1), a liquid injection tube (2) and a valve assembly (3); The transparent tube (1) has a first connecting end (101) and a second connecting end (102), the first connecting end (101) and the second connecting end (102) are respectively used to connect to the battery (10) and are arranged at intervals in the height direction (Z), and are both in communication with the accommodating cavity (10A); The liquid injection tube (2) is connected to and communicates with the transparent tube (1); The valve assembly (3) is arranged on the liquid injection pipe (2), and the valve assembly (3) is used to open and close the liquid injection pipe (2); The outer wall surface of the transparent tube (1) has a scale (100), the scale (100) is used to indicate the liquid level of the electrolyte in the transparent tube (1), and the injection tube (2) is used to inject the electrolyte into the transparent tube (1).

2. The measuring device according to claim 1, characterized in that The injection tube (2) has a first communication port (201) and a second communication port (202) which are opposite to each other, and the first communication port (201) is connected to the transparent tube (1); The valve assembly (3) comprises a first valve (31), wherein the first valve (31) is arranged on the liquid injection pipe (2), and the first valve (31) is located between the first communication port (201) and the second communication port (202), and the first valve (31) is used to open and close the liquid injection pipe (2).

3. The measuring device according to claim 2, characterized in that The valve assembly (3) further comprises a liquid injection plug (32), wherein the liquid injection plug (32) is sealingly connected to the second communication port (202), and the material of the liquid injection plug (32) is an elastic material; The measuring device also comprises a syringe (4), wherein the syringe (4) is used to inject electrolyte into the liquid injection tube (2), and the liquid injection plug (32) can be pierced through by the syringe (4).

4. The measuring device according to claim 1, characterized in that The transparent tube (1) comprises a first tube body (11), a second tube body (12) and a third tube body (13); one end of the first tube body (11) along its length direction is connected to and communicated with the second tube body (12), and the other end is connected to and communicated with the third tube body (13); the second tube body (12) and the third tube body (13) are both arranged to intersect with the first tube body (11), and the second tube body (12) and the third tube body (13) are both located on the same side of the first tube body (11); the first tube body (11) has the scale (100); the end of the second tube body (12) along its length direction away from the first tube body (11) is the first connecting end (101); the end of the third tube body (13) along its length direction away from the first tube body (11) is the second connecting end (102); and the injection tube (2) is connected to and communicated with the first tube body (11).

5. The measuring device according to claim 4, characterized in that The first tube body (11) is arranged vertically, the second tube body (12) is connected to the lower end of the first tube body (11), and the injection tube (2) is located between the scale (100) and the second tube body (12).

6. The measuring device according to claim 1, characterized in that The measuring device further comprises a second valve (5) and a third valve (6); The second valve (5) is connected to the first connection end (101), and the second valve (5) is used to connect the first connection end (101) to the battery (10); The third valve (6) is connected to the second connection end (102), and the third valve (6) is used to connect the second connection end (102) to the battery (10).

7. The measuring device according to claim 1, characterized in that The measuring device further comprises a clamp (7), wherein the clamp (7) has a clamping space (701), and the clamping space (701) is used to clamp the battery (10) and allow the battery (10) to be at least partially exposed outside the clamping space (701); The transparent tube (1) is located outside the clamping space (701), and the first connecting end (101) and the second connecting end (102) are both used to connect to the portion of the battery (10) exposed outside the clamping space (701).

8. The measuring device according to claim 7, characterized in that The clamp (7) comprises a first clamping plate (71), a second clamping plate (72) and a connecting member (73); the first clamping plate (71) and the second clamping plate (72) are arranged at an interval, and the clamping space (701) is formed between the first clamping plate (71) and the second clamping plate (72); and the connecting member (73) connects the first clamping plate (71) and the second clamping plate (72).

9. A method for using a measuring device as claimed in any one of claims 1 to 8, involving a battery (10), characterized in that: The steps include: S1: connecting the first connection end (101) and the second connection end (102) to the battery (10), so that the electrolyte in the battery (10) enters the transparent tube (1); S2: opening the valve assembly (3), and injecting a preset amount of electrolyte into the transparent tube (1) through the injection tube (2), recording a first liquid level change of the electrolyte in the transparent tube (1), and calibrating the electrolyte change amount by the electrolyte injection amount and the first liquid level change amount, wherein the electrolyte change amount refers to how many mass units of electrolyte correspond to one unit of liquid level; S3: first discharging the battery (10) to a fully discharged state, then charging the battery (10) to a fully charged state, recording a second liquid level change of the electrolyte in the transparent tube (1) from the fully discharged state to the fully charged state, and obtaining a first change of the electrolyte in the battery (10) through the second liquid level change and the electrolyte change; S4: discharging the battery (10) to a fully discharged state, recording a third liquid level height change of the electrolyte in the transparent tube (1) from the fully charged state to the fully discharged state of the battery (10), and obtaining a second change in the electrolyte in the battery (10) through the third liquid level height change and the electrolyte change; S5: Compare the first change amount and the second change amount.

10. The method for using the measuring device according to claim 9, characterized in that: In step S3, after the battery (10) is fully charged, the battery (10) is allowed to stand for a first preset time and then the second liquid level height change is recorded; In step S4, after the battery (10) reaches a fully discharged state, the battery (10) is allowed to stand for a second preset time and then the third liquid level height change is recorded.

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