Electrolyte wettability testing device

Abstract

The utility model provides an electrolyte wettability testing device. The electrolyte wettability testing device comprises a base, a balance bracket, an electrolyte reaction container and a weighing assembly, the middle of the balance support is connected with the base, a first connecting cable is arranged at the first end of the balance support and used for being connected with a test sample, the second end of the balance support is connected with the weighing assembly, and electrolyte is arranged in the electrolyte reaction container. The distance between one end, far away from the balance bracket, of the first connecting cable and the liquid level of the electrolyte is smaller than the height of the test sample. A test sample is immersed in an electrolyte, the electrolyte infiltrates the test sample, a weighing assembly is used for measuring the weight change of the test sample, then the wettability of the electrolyte on the test sample can be quantitatively represented according to the weight change of the test sample, the liquid injection amount of the electrolyte is further determined, and a proper amount of the electrolyte is injected. And the production cost is not increased while the battery performance is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of battery detection, in particular to an electrolyte wettability testing device. Background Art

[0002] Lithium battery is a secondary battery with the advantages of high energy, high density and high safety. It has become one of the main directions in the field of new energy. Lithium batteries generally include four parts: positive / negative electrode plates, diaphragms, electrolytes and shells. With the market's pursuit of high energy and high density, the problem of electrolyte wetting has gradually become a problem. The good / bad electrolyte wettability of the battery affects the cycle performance and safety performance of the battery cell. When the battery wettability is poor, the lithium ion transmission path becomes longer, which affects the shuttling of lithium ions between the positive / negative electrodes, and then leads to insufficient wetting of the electrode plates, which cannot participate in the battery's electrochemical reaction, resulting in poor battery cell performance. The electrolyte wettability is the main influencing factor of the battery injection volume. Excessive injection volume will also cause the energy density of the battery cell to deteriorate, while also wasting resources and increasing battery costs.

[0003] The usual means of detecting the wettability of the electrolyte are traditional in-situ observation, ultrasonic technology or CT technology; but whether it is traditional in-situ observation, ultrasonic technology or CT technology, these detection technologies usually require high-precision equipment and instruments, such as high-resolution microscopes, ultrasonic scanning equipment or CT scanners, which leads to high costs for detecting the wettability of the electrolyte. Utility Model Content

[0004] Based on this, it is necessary to provide an electrolyte wettability testing device to address the above technical issues.

[0005] An electrolyte wettability testing device, comprising:

[0006] Base, balance bracket, electrolyte reaction vessel and weighing assembly;

[0007] The middle part of the balance bracket is connected to the base, the first end of the balance bracket is provided with a first connecting rope, the first connecting rope is used to connect the test sample, the second end of the balance bracket is connected to the weighing component, the electrolyte reaction container is provided with electrolyte, and the distance between the end of the first connecting rope away from the balance bracket and the liquid level of the electrolyte is less than the height of the test sample.

[0008] In one embodiment, the electrolyte reaction container is provided with scale markings.

[0009] In one embodiment, the electrolyte reaction container includes a container body and a cover plate, the electrolyte is arranged in the container body, the container body has a delivery port, and the cover plate movably closes the delivery port; the cover plate is provided with a through hole, and one end of the first connecting rope away from the balance bracket passes through the through hole and is at least partially located in the container body.

[0010] In one embodiment, the weighing assembly includes a weight and a weighing pan, the weighing pan is connected to the second end of the balancing bracket via a second connecting cable, and the weighing pan is used to hold the weight.

[0011] In one embodiment, a first clamp and a second clamp are provided on the balancing bracket, one end of the first connecting cable is clamped on the first end of the balancing bracket through the first clamp, and one end of the second connecting cable is clamped on the second end of the balancing bracket through the second clamp.

[0012] In one embodiment, a movable fixed partition is further provided in the electrolyte reaction container, and the fixed partition is used to fix the test sample.

[0013] In one embodiment, the first connecting cable and the second connecting cable are both inelastic connecting ropes.

[0014] In one embodiment, the base includes a support column and a support block, the support column is arranged on the support block, and the support column is rotatably connected to the middle part of the balance bracket.

[0015] In one embodiment, a third clamp is provided at one end of the first connecting cable away from the balancing support, and the first connecting cable is used to clamp the test sample.

[0016] In one embodiment, the weighing assembly further includes an electronic balance, and the weighing pan is placed on the electronic balance.

[0017] The above-mentioned electrolyte wettability testing device immerses the test sample in the electrolyte so that the electrolyte wets the test sample, uses a weighing component to measure the weight change of the test sample, and then determines the wettability of the electrolyte on the test sample based on the weight change of the test sample, and further determines the injection amount of the electrolyte, so that the electrolyte is injected in an appropriate amount to ensure battery performance without increasing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of an electrolyte wettability testing device in one embodiment;

[0019] Figure 2 It is a schematic diagram of the amount of liquid absorbed by an electrode of the same mass in different electrolytes in one embodiment.

[0020] Figure numerals: 1. base; 11. support column; 12. support block; 2. balance bracket; 21. first clamp; 22. second clamp; 3. electrolyte reaction container; 31. container body; 32. cover plate; 33. through hole; 4. weighing assembly; 41. weight; 42. weighing pan; 43. electronic balance; 5. first connecting rope; 51. third clamp; 6. fixed partition. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] Embodiment 1

[0023] In this embodiment, Figure 1 As shown, an electrolyte wettability testing device is provided, comprising a base 1, a balance bracket 2, an electrolyte reaction container 3 and a weighing component 4;

[0024] The middle part of the balance bracket 2 is connected to the base 1, and a first connecting rope 5 is provided at the first end of the balance bracket 2, and the first connecting rope 5 is used to connect the test sample. The second end of the balance bracket 2 is connected to the weighing component 4, and the electrolyte reaction container 3 is provided with electrolyte. The distance between the end of the first connecting rope 5 away from the balance bracket 2 and the liquid level of the electrolyte is less than the height of the test sample.

[0025] In this embodiment, the test sample may be a positive / negative electrode sheet, a separator, or a battery cell; no specific limitation is made here.

[0026] Specifically, the middle part of the balance bracket 2 is connected to the base 1, and the balance bracket 2 has a first end and a second end arranged oppositely; the first end of the balance bracket 2 is provided with a first connecting rope 5, and the first connecting rope 5 is used to connect the test sample; the second section of the balance bracket 2 is connected to the weighing component 4. The electrolyte reaction container 3 is placed below the first end of the balance bracket 2; and the electrolyte reaction container 3 is provided with electrolyte; the distance between the end of the first connecting rope 5 away from the balance bracket 2 and the liquid surface of the electrolyte is less than the height or thickness of the test sample, so that the test sample can be immersed in the electrolyte, so that the electrolyte infiltrates the test sample. After the electrolyte infiltrates the test sample, the test sample absorbs the electrolyte, so that the weight of the test sample changes, and the weight change of the test sample is measured using the weighing component 4. The weight change of the test sample is the amount of electrolyte absorbed by the test sample, which can quantitatively characterize the wettability of the electrolyte on the test sample.

[0027] For example, before immersing the test sample in the electrolyte, the initial weight of the test sample is measured by the measuring assembly and recorded as: m 0 When the test sample is immersed in the electrolyte, the weight change of the test sample is measured by the weighing component 4, and the weight change of the test sample is recorded in sequence as follows: m 1 、m 2 、m 3 、m 4 、m 5 、m 6 ,...,m x-1 、m x , when m x -m x-1 When the value of tends to 0, stop recording and calculate m x -m 1 , that is, m x -m 0 The value is the amount of electrolyte absorbed by the test sample.

[0028] In this embodiment, when the test sample is immersed in the electrolyte in the container body 31, the test sample is subject to relative buoyancy. Therefore, when calculating the amount of electrolyte absorbed by the test sample through weights, it is necessary to consider eliminating the influence of buoyancy. The buoyancy of the test sample in the electrolyte depends on factors such as the volume of the sample and the density of the electrolyte. In one embodiment of the present invention, when the buoyancy of the test sample is within a preset no-effect range, the influence of the buoyancy on the test sample can be ignored. In this embodiment, since the volume of the test sample is small, the buoyancy it is subject to is small and therefore can be ignored.

[0029] In this embodiment, the test sample is immersed in the electrolyte so that the electrolyte infiltrates the test sample, and the weight change of the test sample is measured using the weighing component 4, and then the wettability of the electrolyte on the test sample can be quantitatively characterized according to the weight change of the test sample, and the injection amount of the electrolyte is further determined, so that the electrolyte is injected in an appropriate amount to ensure the battery performance without increasing the production cost. In this embodiment, the balance bar principle is used to measure the amount of electrolyte absorbed by the test sample, and the weight change of the test sample can be obtained more intuitively; and the balance bracket 2 based on the balance bar principle does not rely on electronic components, so it is less sensitive to environmental factors, making it easier to measure the amount of liquid absorbed by the test sample.

[0030] In one embodiment, at least 1 / 4 of the test sample is immersed in the electrolyte.

[0031] In one embodiment, the test sample is vertically suspended from the first connecting cable 5 .

[0032] In this embodiment, when the test sample is a positive / negative electrode sheet, the positive / negative electrode sheet is immersed in an electrolyte, and the measurement result of the weighing component 4 is the amount of electrolyte absorbed by the positive / negative electrode sheet; when the test sample is a diaphragm, the measurement result of the weighing component 4 is the amount of electrolyte absorbed by the diaphragm; when the test sample is a battery cell, the measurement result of the weighing component 4 is the amount of electrolyte absorbed by the battery cell.

[0033] In one embodiment, the electrolyte reaction container 3 is provided with a scale mark. In one embodiment, a scale is provided in the electrolyte reaction container, and a scale mark is provided on the scale; in one embodiment, a scale mark is provided on the side wall of the electrolyte reaction container, and the side wall of the electrolyte reaction container is set to be transparent. In one embodiment, the side wall of the electrolyte reaction container is transparent glass or transparent acrylic.

[0034] In this embodiment, the electrolyte reaction container 3 is provided with a scale mark. In order to facilitate observation of the height of the electrolyte climbing when the test sample is in the electrolyte, the electrolyte reaction container 3 can be set as a transparent body. For example, a preset interval time for observing the height is set. When the test sample is immersed in the electrolyte for wettability detection, the initial height of the electrolyte climbing is set as the initial state, recorded as h 0 , and record the current time T. When it reaches nT, the climbing height is recorded, where n is a positive integer and n≥1. For example, h 1 、h 2 、h 3 ,...,h t ,According to the change of the wetting height of the test sample, the wetting efficiency and quality of the electrolyte on the sample can be qualitatively characterized.

[0035] In one embodiment, the initial state is 0.

[0036] In this embodiment, the preset interval time of observing the height can be set to 1 minute, can also be set to 30 seconds, and can also be set to any specific time period; no specific limitation is made here.

[0037] In one embodiment, the electrolyte reaction container 3 includes a container body 31 and a cover plate 32, the electrolyte is arranged in the container body 31, the container body 31 has a loading port, and the cover plate 32 movably closes the loading port; the cover plate 32 is provided with a through hole 33, and the end of the first connecting rope 5 away from the balance bracket 2 passes through the through hole 33 and is at least partially located in the container body 31.

[0038] Specifically, the electrolyte reaction container 3 includes a container body 31 and a cover plate 32. A delivery port is provided above the container body 31, and the electrolyte is delivered into the container body 31 from the delivery port. The cover plate 32 is used to movably close the delivery port. Before the electrolyte is delivered into the container body 31 from the delivery port, the cover plate 32 is removed from the delivery port. When the test sample is immersed in the electrolyte and the electrolyte wettability test is performed, the delivery port is sealed with the cover plate 32. Subsequently, the test sample connected to the first connecting rope is passed through the through hole 33, placed in the container body 31 and immersed in the electrolyte. The end of the first connecting rope 5 away from the balance bracket 2 passes through the through hole 33 on the cover plate 32, and is at least partially located in the container body 31. The end of the first connecting rope 5 in the container body 31 fixes the test sample in the container body 31; and the distance between the end of the first connecting rope 5 away from the balance bracket 2 and the liquid surface of the electrolyte is less than the height of the test sample.

[0039] In this embodiment, since the electrolyte has a certain volatility, the cover plate 32 is used to seal the container body 31, which can reduce the volatilization of the electrolyte and improve the accuracy of the electrolyte wettability detection results; and the electrolyte may also be corrosive or toxic. The cover plate 32 is used to seal the container body 31 to prevent the electrolyte from splashing or leaking, thereby improving the safety of the electrolyte wettability detection.

[0040] In one embodiment, a gap is provided between the first connecting cable 5 and the through hole 33 on the cover plate 32 .

[0041] In one embodiment, the weighing assembly 4 includes a weight 41 and a weighing pan 42 . The weighing pan 42 is connected to the second end of the balancing bracket 2 via a second connecting cable. The weighing pan 42 is used to hold the weight 41 .

[0042] Specifically, the weighing assembly 4 includes a weight 41 and a weighing pan 42, the weighing pan 42 is connected to the second end of the balancing bracket 2 via a second connecting cable; the first end of the balancing bracket 2 is connected to the test sample using a first connecting cable 5; when the weight of the test sample is measured using the weighing assembly 4, a balance bar is formed. In this embodiment, the first end and the second end of the balancing bracket 2 are always kept in balance by removing or adding the weight 41 to the weighing pan 42, and when the first end and the second end of the balancing bracket 2 are in balance, the weight of the weight 41 is the current weight of the test sample.

[0043] In this embodiment, a weight 41 and a weighing pan 42 are used to measure the weight change of the test sample. The weight change of the test sample can be obtained by simply adding or reducing the weight 41 on the weighing pan 42 so that the first end and the second end of the balance bracket 2 are in a balanced state. The weight change of the test sample, that is, the amount of electrolyte absorbed by the test sample, can be measured quickly and easily.

[0044] In one embodiment, the weight 41 is any object marked with a weight mark and is used to measure weight.

[0045] In one embodiment, a first clamp 21 and a second clamp 22 are provided on the balance bracket 2, one end of the first connecting cable 5 is clamped on the first end of the balance bracket 2 through the first clamp 21, and one end of the second connecting cable is clamped on the second end of the balance bracket 2 through the second clamp 22.

[0046] Specifically, the balance bracket 2 is provided with a first clamp 21 and a second clamp 22, wherein the first clamp 21 is arranged at the first end of the balance bracket 2, and the second clamp 22 is arranged at the second end of the balance bracket 2; the first clamp 21 clamps one end of the first connecting cable 5 to the first end of the balance bracket 2; the other end of the first connecting cable 5 passes through the through hole 33 on the cover plate 32 of the electrolyte reaction container 3, at least partially in the container body 31, and fixes the test sample in the container body 31. The second clamp 22 clamps one end of the second connecting cable to the second end of the balance bracket 2, and the other end of the second connecting cable is connected to the weighing pan 42 of the weighing assembly 4.

[0047] In this embodiment, the materials of the first clamp 21 and the second clamp 22 may be the same or different, which is not specifically limited here.

[0048] In this embodiment, the first connecting cable 5 can be more conveniently fixed to the balancing bracket 2 by the first clamp 21, and the position of the first connecting cable 5 can be moved according to actual conditions. Similarly, the second connecting cable can be more conveniently fixed to the balancing bracket 2 by the second clamp 22, and the second connecting cable can also be moved according to actual conditions. By providing the first clamp 21 and the second clamp 22, the first connecting cable and the second connecting cable can be conveniently and quickly fixed, and can also be quickly disassembled, so that the position and extension length of the first connecting cable and the second connecting cable on the balancing bracket 2 can be quickly and conveniently adjusted.

[0049] In one embodiment, a movable fixed partition 6 is further provided in the electrolyte reaction container 3, and the fixed partition 6 is used to fix the test sample.

[0050] Specifically, a movable fixed partition 6 is provided in the electrolyte reaction container 3, that is, the fixed partition 6 can be arranged in the electrolyte reaction container 3 or outside the electrolyte reaction container 3. When the test sample needs to use the fixed partition 6 to fix its shape, the fixed partition 6 is arranged in the electrolyte reaction container 3 to fix and maintain the shape of the test sample. For example, when the test sample has wrinkles and / or a non-vertical shape, the fixed partition 6 is used to flatten the test sample.

[0051] In this embodiment, before the electrolyte wettability test is performed, the test sample is flattened using a fixed partition 6 to prevent the test sample from having wrinkles and / or non-vertical shapes, thereby affecting the measurement results of the electrolyte wettability.

[0052] In one embodiment, the first connecting rope 5 and the second connecting rope are both inelastic connecting ropes.

[0053] In this embodiment, the first connecting rope 5 and the second connecting rope are set as inelastic connecting ropes, which can ensure that the first end and the second end of the balance bracket 2 maintain a stable total platform and position when the electrolyte wettability test is performed; and will not be affected by external forces to cause expansion or deformation, thereby maintaining the geometric accuracy and stability between the first end and the second end of the balance bracket 2.

[0054] In one embodiment, the base 1 includes a support column 11 and a support block 12 , wherein the support column 11 is disposed on the support block 12 , and the support column 11 is connected to the middle portion of the balance bracket 2 .

[0055] Specifically, the base 1 may include a support column 11 and a support block 12, and the support block 12 is placed on a horizontal plane. At this time, the electrolyte reaction container 3 may also be placed on the same horizontal plane as the support block 12. The support column 11 is arranged on the support block 12, and the support block 12 provides a support base point for the support column 11. The support column 11 is connected to the middle part of the balance bracket 2, and the balance bracket 2 can move up and down along the support column 11. In this embodiment, a fourth clamp can be set on the support column 11, and the middle part of the balance bracket 2 is fixed to the support column 11 using the fourth clamp.

[0056] In this embodiment, the support block 12 can be a cube block, a rectangular block, or a trapezoidal block, which is not specifically limited here.

[0057] In this embodiment, the base 1 is configured as a combination structure of a support block 12 and a support column 11, so that the base 1 has greater stability and a higher load-bearing capacity; its adjustability is also higher, making disassembly or installation easier and more adaptable.

[0058] In one embodiment, a third clamp 51 is disposed at one end of the first connecting cable 5 away from the balancing bracket 2 , and the first connecting cable 5 clamps the test sample through the third clamp 51 .

[0059] Specifically, a third clamp 51 is provided at one end of the first connecting rope 5 away from the balancing bracket 2, and the third clamp 51 is used to clamp the test sample and immerse the test sample in the electrolyte; the other end of the first connecting rope 5 (i.e., the end close to the balancing bracket 2) is fixed to the first end of the balancing bracket 2 by the first clamp 21; so that the weighing component 4 under the second end of the balancing bracket 2 can measure the weight of the test sample.

[0060] In this embodiment, by providing the third clamp 51 to fix the test sample, it is possible to make it easier to fix or remove the test sample on the first connecting rope 5 and improve operability.

[0061] In one embodiment, the weighing assembly 4 further includes an electronic balance 43 , and the weighing pan 42 is placed on the electronic balance 43 .

[0062] Specifically, the weighing assembly 4 includes a weight 41 and a weighing pan 42. In this embodiment, the weight 41 is placed on the weighing pan 42. In order to further accurately measure the weight change of the test sample, the weighing pan 42 is placed on an electronic balance 43. The electronic balance 43 is used to measure the weight of the weight 41 in the weighing pan 42. The weight of the weight 41 in the weighing pan 42 is the weight of the current test sample. For example, an electronic scale is used to first measure the weight of the weighing pan 42, and then the total weight of the weighing pan 42 and the weight 41 in the weighing pan 42 is measured. The total weight minus the weight of the weighing pan 42 is the precise weight of the weight 41, that is, the precise weight of the test sample.

[0063] In this embodiment, the electronic balance 43 and the balance support 2 based on the balance bar principle are combined to measure the amount of electrolyte absorbed by the test sample, which can achieve a simpler and more accurate measurement effect.

[0064] Embodiment 2

[0065] In this embodiment, Figure 1 As shown, an electrolyte wettability testing device is provided, comprising: a balance bracket 2, on the first end of which positive and negative electrodes, a diaphragm and a battery cell can be vertically suspended; a weighing assembly 4 is suspended on the second end of the balance bracket 2; the weighing assembly 4 comprises a weighing pan 42 and a weight 41; the weight 41 or other weight material is placed on the weighing pan 42, and the weighing pan 42 is placed on an electronic balance 43 below; a container body 31 of a visualized electrolyte reaction container 3 is made, the container body 31 is correspondingly arranged at the lower left of the balance bracket 2, and the container body 31 is used to contain electrolyte; during the test, it is required that at least 1 / 4 of the sample to be tested is immersed in the electrolyte; the weighing change of the weighing assembly 4 is the weight change of the electrolyte; in addition, the container body 31 of the electrolyte reaction container 3 is marked with scale marks, so that the climbing height of the infiltration of the test sample can be observed.

[0066] The test device and test process for qualitatively and quantitatively evaluating the wettability of electrolyte, specifically:

[0067] Step 1, first build a balance bracket 2, and fix the middle position of the balance bracket 2 on the support column 11 of the base 1. After being fixed, the two ends of the balance bracket 2 can be flexibly moved up and down; the first end of the balance bracket 2 can vertically hang positive and negative electrodes, diaphragms, and battery cells; the second end of the balance bracket 2 hangs a weighing component 4, which includes a weight 41, a weighing pan 42, and an electronic balance 43 placed underneath; select a container body 31 of a visualized electrolyte reaction container 3, and the container body 31 is correspondingly arranged below the first end of the balance bracket 2, and the container body 31 is used to hold the electrolyte, that is, prepare various experimental devices and samples, and the electrolyte.

[0068] Step 2: Flatten the positive electrode sheet and cut it into 3x5cm strips, leaving 1cm of substrate on the end facing the electrolyte;

[0069] Step 3: The first connecting rope 5 clamps the other end of the positive electrode plate through the third clamp 51. The surface of the positive electrode plate should be flattened to prevent the plate from wrinkling and not being vertical, thereby affecting the measurement result.

[0070] Step 4, remove the cover plate 32 on the container body 31 of the electrolyte reaction container 3, pass the end of the first connecting cable 5 away from the balance bracket 2 through the small hole on the cover plate 32, set the positive electrode plate in the container body 31, and cover the cover plate 32; after the end of the first connecting cable 5 close to the balance bracket 2 passes through the small hole, it is fixed in the first clamp 21 on the first end of the balance bar bracket; wherein the first connecting cable 5 and the small hole are not in contact; the second end of the balance bar bracket is connected to the balance bar bracket and the weighing assembly 4 through the second connecting cable, wherein the weighing assembly 4 includes a weight 41, a weighing pan 42 and an electronic balance 43; the weighing pan 42 is placed on the electronic balance 43, and the weight 41 is added to the weighing pan 42, so that the whole device is in a balanced state, the electronic balance 43 is set to zero, and the mass at this time is recorded as m 0 , which is the initial weight of the positive electrode.

[0071] Step 5. Add electrolyte to the container body 31 of the electrolyte reaction container 3 below the first end of the balance bracket 2, so that the electrolyte immerses one quarter of the positive electrode plate; observe the scale mark on the container body 31, record the height of the positive electrode plate in the initial state of immersion, and observe the weight change on the weighing component 4. Record the initial time, and when the immersion time reaches the preset interval time, record the reading of the electronic balance 43 and the corresponding immersion height at that moment. Specifically, record the changes in the reading of the electronic balance 43 according to different times (for example, 0min, 1min, 3min, ..., T min), and record them in sequence as: m 1 、m 2 、m3 、m 4 、m 5 、m 6 ,...,m x-1 、m x , when m x -m x-1 When the value of tends to 0, stop recording and calculate m x -m 1 , that is, m x -m 0 The value is the amount of electrolyte absorbed by the positive electrode. This quantitatively characterizes the wettability of the electrolyte on the sample (positive and negative electrode, separator, battery cell), and also derives the optimal amount of electrolyte, which maintains the battery performance unchanged while saving production costs. Record the wetted height of the positive electrode, that is, observe the change of the wetted height of the positive electrode over time, recorded as: 0, h 1 、h 2 、h 3 ,...,h T , which can qualitatively characterize the wetting efficiency and quality of the electrolyte on the sample.

[0072] For example, take the positive electrode sheets of the same size and divide them into m 1 、m 2 、m 3 , respectively, for wettability tests, where m 1 、m 2 and m 3 The initial electrolyte masses of the three tests were different, and the values ​​on the electronic balance 43 were recorded every 30 seconds. The data on the change in the mass of the electrode pieces is the amount of electrolyte absorption. The data are shown in Table 1 below.

[0073] Table 1 Liquid absorption of positive electrode sheets of the same mass in different electrolytes

[0074]

[0075]

[0076] Refer to Table 1 above and draw a curve of the liquid absorption of the same mass of positive electrode in different electrolytes, such as Figure 2 shown.

[0077] In this embodiment, the test methods for the negative electrode sheet, the separator, and the entire battery cell are the same as the above-mentioned test steps for the positive electrode sheet.

[0078] When the test sample is a negative electrode, take a negative electrode of the same size h 1 、h 2 and h 3The wettability test was carried out in three sections respectively, and the wetting climbing height at different times was observed. The height of the negative electrode piece relative to the scale mark on the container body 31 was recorded every 30 seconds. The data is shown in Table 2 below.

[0079] Table 2 Climbing height of different negative electrode sheets after infiltration

[0080]

[0081] In one embodiment, the test sample may also be three ceramic-based diaphragms of the same size, and wettability tests are performed on each of them, with the value on the electronic balance 43 being recorded every 30 seconds.

[0082] In one embodiment, the test sample may also be a whole cell, and a wetting experiment is performed, and the value on the electronic balance 43 and the climbing height of the wetting scale are recorded every 30 seconds.

[0083] In this embodiment, the change of the reading of the electronic balance 43 is recorded according to different time (for example, 0 min, 1 min, 3 min, ..., T min), and is recorded in sequence as: m 1 、m 2 、m 3 、m 4 、m 5 、m 6 ,...,m x-1 、m x , when m x -m x-1 When the value of tends to 0, stop recording and calculate m x -m 1 , that is, m x -m 0 The value is the amount of electrolyte absorbed by the positive electrode. This quantitatively characterizes the wettability of the electrolyte on the sample (positive and negative electrode, separator, battery cell), and also derives the optimal amount of electrolyte, which maintains the battery performance unchanged while saving production costs. Record the wetted height of the positive electrode, that is, observe the change of the wetted height of the positive electrode over time, recorded as: 0, h 1 、h 2 、h 3 ,...,h T , which can qualitatively characterize the wetting efficiency and quality of the electrolyte on the sample.

[0084] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An electrolyte wettability testing device, characterized in that: include: Base, balance bracket, electrolyte reaction vessel and weighing assembly; The middle part of the balance bracket is connected to the base, the first end of the balance bracket is provided with a first connecting rope, the first connecting rope is used to connect the test sample, the second end of the balance bracket is connected to the weighing component, the electrolyte reaction container is provided with electrolyte, and the distance between the end of the first connecting rope away from the balance bracket and the liquid level of the electrolyte is less than the height of the test sample.

2. The electrolyte wettability testing device according to claim 1, characterized in that: The electrolyte reaction container is provided with scale markings.

3. The electrolyte wettability testing device according to claim 1, characterized in that: The electrolyte reaction container includes a container body and a cover plate, the electrolyte is arranged in the container body, the container body has a delivery port, and the cover plate movably closes the delivery port; the cover plate is provided with a through hole, and an end of the first connecting rope away from the balance bracket passes through the through hole and is at least partially located in the container body.

4. The electrolyte wettability testing device according to claim 1, characterized in that: The weighing assembly comprises a weight and a weighing pan, wherein the weighing pan is connected to the second end of the balancing bracket via a second connecting rope, and the weighing pan is used for holding the weight.

5. The electrolyte wettability testing device according to claim 4, characterized in that: The balancing bracket is provided with a first clamp and a second clamp, one end of the first connecting cable is clamped on the first end of the balancing bracket through the first clamp, and one end of the second connecting cable is clamped on the second end of the balancing bracket through the second clamp.

6. The electrolyte wettability testing device according to any one of claims 1 to 5, characterized in that: The electrolyte reaction container is also provided with a movable fixed partition, and the fixed partition is used to fix the test sample.

7. The electrolyte wettability testing device according to claim 5, characterized in that: The first connecting rope and the second connecting rope are both inelastic connecting ropes.

8. The electrolyte wettability testing device according to any one of claims 1 to 5, characterized in that: The base comprises a support column and a support block, wherein the support column is arranged on the support block, and the support column is rotatably connected to the middle part of the balance bracket.

9. The electrolyte wettability testing device according to claim 5, characterized in that: A third clamp is provided at one end of the first connecting cable away from the balancing bracket, and the first connecting cable is used to clamp the test sample.

10. The electrolyte wettability testing device according to claim 4, characterized in that: The weighing assembly also includes an electronic balance, and the weighing pan is placed on the electronic balance.

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