Battery pole piece thickness testing device

Abstract

The utility model relates to the technical field of battery pole piece production, and discloses a battery pole piece thickness testing device which comprises a sealed container and a pressing plate, a battery pole piece is arranged in the sealed container, the pressing plate is arranged on the upper surface of the battery pole piece, and a liquid injection port for injecting electrolyte into the sealed container is arranged on the sealed container. In other words, external electrolyte is injected into the sealed container through the liquid injection port, flows to the periphery through the pressing plate and permeates into the pole piece, so that the pole piece reaches a wet state; an induction measuring unit is also arranged in the sealed container and is used for detecting the displacement variation of the pressing plate in the thickness direction of the battery pole piece, that is, the thickness of the pole piece is changed along with the prolonging of the infiltration time of the pole piece and acts on the pressing plate, so that the pressing plate is driven to generate displacement in the thickness direction; therefore, the swelling thickness of the battery pole piece can be obtained by automatically sensing and measuring the thickness variation of the pressing plate through the sensing and measuring unit, and meanwhile, the thickness variation trend of the battery pole piece can be monitored in real time.

Description

Technical Field

[0001] The utility model relates to the technical field of battery pole piece production, in particular to a battery pole piece thickness testing device. Background Art

[0002] In the production process of lithium-ion batteries, the thickness of the battery pole piece has a crucial impact on the capacity decay and rate performance of the battery cell, and determines the performance indicators of the lithium-ion battery such as capacity, weight, and energy density. Therefore, it is extremely important to accurately measure the thickness of the positive / negative pole piece during the battery cell manufacturing process.

[0003] The existing measuring tool for measuring the thickness of battery pole pieces is usually a micrometer. The specific test steps are: first use a micrometer to measure the initial thickness d0 of the pole piece, then inject electrolyte into the battery, and after immersion for 3 days, disassemble the battery, take out the pole piece (positive or negative pole piece), and use a micrometer to measure the pole piece thickness d1 again. d1 / d0 is the expansion rate of the pole piece. Although this method can obtain the swelling thickness of the pole piece to a certain extent, due to the certain non-uniformity of the pole piece thickness, when selecting different measurement points, there is a certain error in the thickness tested with a micrometer, and different operators before and after will also bring certain errors. The trend of the pole piece thickness change cannot be measured during the whole process, and it is impossible to achieve real-time measurement of the pole piece thickness change. Utility Model Content

[0004] One of the main purposes of the utility model is to provide a battery pole piece thickness testing device, aiming to solve the existing technical problem that due to the certain unevenness of the pole piece thickness, when different measuring points are selected, the thickness tested by the micrometer has a certain error, and different operators before and after will also bring certain errors, making it impossible to measure the change of the pole piece thickness in real time.

[0005] In order to achieve the above-mentioned purpose of the utility model, the utility model provides a battery pole piece thickness testing device, including a sealed container and a pressing plate, the sealed container is used to place the battery pole piece, the pressing plate is used to be placed on the upper surface of the battery pole piece, the sealed container is provided with a liquid injection port for injecting electrolyte into the sealed container, and the sealed container is also provided with an inductive measurement unit, and the inductive measurement unit is used to detect the displacement change of the pressing plate in the thickness direction of the battery pole piece.

[0006] Furthermore, the sealed container is provided with an air extraction port, and the air extraction port is used to be connected to a vacuum extraction device outside the sealed container.

[0007] Furthermore, the inductive measurement unit includes a displacement sensor, and the displacement sensor is arranged on an upper wall in the sealed container.

[0008] Furthermore, the liquid injection port is arranged above the pressure plate, the lower surface of the pressure plate is a plane that fits the upper surface of the battery electrode, and a drainage part is provided on the upper surface of the pressure plate, and the drainage is used to drain the electrolyte to the battery electrode.

[0009] Furthermore, the inductive measurement unit includes a displacement sensor, which is arranged on the upper wall of the sealed container. A boss is provided on the drainage portion, and the upper surface of the boss is parallel to the battery electrode. The displacement sensor is used to measure the displacement change of the boss in the thickness direction of the battery electrode.

[0010] Furthermore, the pressing plate is in the shape of a quadrangular pyramid, and the slope surface of the quadrangular pyramid forms the drainage portion.

[0011] Furthermore, the boss is slidably disposed on the pressure plate along the inclination direction of the slope surface, and the displacement sensor is movably disposed on the sealed container so that the displacement sensor can change with the position of the boss.

[0012] Furthermore, the displacement sensor can be slidably disposed on the sealed container, and the sliding direction of the displacement sensor is parallel to the battery electrode.

[0013] Furthermore, at least two opposite slope surfaces of the quadrangular pyramid are provided with bosses, and a plurality of displacement sensors are provided, and the plurality of bosses correspond one to one with the plurality of displacement sensors; and the two bosses are symmetrical about the center point of the pressure plate.

[0014] Furthermore, a slot is provided on the slope surface, and the boss is slidably connected to the slot.

[0015] Compared with the prior art, the battery pole thickness testing device of the utility model has the following beneficial effects:

[0016] When the battery pole piece thickness testing device of the utility model is in use, the battery pole piece is horizontally placed on the bottom wall in the sealed container, and then the pressing plate is placed on the upper surface of the battery pole piece, and the external electrolyte is injected into the sealed container through the liquid injection port, and the electrolyte flows to the surroundings through the pressing plate and penetrates into the pole piece, so that the pole piece reaches a wetting state. As the pole piece immersion time increases, the pole piece thickness changes and acts on the pressing plate, driving the pressing plate to produce displacement in the thickness direction. Finally, the thickness change of the pressing plate is automatically sensed and measured by the induction measuring unit to obtain the swelling thickness of the battery pole piece, without manual measurement, thereby overcoming the defects in the prior art that the thickness of the pole piece has a certain non-uniformity, when different measuring points are selected, the thickness tested by the micrometer has a certain error, and different operators before and after will also bring certain errors. In addition, in the process of wetting the battery pole piece, the utility model can also measure the thickness change trend of the battery pole piece in real time, and provide certain data support for studying the thickness of the battery pole piece and the thickness of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a battery electrode thickness testing device of the utility model;

[0018] Figure 2 This is a schematic diagram of the structure of a pressing plate according to an embodiment of the utility model;

[0019] Figure 3 This is a top view of a pressing plate according to an embodiment of the utility model;

[0020] Figure 4 This is a schematic diagram of the structure of a single-chip battery according to an embodiment of the utility model.

[0021] Numbers in the attached drawings:

[0022] 1. Sealed container; 10. Liquid filling port; 11. Air extraction port; 12. Inductive measuring unit; 2. Battery electrode; 3. Press plate; 30. Slope surface; 31. Boss; 32. Slot; 4. Positive electrode; 41. Diaphragm; 42. Negative electrode. DETAILED DESCRIPTION

[0023] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] In the description of the present invention, it should be understood that the terms "length", "up", "down", "front", "back", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 on the present invention.

[0025] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] Please refer to Figure 1-Figure 3The utility model provides a battery pole piece thickness testing device, including a sealed container 1 and a pressing plate 3, the sealed container 1 is used to set the battery pole piece 2, the pressing plate 3 is used to be placed on the upper surface of the battery pole piece 2, the battery pole piece 2 is horizontally arranged in the sealed container 1, the pressing plate 3 is placed on the upper surface of the battery pole piece 2, the sealed container 1 is provided with a liquid injection port 10 for injecting electrolyte into the sealed container 1, and the sealed container 1 is also provided with an inductive measuring unit 12, and the inductive measuring unit 12 is used to detect the displacement change of the pressing plate 3 in the thickness direction of the battery pole piece 2. It can be seen that when the battery electrode 2 thickness testing device of the utility model is in use, the battery electrode 2 is horizontally placed on the bottom wall of the sealed container 1, leaving a gap between the battery electrode 2 and the inner wall of the sealed container 1, and then the pressing plate 3 is placed on the upper surface of the battery electrode 2. Of course, there is also a gap between the pressing plate 3 and the inner wall of the sealed container 1. In this way, after the external electrolyte is injected into the sealed container 1 through the injection port 10, it flows to the surrounding area through the pressing plate 3 and penetrates into the battery electrode 2, so that the battery electrode 2 reaches a wet state; as the infiltration time of the battery electrode 2 increases, the thickness of the battery electrode 2 changes, and acts on the pressing plate 3, driving the pressing plate 3 generates displacement in the thickness direction, and finally the thickness change of the pressing plate 3 is measured by the inductive measuring unit 12 to obtain the swelling thickness of the battery pole piece 2, without manual measurement, which overcomes the problem in the prior art that the thickness of the battery pole piece has a certain unevenness. When different measuring points are selected, the thickness tested by the micrometer has a certain error, and different operators before and after will also bring certain error defects; in addition, in the process of soaking the battery pole piece 2, the inductive measuring unit 12 can also measure the thickness change trend of the battery pole piece 2 in real time, monitor the thickness change trend of the pole piece over time throughout the process, and provide certain data support for studying the thickness of the battery pole piece 2 and the thickness of the battery cell.

[0028] It should be noted that the liquid level of the electrolyte in the sealed container 1 will not exceed the thickness of the battery electrode 2, so as to ensure that the battery electrode 2 and the pressure plate 3 will not generate buoyancy due to the electrolyte; wherein, the amount of electrolyte injected into the sealed container 1 can be controlled by the operator, for example, by injecting the electrolyte into the sealed container 1 through a quantitative syringe; the required amount of electrolyte is roughly calculated by the formula m=PV (V=container bottom area S*electrode plate thickness d), and then the corresponding amount of electrolyte is injected through a quantitative syringe.

[0029] In one embodiment, the sealed container 1 is also sealed with an air extraction port 11, and the air extraction port 11 is connected to a vacuum extraction device outside the sealed container 1. It can be seen that the process of measuring the thickness of the battery pole piece 2 is carried out in a vacuum environment, so as to avoid the influence of the external environment on the measurement result. Specifically, in the process of wetting the battery pole piece 2, the vacuum extraction device makes the sealed environment inside the sealed container 1 reach a vacuum condition through the air extraction port 11. Under the vacuum environment, the electrolyte is injected into the sealed container 1 through the liquid injection port 10, flows into the pressing plate 3, and finally flows along the pressing plate 3 to the surroundings and penetrates into the battery pole piece, so that the battery pole piece reaches a wet state. The vacuum extraction device of this embodiment can use a vacuum pump.

[0030] In one embodiment, the sensing and measuring unit 12 includes a displacement sensor, which is arranged on the upper wall of the sealed container 1, and the displacement sensor is connected to the smart mobile terminal in communication. That is, it can be understood that as the soaking time of the battery pole piece 2 increases, the thickness of the battery pole piece 2 changes, and acts on the pressing plate 3, driving the pressing plate 3 to produce displacement in the thickness direction, so that the displacement of the pressing plate 3 in the thickness direction of the battery pole piece 2 is measured by the displacement sensor, and the displacement sensor feeds back its own measurement data to the smart mobile terminal, and the smart mobile terminal displays the measurement data of the displacement sensor in real time, so that the swelling thickness of the battery pole piece 2 can be understood in real time, and the change trend of the pole piece thickness over time can be monitored throughout the process.

[0031] Of course, in other embodiments, the displacement sensor can also be electrically connected to the display, and the display will display the data of the thickness change of the pressure plate 3 measured by the displacement sensor, and the swelling thickness of the battery electrode 2 can also be understood in real time, and the changing trend of the electrode thickness over time can be monitored throughout the process.

[0032] It should be noted that the intelligent mobile terminal can be a computer, a smart phone, a tablet computer, etc., and is not limited here.

[0033] In one embodiment, the injection port 10 is provided above the pressing plate 3, and the lower surface of the pressing plate 3 is a plane that fits the upper surface of the battery pole piece 2; wherein, a drainage portion is provided on the upper surface of the pressing plate 3, and the drainage is used to drain the electrolyte to the battery pole piece. That is, it can be understood that after the electrolyte is injected into the sealed container 1 through the injection port 10, it flows into the pressing plate 3, and then, under the drainage effect of the drainage portion on the pressing plate 3, it penetrates into the battery pole piece, so that the battery pole piece reaches a wet state, which can facilitate the electrolyte to wet the battery pole piece and achieve the effect of quickly wetting the battery pole piece.

[0034] In one embodiment, the pressing plate 3 is in the shape of a quadrangular pyramid, and the slope surface 30 of the quadrangular pyramid forms the drainage portion mentioned above. In this way, after the electrolyte enters the sealed container 1 from the injection port 10, it is drained to the battery pole piece 2 through the slope surface 30 of the pressing plate 3 in the shape of a quadrangular pyramid, so that the battery pole piece 2 reaches a wet state. It can be seen that designing the pressing plate 3 as a quadrangular pyramid helps the electrolyte to penetrate into the battery pole piece 2, so that the battery pole piece 2 achieves an infiltration effect. Of course, different slopes can also be designed to allow the electrolyte to flow into the interior of the pole piece, which helps the electrolyte to penetrate into the interior of the pole piece.

[0035] In one embodiment, since the pressing plate 3 is in the shape of a quadrangular pyramid, in order to make the measurement result of the displacement sensor more accurate, it will not be affected by the slope of the pressing plate 3. In this embodiment, at least one slope surface 30 of the pressing plate 3 is provided with a boss 31, and the upper surface of the boss 31 is parallel to the battery electrode 2, so as to ensure that the thickness of the battery electrode 2 measured by the displacement sensor will not be affected by the slope of the pressing plate 3.

[0036] In one embodiment, the boss 31 is slidably disposed on the slope surface 30 of the pressing plate 3 along the inclination direction of the slope surface 30 of the pressing plate 3, and the displacement sensor is movably disposed on the sealed container 1. For example, when the position of the boss 31 slides to the A position, the displacement sensor movably disposed on the sealed container 1 can be moved to the corresponding A position; when the position of the boss 31 slides to the B position, the displacement sensor movably disposed on the sealed container 1 can be moved to the corresponding B position, so that the displacement sensor can change with the position change of the boss 31. For example, before the pressing plate 3 is placed into the sealed container 1, the position of the boss 31 at this time can be known, and then the displacement sensor can be moved to the corresponding position of the boss 31. In this way, the displacement sensor can always measure the change of the boss 31 on the upper surface of the pressing plate 3 in the direction of the thickness of the electrode plate in real time, thereby obtaining the swelling thickness of the electrode plate. After the electrode plate is immersed in the electrolyte, the electrode plate absorbs the electrolyte, causing the thickness of the electrode plate to change. After the thickness of the electrode plate changes, the displacement change in the vertical direction of the upper pressing plate is pushed, that is, the thickness change of the electrode plate. It can be seen that through the above-mentioned sliding of the boss 31 and the active setting of the displacement sensor, the thickness change trend of different positions of the battery pole piece 2 can be measured, which is conducive to the study of the thickness data analysis of the battery pole piece 2. In one embodiment, the displacement sensor can be slidably set on the sealed container 1. Of course, the sliding direction of the displacement sensor is parallel to the battery pole piece 2, and the sliding direction of the displacement sensor is the same as the sliding direction of the boss 31, so that it can be ensured that the displacement sensor can always measure the change of the boss 31 on the upper surface of the pressing plate 3 in the direction of the electrode pole piece thickness in real time. The sliding direction of the displacement sensor is set parallel to the battery pole piece 2 in order to better measure the displacement change in the vertical direction of the boss caused by the thickness of the pole piece.

[0037] Of course, in other embodiments, the displacement sensor can also be fixed on the upper wall of the sealed container 1 by pasting. When the position of the boss 31 changes, the displacement sensor can be removed and pasted on the upper wall of the sealed container 1, and the displacement sensor corresponds to the position of the boss 31 in the thickness direction of the pole piece. Therefore, the way in which the displacement sensor is movably arranged on the sealed container 1 is not limited.

[0038] In one embodiment, at least two opposite slope surfaces 30 of the quadrangular pyramid are provided with bosses 31, the two bosses 31 are symmetrical about the center point of the pressing plate 3, a plurality of displacement sensors are provided, the plurality of displacement sensors are arranged at intervals in the horizontal direction, and the plurality of bosses 31 correspond to the plurality of displacement sensors one by one. That is, it can be understood that by measuring the thickness change of two positions symmetrical about the center point of the pressing plate 3, and then taking the average value of the thickness of the two positions, the swelling thickness of the battery electrode 2 can be measured more accurately.

[0039] Of course, in other embodiments, the swelling thickness of the battery electrode 2 can also be measured by measuring the thickness change at two positions on the pressing plate 3 that are not symmetrical about the center point thereof and then taking the average value of the thickness at the two positions.

[0040] In one embodiment, a slot 32 is provided on the slope surface 30, and the boss 31 is slidably connected to the slot 32, that is, the boss 31 is slidably connected to the slope surface 30 of the pressure plate 3 through the slot 32, and the boss 31 can be slidably connected to the slot 32 through a slider, so that the boss 31 can slide along the inclined direction of the slope surface 30 of the pressure plate 3, and the thickness change trend of different positions of the battery electrode 2 can be measured; at the same time, part of the boss 31 is located in the slot 32, and the height of the pressure plate 3 can also be reduced, which can save the space occupied by the sealed container 1 to a certain extent.

[0041] In addition, it should be noted that different pressure values ​​can be applied to the battery pole piece 2 by controlling the thickness change of the pressure plate 3, and the changing trend of the pole piece thickness under different pressure conditions can be studied, which provides certain data support for studying the pole piece thickness and battery cell thickness issues. The thickness change of the pressure plate 3 can be achieved by replacing different pressure plates 3.

[0042] Among them, the above-mentioned pole piece thickness change rate is also the pole piece rebound rate; position 1 refers to the first position for installing the displacement sensor, position 2 refers to the second position for installing the displacement sensor, and the displacement sensors at position 1 and position 2 correspond to the bosses 31 on the opposite sides of the upper surface of the pressure plate 3 respectively.

[0043] The following is an example of measuring the thickness of the battery pole piece 2 over time.

[0044] Embodiment 1:

[0045] Take a positive electrode sheet 4 with a size of 410mm long and 190mm wide, lay it flat in the sealed container 1, place the pressing plate 3 on the upper surface of the positive electrode sheet 4, and then cover the cover of the sealed container 1 to achieve a sealing effect; the size of the pressing plate 3 is 415mm long, 195mm wide and 5mm high, the boss 31 is 1mm higher than the upper surface of the pressing plate 3, and the weight of the entire pressing plate 3 is 1kg. The surface pressure P applied to the positive electrode sheet 4 = 1kg*9.8(N / kg) / (410*190)mm 2 =125.8N / m 2 (Formula P = m*g / S). A vacuum pump is used to make the internal environment reach -90kpa through the exhaust port 11, and then the injection port 10 is opened to inject the electrolyte into the sealed container 1 through the conduit. The injected electrolyte infiltrates into the battery electrode 2 through the pressing plate 3. The displacement sensor collects the height change of the boss 31 on the pressing plate 3 to record the time t0 starting at this time and the heights h1,0 and h2,0 of position 1 and position 2 and records them in Table 1. h1,0 represents the height of position 1 at time t0, h2,0 represents the height of position 2 at time t0, and so on; as the infiltration time of the positive electrode sheet 4 increases, the thickness of the positive electrode sheet 4 changes continuously, generating a force to push the pressing plate 3 to produce a displacement in the thickness direction. The displacement sensor measures the height changes of the boss 31 of the pressing plate 3 at positions 1 and 2 in real time, and transmits the data to the smart mobile terminal for real-time recording in Table 1. The thickness of the positive electrode sheet 4 at position 1 and position 2 is calculated to be d1,x=h1,x-5-1 and d2,x=h2,x-5-1. d1,x represents the thickness of the electrode sheet at position 1 at a certain moment, and d2,x represents the thickness of the electrode sheet at position 2 at a certain moment. The rebound of the positive electrode sheet 4 is calculated by the change of the thickness of the positive electrode sheet 4 at different times, λ1,x=(d1,x-d1,0) / d1,0 and λ2,x=(d2,x-d2,0) / d2,0. The rebound λ1,x represents the rebound rate of the electrode sheet at position 1 at a certain moment, and the rebound λ2,x represents the rebound rate of the electrode sheet at position 2 at a certain moment. The rebound data corresponding to different times are recorded in Table 1. Table 1: Changes of the thickness of the positive electrode sheet 4 over time and the rebound rate data of the positive electrode sheet 4

[0046]

[0047] Embodiment 2:

[0048] Take a negative electrode sheet 42 with a size of 413mm long and 193mm wide, lay it flat in the sealed container 1, place the pressing plate 3 on the upper surface of the negative electrode sheet 42, and then cover the cover of the sealed container 1 to achieve a sealing effect. The size of the pressing plate 3 is 415mm long, 195mm wide and 5mm high. The boss 31 is 1mm higher than the upper surface of the upper pressing plate 3. The weight of the entire upper pressing plate 3 is 1kg. The surface pressure P applied to the negative electrode sheet 42 = 1kg*9.8 (N / kg) / (413*193)mm 2 =123N / m 2 (Formula P = m*g / S). A vacuum pump is used to make the internal environment reach -90kpa through the exhaust port 11, and then the injection port 10 is opened to inject the electrolyte into the sealed container 1 through the conduit. The injected electrolyte infiltrates into the negative electrode sheet 42 through the slope surface 30 of the pressing plate 3. The displacement sensor records the starting time t0 and the heights h1,0 and h2,0 of position 1 and position 2 by collecting the height changes of the boss 31 of the pressing plate 3 and records them in Table 1. h1,0 represents the height of position 1 at time t0, h2,0 represents the height of position 2 at time t0, and so on; as the infiltration time of the negative electrode sheet 42 increases, the thickness of the negative electrode sheet 42 changes continuously, generating a force to push the pressing plate 3 to produce displacement in the thickness direction. The displacement sensor measures the height changes of the boss 31 of the pressing plate 3 at positions 1 and 2 in real time, and transmits the data to the computer for real-time recording in Table 2. The thickness of the pole piece at position 1 and position 2 is calculated to be d1,x=h1,x-5-1; d2,x=h2,x-5-1, d1,x represents the thickness of the pole piece at position 1 at a certain moment, d2,x represents the thickness of the pole piece at position 2 at a certain moment, and the rebound of the negative pole piece 42 is calculated by the thickness change of the negative pole piece 42 at different times λ1,x=(d1,x-d1,0) / d1,0, λ2,x=(d2,x-d2,0) / d2,0, the rebound λ1,x represents the rebound rate of the pole piece at position 1 at a certain moment, and the rebound λ2,x represents the rebound rate of the pole piece at position 2 at a certain moment, and the rebound data corresponding to different times are recorded in Table 2.

[0049] Table 2: Changes in thickness of negative electrode sheet 42 over time and electrode rebound rate data

[0050]

[0051] Embodiment 3:

[0052] Take a negative electrode sheet 42 with a size of 413 mm long and 193 mm wide, a separator 41 with a size of 413 mm long and 193 mm wide, and a positive electrode sheet 4 with a size of 410 mm long and 190 mm wide, and stack them in a sealed container 1 in order to form a single-chip battery structure of negative electrode sheet 42-separator 41-positive electrode sheet 4, as shown in FIG. Figure 4 As shown, the pressure plate 3 is placed on the upper surface of the single-chip battery, and then the cover of the sealed container 1 is covered to achieve a sealing effect. The size of the pressure plate 3 is 415mm long * 195mm wide * 5mm high, the boss 31 is 1mm higher than the upper surface of the upper pressure plate 3, and the weight of the entire upper pressure plate 3 is 1kg. The surface pressure P applied to the single-chip battery = 1kg * 9.8 (N / kg) / (413 * 193) mm 2 =123N / m 2 (Formula P = m*g / S). A vacuum pump is used to make the internal environment reach -90kpa through the exhaust port 11, and then the injection port 10 is opened to inject the electrolyte into the sealed container 1 through the conduit. The injected electrolyte infiltrates into the single-chip battery through the slope surface 30 of the pressing plate 3. The displacement sensor collects the height change of the boss 31 of the pressing plate 3 to record the time t0 starting at this time and the heights h1,0 and h2,0 of position 1, position 2, and records them in Table 3. h1,0 represents the height of position 1 at the moment t0, h2,0 represents the height of position 2 at the moment t0, and so on; as the electrode sheet infiltration time increases, the thickness of the single-chip battery changes continuously, generating a force to push the pressing plate 3 to produce displacement in the thickness direction. The displacement sensor measures the height changes of the boss 31 of the pressing plate 3 at the position 1 and position 2 in real time, and transmits the data to the computer for real-time recording in Table 3. The thickness of the pole pieces at position 1 and position 2 is calculated to be d1,x=h1,x-5-1 and d2,x=h2,x-5-1. d1,x represents the thickness of the pole piece at position 1 at a certain moment, and d2,x represents the thickness of the pole piece at position 2 at a certain moment. The pole piece rebound λ1,x=(d1,x-d1,0) / d1,0 and λ2,x=(d2,x-d2,0) / d2,0 are calculated by changing the thickness of the single piece at different times. The rebound λ1,x represents the rebound rate of the pole piece at position 1 at a certain moment, and the rebound λ2,x represents the rebound rate of the pole piece at position 2 at a certain moment. The rebound data corresponding to different times are recorded in Table 3.

[0053] Table 3: Changes in thickness of a single cell over time and overall rebound rate data

[0054]

[0055] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A battery electrode thickness testing device, characterized in that: It includes a sealed container and a pressing plate, wherein the sealed container is used to place the battery pole piece, the pressing plate is used to be placed on the upper surface of the battery pole piece, the sealed container is provided with a liquid injection port for injecting electrolyte into the sealed container, and the sealed container is also provided with an inductive measuring unit, and the inductive measuring unit is used to detect the displacement change of the pressing plate in the thickness direction of the battery pole piece.

2. The battery electrode thickness testing device according to claim 1, characterized in that: The sealed container is also provided with an air extraction port, and the air extraction port is used to be connected to a vacuum extraction device outside the sealed container.

3. The battery electrode thickness testing device according to claim 1, characterized in that: The inductive measuring unit comprises a displacement sensor, and the displacement sensor is arranged on the upper wall in the sealed container.

4. The battery electrode thickness testing device according to claim 1, characterized in that: The liquid injection port is arranged above the pressing plate, the lower surface of the pressing plate is a plane that fits the upper surface of the battery electrode, and a drainage portion is provided on the upper surface of the pressing plate, and the drainage portion is used to drain the electrolyte to the battery electrode.

5. The battery electrode thickness testing device according to claim 4, characterized in that: The inductive measurement unit includes a displacement sensor, which is arranged on the upper wall of the sealed container. A boss is provided on the drainage portion, and the upper surface of the boss is parallel to the battery electrode. The displacement sensor is used to measure the displacement change of the boss in the thickness direction of the battery electrode.

6. The battery electrode thickness testing device according to claim 5, characterized in that: The pressing plate is in the shape of a quadrangular pyramid, and the slope surface of the quadrangular pyramid forms the drainage portion.

7. The battery electrode thickness testing device according to claim 6, characterized in that: The boss is slidably arranged on the pressure plate along the inclination direction of the slope surface of the quadrangular pyramid, and the displacement sensor is movably arranged on the sealed container so that the displacement sensor can change with the position of the boss.

8. The battery electrode thickness testing device according to claim 7, characterized in that: The displacement sensor can be slidably arranged on the sealed container, and the sliding direction of the displacement sensor is parallel to the battery pole piece.

9. The battery electrode thickness testing device according to claim 8, characterized in that: At least two opposite slope surfaces of the quadrangular pyramid are provided with bosses, and a plurality of displacement sensors are provided, and the plurality of bosses correspond one to one with the plurality of displacement sensors; the two bosses are symmetrical about the center point of the pressure plate.

10. The battery electrode thickness testing device according to claim 6, characterized in that: A slot is provided on the slope surface of the quadrangular pyramid, and the boss is slidably connected to the slot.

Images