A measuring device and a method of using a measuring device

Abstract

The application 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 has a first connecting end and a second connecting end, the first connecting end and the second connecting end are respectively used for connecting batteries and are arranged at intervals in the height direction and are in communication with a containing cavity. The liquid injection tube is connected with the transparent tube and is in communication. The valve assembly is arranged on the liquid injection tube and is used for opening and closing the liquid injection tube. An outer wall surface of the transparent tube is provided with a scale, the scale is used for marking the liquid level height of electrolyte in the transparent tube, and the liquid injection tube is used for adding electrolyte into the transparent tube. The measuring device is used for measuring the extrusion amount and the reabsorption amount of electrolyte in the battery during the charging and discharging process, the error of the measuring result is relatively small, and the measuring precision is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a measuring device and a method for using the measuring device. BACKGROUND

[0002] At present, during the charging and discharging process of the lithium ion battery, the battery cell will have a reversible expansion and contraction breathing behavior, at this time, the electrolyte in the battery cell will experience the process of extrusion and resorption, if the extrusion and resorption amount of the electrolyte do not match, then it is easy to cause the lack of electrolyte in the battery cell, thereby affecting the capacity of the battery. In the related art, since the battery is a sealed structure, the internal electrolyte distribution state cannot be directly observed by the naked eye, therefore, the change amount of the electrolyte in the battery cell is usually measured by collecting the free electrolyte through the destructive behavior of disassembling the battery, however, since the electrolyte is extremely volatile, the measurement result has a great error by this way, which is not conducive to evaluating the use performance of the battery. SUMMARY

[0003] The primary object of the present application is to provide a measuring device for measuring the extrusion and resorption amount of the electrolyte in the battery cell during the charging and discharging process of the battery, thereby improving the measurement accuracy.

[0004] In order to achieve the above object, the present application provides a measuring device for measuring the electrolyte content in the accommodating cavity of a battery, the battery has a height direction, the measuring device comprises a transparent tube, a liquid injection tube and a valve assembly;

[0005] The transparent tube has a first connecting end and a second connecting end, the first connecting end and the second connecting end are respectively used for connecting the battery and are arranged at intervals in the height direction and are in communication with the accommodating cavity;

[0006] The liquid injection tube is connected with the transparent tube and is in communication;

[0007] The valve assembly is arranged on the liquid injection tube, and the valve assembly is used for opening and closing the liquid injection tube;

[0008] The outer wall surface of the transparent tube has a scale, the scale is used for indicating the liquid level height of the electrolyte in the transparent tube, and the liquid injection tube is used for adding electrolyte into the transparent tube.

[0009] In a specific embodiment of the present application, the liquid injection tube has opposite first and second communication ports, the first communication port is in communication with the transparent tube;

[0010] The valve assembly comprises 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, and the first valve is used for opening and closing the liquid injection tube.

[0011] In one specific embodiment of the present application, the valve assembly further comprises a liquid injection plug, which is sealingly connected to the second communication port, and the liquid injection plug is made of elastic material.

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

[0013] In one specific embodiment of the present application, the transparent tube comprises 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 to and in communication with the second tube body, and the other end is connected to and in communication with the third tube body, the second tube body and the third tube body are arranged to intersect with the first tube body, and the second tube body and the third tube body are 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 connecting end, and one end of the third tube body along its length direction away from the first tube body is the second connecting end, and the liquid injection tube is connected to and in communication with the first tube body.

[0014] In one specific embodiment of the present application, 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 one specific embodiment of the present application, the measuring device further comprises a second valve and a third valve.

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

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

[0018] In one specific embodiment of the present application, the measuring device further comprises a clamp, which has a clamping space, and the clamping space is used to clamp the battery and make the battery at least partially exposed outside the clamping space.

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

[0020] In one specific embodiment of the present application, the clamp comprises a first clamping plate, a second clamping plate and a connecting piece, the first clamping plate and the second clamping plate are arranged in a spaced manner, and the clamping space is formed between the first clamping plate and the second clamping plate, and the connecting piece connects the first clamping plate and the second clamping plate.

[0021] The application further provides a method for using the measuring device, and relates to a battery, and comprises the following steps:

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

[0023] S2: opening the valve assembly, adding a preset amount of electrolyte to the transparent tube through the liquid injection tube, recording a first liquid level height change amount of the electrolyte in the transparent tube, calibrating an electrolyte change amount through the added amount of electrolyte and the first liquid level height change amount, the electrolyte change amount refers to how many mass units of electrolyte correspond to one unit of liquid level height;

[0024] S3: discharging the battery to a full discharge state, charging the battery to a full charge state, recording a second liquid level height change amount of the electrolyte in the transparent tube from the full discharge state to the full charge state, and obtaining a first change amount of the electrolyte in the battery through the second liquid level height change amount and the electrolyte change amount;

[0025] S4: discharging the battery to a full discharge state, recording a third liquid level height change amount of the electrolyte in the transparent tube from the full charge state to the full discharge state, and obtaining a second change amount of the electrolyte in the battery through the third liquid level height change amount and the electrolyte change amount;

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

[0027] In a specific embodiment of the application, in step S3, after the battery is in the full charge state, the battery is allowed to stand for a first preset time, and then the second liquid level height change amount is recorded;

[0028] In step S4, after the battery is in the full discharge state, the battery is allowed to stand for a second preset time, and then the third liquid level height change amount is recorded.

[0029] Compared with the prior art, the measuring device and the method for using the measuring device have the following beneficial effects:

[0030] The measuring device of the present application, when measuring the extrusion and suction amount of electrolyte in the battery cell, connects the first connecting end and the second connecting end of the transparent tube to the battery, so that the transparent tube communicates with the battery cavity, and the transparent tube is placed in the vertical direction. At this time, the electrolyte in the battery cavity will enter the transparent tube, and the scale can indicate the liquid level of the electrolyte in the transparent tube. Based on the principle of communicating vessels, the liquid levels of the electrolyte in the battery cavity and the transparent tube will remain at the same level. Thereafter, the valve assembly is opened, and a predetermined amount of electrolyte is injected into the transparent tube through the liquid injection pipe. Then, the valve assembly is closed, and the electrolyte change amount is calibrated by the injection amount of electrolyte and the change amount of the liquid level of electrolyte. Thereafter, the battery is first placed in the full discharge state, and then charged to the full charge state. Since the battery cell will expand and extrude the electrolyte in the battery cell when charging, the electrolyte free in the battery cavity will increase, and the liquid level of the electrolyte in the transparent tube will rise. Based on this, the change amount of the liquid level of the electrolyte in the transparent tube from the full discharge state to the full charge state is recorded. The extrusion amount of electrolyte in the battery cell can be obtained by the electrolyte change amount and the change amount of the liquid level of electrolyte. Conversely, the battery is discharged from the full charge state to the full discharge state, and the battery cell will shrink and suck the electrolyte. At this time, the electrolyte free in the battery cavity will decrease, and the liquid level of the electrolyte in the transparent tube will decrease. Based on this, the change amount of the liquid level of the electrolyte in the transparent tube from the full charge state to the full discharge state is recorded. The suction amount of electrolyte in the battery cell can be obtained by the electrolyte change amount and the change amount of the liquid level of electrolyte. In the process of obtaining the extrusion and suction amount of electrolyte in the battery cell, the electrolyte is completely located in the space formed by the communication of the battery and the transparent tube, and the evaporation amount of the electrolyte is very small. Therefore, the measuring device is used to measure the extrusion and suction amount of electrolyte in the battery cell during charging and discharging, and the error of the measurement result is relatively small, and the measurement accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a perspective view of the measuring device of the present application in cooperation with the battery;

[0032] Figure 2 is a side view of the measuring device of the present application in cooperation with the battery without the clamp;

[0033] Figure 3 is a flow chart of the use method of the measuring device of the present application.

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

[0035] The specific embodiments of the present application will be further described in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0037] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the embodiments of the application, "parallel" refers to a state in which the angle formed by two lines, a line and a surface, or a surface is -1° to 1°. "Perpendicular" refers to a state in which the angle formed by two lines, a line and a surface, or a surface is 89° to 91°. Equal distances, equal angles, or equal areas refer to a state in which the tolerance range is -1% to 1%.

[0040] like Figures 1 to 2 As shown, a preferred embodiment of the present invention provides a measuring device for measuring the electrolyte content in a receiving cavity 10A of a battery 10. The battery 10 has a height direction Z. The measuring device includes a transparent tube 1, an 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 spaced apart in the height direction Z. The first connecting end 101 and the second connecting end 102 are in communication with the receiving cavity 10A. Liquid tube 2 is connected to and conducts through transparent tube 1; valve assembly 3 is connected to injection tube 2, and valve assembly 3 is used to open and close injection tube 2; wherein, the outer wall surface of transparent tube 1 has a scale 100, which is used to indicate the liquid level height of electrolyte in transparent tube 1, and injection tube 2 is used to inject electrolyte into transparent tube 1, so as to calibrate the change in electrolyte by the amount of electrolyte added and the change in liquid level height, wherein the change in electrolyte refers to how many mass units of electrolyte correspond to one unit of liquid level height.

[0041] The measuring device of the present application is used to measure the extrusion and suction amount of the electrolyte in the battery 10. The first connecting end 101 and the second connecting end 102 of the transparent tube 1 are connected to the battery 10, so that the transparent tube 1 is in communication with the accommodating cavity 10A of the battery 10, and the transparent tube 1 is placed in the vertical direction. At this time, the electrolyte in the accommodating cavity 10A of the battery 10 enters the transparent tube 1, and the scale 100 can indicate the liquid level of the electrolyte in the transparent tube 1. Based on the principle of communicating vessels, the liquid levels of the electrolyte in the accommodating cavity 10A of the battery 10 and the electrolyte in the transparent tube 1 are kept at the same level. Then, the valve assembly 3 is opened, and the predetermined 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 of the electrolyte. Then, the battery 10 is first placed in the full discharge state, and then charged to the full charge state. When the battery 10 is charged, the battery cell will expand and extrude the electrolyte in the battery cell. The free electrolyte outside the battery cell in the accommodating cavity 10A of the battery 10 will increase, so the liquid level of the electrolyte in the transparent tube 1 will rise. Based on this, the change amount of the liquid level of the electrolyte in the transparent tube 1 from the full discharge state to the full charge state of the battery 10 is recorded. The extrusion amount of the electrolyte in the battery cell can be obtained by the change amount of the electrolyte and the change amount of the liquid level of the electrolyte. Conversely, the battery 10 in the full charge state is discharged to the full discharge state, and the battery cell will shrink and suck the electrolyte. At this time, the free electrolyte outside the battery cell in the accommodating cavity 10A of the battery 10 will decrease, and the liquid level of the electrolyte in the transparent tube 1 will decrease. Based on this, the change amount of the liquid level of the electrolyte in the transparent tube 1 from the full charge state to the full discharge state of the battery 10 is recorded. The suction amount of the electrolyte in the battery cell can be obtained by the change amount of the electrolyte and the change amount of the liquid level of the electrolyte. In the process of obtaining the extrusion and suction amount of the electrolyte in the battery cell, the electrolyte is completely located in the space formed by the communication of the battery 10 and the transparent tube 1, and the volatilization amount of the electrolyte is very small. Therefore, the measuring device is used to measure the extrusion and suction amount of the electrolyte in the battery cell during the charging and discharging process of the battery 10, and the error of the measurement result is relatively small.

[0042] In the present embodiment, as shown in Figure 2 The liquid injection tube 2 has opposite first and second communicating openings 201 and 202, and the first communicating opening 201 is in communication with the transparent tube 1. The valve assembly 3 includes a first valve 31 arranged on the liquid injection tube 2 and located between the first and second communicating openings 201 and 202. The first valve 31 is used to open and close the liquid injection tube 2. The structure is simple, and the installation is convenient. The first valve 31 can keep the liquid injection tube 2 closed when no liquid is injected, so as to avoid liquid leakage.

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

[0044] In the embodiment, as shown in Figure 2 the measuring device further comprises a syringe 4 for injecting electrolyte into the liquid injection tube 2. The liquid injection plug 32 is made of elastic material and can be pierced by the syringe 4. Based on this, when adding electrolyte into the transparent tube 1 through the liquid injection tube 2, the syringe is used to suck electrolyte, and then the syringe pierces the liquid injection plug 32. The liquid injection plug 32 will be locally deformed under the action of the piercing force to allow the syringe to enter the liquid injection tube 2, thereby adding electrolyte into the transparent tube 1. After the addition of electrolyte is completed, the syringe is pulled out of the liquid injection plug 32. Based on the elasticity of the liquid injection plug 32, the pierced part will try to restore to the original shape to fill the hole formed by the piercing, thereby re-forming a sealed state, so that the second communication port 202 is sealed again. In this process, the liquid injection plug 32 does not need to be disassembled, and the operation is convenient. Exemplarily, the liquid injection plug 32 is made of corrosion-resistant rubber material.

[0045] In the embodiment, as shown in Figures 1 to 2 the transparent tube 1 comprises a first tube body 11, a second tube body 12 and a third tube body 13. The first tube body 11 is connected and communicated with the second tube body 12 at one end along the length direction of the first tube body 11 and is connected and communicated with the third tube body 13 at the other end. The second tube body 12 and the third tube body 13 are both perpendicular to the first tube body 11 and are both located on the same side of the first tube body 11. The first tube body 11 has a scale 100. The second tube body 12 has a first connecting end 101 at one end along the length direction of the second tube body 12 away from the first tube body 11. The third tube body 13 has a second connecting end 102 at one end along the length direction of the third tube body 13 away from the first tube body 11. The liquid injection tube 2 is connected and communicated with the first tube body 11. Specifically, the first tube body 11 is connected with the battery 10 through the second tube body 12 and the third tube body 13, and the scale 100 is arranged on the first tube body 11. The transparent tube 1 with such a structure is simple in structure, convenient to produce and connect with the battery 10. As a preferred embodiment, the first tube body 11 is a circular tube, which is convenient for keeping the line of sight perpendicular to the scale 100 during the measurement of the liquid level height change, thereby ensuring the accuracy of the reading.

[0046] In actual application, the first tube body 11 is arranged vertically when the battery 10 is measured, at this time, the second tube body 12 communicates with the lower end of the battery 10, the third tube body 13 communicates with the upper end of the battery 10, as preferred in this embodiment, as shown in Figure 1 and Figure 2 , the second tube body 12 is connected with the lower end of the first tube body 11, the liquid injection tube 2 is located between the scale 100 and the second tube body 12, based on this, when electrolyte is injected 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, the injected electrolyte can be prevented from appearing wall-hanging phenomenon, and the standing time can be reduced when the electrolyte variation amount is calibrated.

[0047] Further, as shown in Figure 1 and Figure 2 , the measuring device further comprises a second valve 5 and a third valve 6; the second valve 5 is connected to the first connecting end 101, and the second valve 5 is used to connect the first connecting end 101 to the battery 10; the third valve 6 is connected to the second connecting end 102, and the third valve 6 is used to connect the second connecting 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, and the advantage is that when the battery 10 for measurement is prepared, the first valve 31, the second valve 5 and the transparent tube 1 can be connected to the battery 10 without electrolyte injection at this time, at this time, the first valve 31 and the second valve 5 are in a closed state, then a predetermined amount of electrolyte is injected into the battery 10, and the first valve 31 and the second valve 5 are opened after the electrolyte in the battery 10 fully wets the battery cell, so that the electrolyte in the battery 10 flows into the transparent tube 1, which is conducive to maintaining the state of the battery 10 before measurement in the normal state of the mass-produced battery 10, and using such a battery 10 for measurement is conducive to ensuring the accuracy of the measurement result.

[0048] Further, as shown in Figure 1 and Figure 2 , the measuring device further comprises a clamp 7, the clamp 7 has a clamping space 701, the clamping space 701 is used to clamp the battery 10 and make the battery 10 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 with the part of the battery 10 exposed outside the clamping space 701, specifically, in 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, reduce the possibility of error in the measurement process, and is conducive to ensuring the accuracy of the measurement result.

[0049] As a specific implementation of this embodiment, as shown in Figure 1 and Figure 2As shown, the clamp 7 comprises a first clamping plate 71, a second clamping plate 72, and a connecting piece 73, the first clamping plate 71 and the second clamping plate 72 are arranged in a spaced manner, and a clamping space 701 is formed between the first clamping plate 71 and the second clamping plate 72, the connecting piece 73 connects the first clamping plate 71 and the second clamping plate 72, and the first clamping plate 71 and the second clamping plate 72 are rectangular, and the connecting piece 73 is a bolt, and the number of the bolt is four, and the four bolts are connected to four corners of the first clamping plate 71 and the second clamping plate 72 respectively, so that reliable fixing force can be provided to clamp the battery 10.

[0050] Based on the above measuring device, as shown, Figure 3 The application further provides a use method of the measuring device, comprising the following steps:

[0051] S1: connecting the first connecting end 101 and the second connecting 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 constitute a communication device, based on this, the battery 10 is placed on a horizontal plane, and the part of the transparent tube 1 provided with the scale 100 is vertically extended, so that the electrolyte liquid level in the transparent tube 1 is consistent with the electrolyte liquid level in the battery 10; it should be noted that the battery 10 comprises a shell and a battery core, and the shell has the above-mentioned accommodating cavity 10A, and the battery core and the electrolyte are located in the accommodating cavity 10A.

[0053] S2: opening the valve assembly 3, and adding a preset amount of electrolyte to the transparent tube 1 through the liquid injection tube 2, recording the first liquid level height change of the electrolyte in the transparent tube 1, and calibrating the electrolyte change amount through the adding amount of the electrolyte and the first liquid level height change, the electrolyte change amount refers to how many mass units of electrolyte correspond to one unit of liquid level height.

[0054] Specifically, the electrolyte change amount refers to how many mass units of electrolyte correspond to one unit of liquid level height, after the electrolyte change amount is calibrated, the size of the electrolyte extrusion amount and the electrolyte suction amount of the battery core in the battery 10 during the charging and discharging cycle can be known by observing the scale 100 change on the transparent tube 1.

[0055] As a preferred embodiment of the present embodiment, before step S3 is performed, step S2 is repeated multiple times; for example, 0.5g of electrolyte is slowly added to the transparent tube 1 through the liquid injection tube 2, and the electrolyte liquid level position change of the transparent tube 1 is marked after 10 minutes of standing, and the above-mentioned behavior is repeated multiple times, and the adding amount of the electrolyte and the first liquid level height change are calibrated, wherein the calibration result is 0.22g / mm, that is, 0.22g of electrolyte corresponds to one millimeter length in the transparent tube 1.

[0056] S3: first discharge the battery 10 to the full discharge state, then charge the battery 10 to the full charge state, record the second liquid level height change of the electrolyte in the transparent tube 1 from the full discharge state to the full charge state, and obtain the first change of the electrolyte in the battery 10 through the second liquid level height change and the electrolyte change.

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

[0058] S4: discharge the battery 10 to the full discharge state, record the third liquid level height change of the electrolyte in the transparent tube 1 from the full charge state to the full discharge state, and obtain the second change of the electrolyte in the battery 10 through the third liquid level height change and the electrolyte change.

[0059] Specifically, during the process of the battery 10 from the full charge state to the full discharge state, the battery 10 shrinks, which will suck the electrolyte in the battery 10 back into the battery 10. At this time, the free electrolyte in the battery 10 decreases, and the liquid level of the electrolyte in the transparent tube 1 decreases. Therefore, the liquid level of the electrolyte in the transparent tube 1 when the battery 10 is in the full discharge state is recorded. The difference between the liquid level and the liquid level of the electrolyte in the transparent tube 1 when the battery 10 is in the full charge state can obtain the above-mentioned third liquid level height change. Then, the second change of the electrolyte in the battery 10 is obtained through the third liquid level height change and the electrolyte change. The second change is the amount of electrolyte sucked back into the battery 10 during the process of the battery 10 from the full charge state to the full discharge state.

[0060] S5: compare the first change and the second change, thereby obtaining the difference between the amount of electrolyte squeezed out of the battery 10 and the amount of electrolyte sucked back into the battery 10 during the single charging and discharging process of the battery 10. Through the difference, support is provided for the design and performance optimization of the battery 10, which helps to study the influence of different battery 10 systems, structural angle designs, and cycle steps on the amount of electrolyte squeezed out of the battery 10 and the amount of electrolyte sucked back into the battery 10 during the working process of the battery 10.

[0061] As preferred in the embodiment, after the battery 10 is charged to the full state in step S3, the battery 10 is allowed to stand for a first preset time before recording the second liquid level change amount; and after the battery 10 is discharged to the full state in step S4, the battery 10 is allowed to stand for a second preset time before recording the third liquid level change amount. In this way, the accuracy of the scale 100 reading can be ensured, and thus the accuracy of the measurement result can be ensured.

[0062] In the present application, the above measurement method can be applied in the charge-discharge cycle of the battery 10. By repeating the above steps S3 to S5, the amount of electrolyte squeezed out and sucked back in the single battery 10 in each charge-discharge process can be recorded, and thus support can be provided for the design and performance optimization of the battery 10.

[0063] In addition, in the above measurement method, the electrolyte is completely located in the space formed by the communication between the battery 10 and the transparent tube 1 during the process of obtaining the amount of electrolyte squeezed out and sucked back, and the amount of electrolyte volatilized is extremely small. Therefore, when the measurement method is used to measure the amount of electrolyte squeezed out and sucked back in the battery 10 in the charge-discharge process, the error of the measurement result is relatively small.

[0064] The above description is only preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and replacements without departing from the technical principles of the present application. These improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A measuring device for measuring the electrolyte content in a housing cavity (10A) of a battery (10) having a height direction (Z), characterized by 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 for connecting the battery (10) and are arranged at intervals in the height direction (Z) and are in communication with the accommodating cavity (10A); The liquid injection tube (2) is connected with the transparent tube (1) and is in communication; The valve assembly (3) is arranged on the liquid injection tube (2), and the valve assembly (3) is used for opening and closing the liquid injection tube (2); The outer wall surface of the transparent tube (1) has a scale (100), the scale (100) is used for indicating the liquid level of the electrolyte in the transparent tube (1), and the liquid injection tube (2) is used for adding electrolyte into the transparent tube (1); The liquid injection tube (2) has opposite first and second communication openings (201) and (202), the first communication opening (201) is in communication with the transparent tube (1); The valve assembly (3) comprises 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 and second communication openings (201) and (202), and the first valve (31) is used for opening and closing the liquid injection tube (2); The valve assembly (3) further comprises a liquid injection plug (32), the liquid injection plug (32) is sealingly connected to the second communication opening (202), and the material of the liquid injection plug (32) is an elastic material; The measuring device further comprises a syringe (4), the syringe (4) is used for injecting electrolyte into the liquid injection tube (2), and the liquid injection plug (32) can be pierced by the syringe (4).

2. The measuring device of claim 1, wherein, 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 with the second tube body (12) and is in communication, the other end is connected with the third tube body (13) and is in communication, the second tube body (12) and the third tube body (13) are arranged intersecting the first tube body (11), and the second tube body (12) and the third tube body (13) are located on the same side of the first tube body (11), the first tube body (11) has the scale (100), one end of the second tube body (12) away from the first tube body (11) along its length direction is the first connecting end (101), one end of the third tube body (13) away from the first tube body (11) along its length direction is the second connecting end (102), and the liquid injection tube (2) is connected with the first tube body (11) and is in communication.

3. The measuring device of claim 2, wherein, The first tube body (11) is used for vertical arrangement, the second tube body (12) is connected with 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).

4. The measuring device of claim 1, wherein, The measuring device further comprises a second valve (5) and a third valve (6); The second valve (5) is connected to the first connecting end (101), and the second valve (5) is used to connect the first connecting end (101) to the battery (10); The third valve (6) is connected to the second connecting end (102), and the third valve (6) is used to connect the second connecting end (102) to the battery (10).

5. The measuring device of claim 1, wherein, The measuring device further comprises a clamp (7) having a clamping space (701) for clamping the battery (10) and exposing the battery (10) at least partially 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 with the part of the battery (10) exposed outside the clamping space (701).

6. The measuring device of claim 5, wherein, The clamp (7) comprises a first clamping plate (71), a second clamping plate (72), and a connecting piece (73), the first clamping plate (71) and the second clamping plate (72) are arranged in a spaced manner, and the clamping space (701) is formed between the first clamping plate (71) and the second clamping plate (72), and the connecting piece (73) connects the first clamping plate (71) and the second clamping plate (72).

7. A method of using a measuring device according to any of claims 1-6, in connection with a battery (10), characterized in that, The method comprises the following steps: S1: connecting the first connecting end (101) and the second connecting end (102) to the battery (10) to make the electrolyte in the battery (10) enter the transparent tube (1); S2: opening the valve assembly (3), and adding a preset amount of electrolyte to the transparent tube (1) through the liquid injection tube (2), recording the first liquid level height change of the electrolyte in the transparent tube (1), and calibrating the electrolyte change amount by the added amount of electrolyte and the first liquid level height change, the electrolyte change amount refers to how many mass units of electrolyte correspond to one unit of liquid level height; S3: discharging the battery (10) to a full discharge state, and then charging the battery (10) to a full charge state, recording the second liquid level height change of the electrolyte in the transparent tube (1) from the full discharge state to the full charge state of the battery (10), and obtaining the first change amount of the electrolyte in the battery (10) by the second liquid level height change and the electrolyte change amount; S4: discharging the battery (10) to a full discharge state, recording the third liquid level height change of the electrolyte in the transparent tube (1) from the full charge state to the full discharge state of the battery (10), and obtaining the second change amount of the electrolyte in the battery (10) by the third liquid level height change and the electrolyte change amount; S5: comparing the first change amount and the second change amount.

8. The method of using a measuring device of claim 7, wherein, In step S3, after the battery (10) reaches the full charge state, the battery (10) is allowed to stand for a first preset time before recording the second liquid level height change; In step S4, after the battery (10) is brought to a full discharge state, the battery (10) is left to stand for a second predetermined time, and the third liquid level height change amount is recorded again.

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