Diaphragm testing device

Abstract

The utility model provides a diaphragm testing device, which comprises an accommodating groove for accommodating electrolyte; the square frame is used for installing at least one sample and placing the sample in the containing groove, and the at least one sample extends from the top of the side face of the square frame to the bottom of the square frame and is fixed to the top of the opposite side face after bypassing the bottom face of the square frame. According to the diaphragm testing device, diaphragm samples can be vertically fixed for a long time when the diaphragm is tested, and the diaphragm samples can be arranged in parallel to avoid inclination of the samples, so that the same area of each sample immersed in electrolyte can be ensured, multiple samples can be visually compared at the same time, and the observation is more convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion battery diaphragms, and particularly to a testing device for lithium-ion battery diaphragms. Background Art

[0002] In the structure of a lithium-ion battery, the diaphragm is a key component, and the performance of the diaphragm will directly affect the capacity of the battery. The wetting speed is an important characteristic of the lithium-ion battery diaphragm. The wetting speed of the diaphragm refers to the speed at which the electrolyte enters the micropores of the diaphragm, and it is related to characteristics such as the pore diameter, porosity, and tortuosity of the diaphragm surface. Good wettability is conducive to the mutual affinity between the diaphragm and the electrolyte, expanding the contact surface between the diaphragm and the electrolyte, thereby increasing ionic conductivity and improving the charge-discharge performance and capacity of the battery. Poor wettability of the diaphragm will increase the resistance of the diaphragm and the battery, affecting the cycle performance and charge-discharge efficiency of the battery. Generally speaking, the wettability of the diaphragm can be judged by testing the liquid absorption rate and liquid retention rate of the diaphragm.

[0003] Currently, the commonly used method for testing the wettability of the diaphragm is generally to judge the wettability by measuring the contact angle through a contact angle measuring instrument. The smaller the measured contact angle, the better the wettability, and the larger the contact angle, the worse the wettability. However, this method requires high equipment requirements, is expensive, and has high costs. Another common testing method is to visually observe the diffusion degree of the electrolyte on the diaphragm to judge the wettability. The larger the diffusion range in the same time, the better the wettability, and the smaller the diffusion range, the worse the wettability. However, this method has no clear testing standard and is quite time-consuming. Another common testing method is the climbing column visual observation method, which judges the wettability by observing the climbing height of the electrolyte on the diaphragm sample. The higher the climbing height, the better the wettability. However, in the existing climbing column visual observation method, there are problems such as the diaphragm sample being prone to tilting during the measurement process, being unable to ensure that the diaphragm samples are parallel to each other, and being unable to effectively fix the diaphragm samples. Based on the above problems, the utility model proposes a new diaphragm testing device that can conveniently fix the diaphragm samples and ensure that the diaphragm samples are parallel to each other to improve the above problems. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a diaphragm testing device, which is characterized in that it includes: a containing groove for containing an electrolyte; a square frame for installing at least one sample and placing it in the containing groove; at least one of the samples extends from the top of the side surface of the square frame to the bottom of the square frame, and after bypassing the bottom surface of the square frame, it is fixed to the top of the opposite side surface.

[0005] Preferably, the bottom of the square frame has at least one groove, and the sample is placed in the groove.

[0006] Preferably, the interval between the grooves is 0.5 cm, and the width of the groove is 1.5 cm and the depth is 0.5 cm.

[0007] Preferably, the length of the square frame is 15 cm, the height is 10 cm, and the width is 5 cm.

[0008] Preferably, the length of the sample is 25 to 35 cm and the width is 1 to 2 cm.

[0009] Preferably, the top of the side surface of the square frame and the top of the opposite side surface have holders for fixing the sample.

[0010] Preferably, the accommodating groove is made of a transparent material, and the diaphragm testing device further includes a scale, and the scale is arranged outside the accommodating groove.

[0011] Preferably, the side of the square frame and the scale are perpendicular to the bottom surface of the accommodating groove.

[0012] Preferably, the accommodating groove is made of a transparent material, and the diaphragm testing device further includes a scale, and the scale is arranged on the side surface of the square frame and is perpendicular to the bottom surface of the square frame.

[0013] Preferably, the scale and the square frame are of an integrally formed structure.

[0014] The diaphragm testing device proposed by the present utility model can keep the diaphragm sample vertically fixed for a long time and make the diaphragm samples parallel to each other to avoid sample inclination when performing the creeping liquid method to test the wettability of the diaphragm. In this way, it can ensure that the areas of each sample immersed in the electrolyte are the same to guarantee the consistency and comparability of the test results. In addition, this testing device can also realize the simultaneous and intuitive comparison of multiple samples, which is more convenient for observation, and the structure of the overall testing device is simple. Compared with the existing testing device, the construction cost is lower. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the diaphragm testing device in one state of the present utility model.

[0016] Figure 2 It is a schematic diagram of the diaphragm testing device in another state of the present utility model. Detailed Description of the Invention

[0017] The following is a detailed description of the specific embodiments of the present utility model in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present utility model and are not used to limit the present utility model.

[0018] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0019] Please refer to Figure 1 , Figure 1 FIG. is a schematic diagram of a diaphragm testing device in an embodiment of the present utility model. The diaphragm testing device 100 includes a containing groove 1 and a square frame 2. The containing groove 1 is used to contain the electrolyte 11, and the square frame 2 is placed in the containing groove 1. The containing groove 1 has a top cover for closing the containing groove 1. Preferably, the containing groove 1 is made of a transparent material (such as glass).

[0020] In an embodiment of the present utility model, the electrolyte 11 can be a mixed solution of cyclic carbonates (such as ethylene carbonate (EC)) and linear carbonates (such as dimethyl carbonate (DMC) or ethyl methyl carbonate (EMC)), but the present utility model is not limited thereto.

[0021] The square frame 2 is composed of twelve brackets and is a cubic structure. Preferably, the length of the square frame 2 is 15 cm, the height is 10 cm, and the width is 5 cm. In an embodiment of the present utility model, when the square frame 2 is placed in the containing groove 1, the brackets on the side of the square frame 2 are perpendicular to the bottom surface of the containing groove 1, and the brackets on the top and bottom of the square frame 2 are parallel to the bottom surface of the containing groove 1.

[0022] A plurality of diaphragm samples 12 are placed on one side of the square frame 2. One end of the diaphragm sample 12 is fixed to the top of the side of the square frame 2, and the diaphragm sample 12 extends towards the bottom of the square frame 2. After bypassing the bottom surface of the square frame 2, the other end of the diaphragm sample 12 is fixed to the top of the opposite side, and each diaphragm sample remains parallel to each other. When the square frame 2 is placed in the containing groove 1, a part of the diaphragm sample 12 is immersed in the electrolyte 11. Since a plurality of diaphragm samples 12 can be provided on the square frame 2, in actual testing, a plurality of identical diaphragm samples 12 can be provided on the square frame 2 to compare the test results and increase the accuracy of the test.

[0023] In an embodiment of the present utility model, the length of the diaphragm sample 12 is 25 to 35 cm and the width is 1 to 2 cm. Preferably, the length of the diaphragm sample 12 is 30 cm and the width is 1.5 cm.

[0024] Please refer to Figure 2, in another embodiment of the present utility model, the brackets at the bottom of the square frame 2 have a plurality of grooves 22, and the width of the grooves 22 is the same as the width of the diaphragm sample 12. Thus, when the diaphragm sample 12 is disposed in the square frame 2, it can be received in the grooves, ensuring that each diaphragm sample is parallel to each other. Preferably, the interval between the plurality of grooves 22 is 0.5 cm, and the width of each groove 22 is 1.5 cm and the depth is 0.5 cm.

[0025] In one embodiment of the present utility model, the diaphragm sample 12 is disposed and fixed on the square frame 2 in a direction parallel to the side brackets of the square frame 2, so that the diaphragm sample 12 is immersed in the electrolyte 11 in a direction perpendicular to the liquid surface of the electrolyte 11, and when the square frame 2 is placed in the receiving groove 1, the diaphragm sample 12 is perpendicular to the bottom surface of the receiving groove 1. Preferably, the square frame 2 is a hollow structure. Therefore, when the square frame 2 is placed in the receiving groove 1, both sides of the diaphragm sample 12 can contact the electrolyte 11.

[0026] The diaphragm testing device 100 further includes a scale 3. In one embodiment of the present utility model, the scale 3 can be fixed to the outside of the receiving groove 1, and the tester can know the height that the electrolyte 11 climbs on the diaphragm sample 12 by observing the scale on the scale 3. Specifically, the higher the height that the electrolyte 11 crawls on the diaphragm sample 12, the better the wettability of the sample. On the contrary, the lower the crawling height, the worse the wettability of the sample. Preferably, the scale 3 is perpendicular to the bottom surface of the receiving groove 1. In another embodiment of the present utility model, the scale 3 can be fixed to the square frame 2 or integrally formed on the square frame 2, and the present utility model is not limited thereto.

[0027] In one embodiment of the present utility model, the upper side of the side surface of the square frame 2 has a fixator 21 for fixing the diaphragm sample 12 on the square frame 2 to prevent the diaphragm sample 12 from falling off during the test.

[0028] Hereinafter, the steps of testing the diaphragm sample with the diaphragm testing device of the present disclosure will be illustrated by the following embodiments.

[0029] First step, cut the diaphragm to be tested into a diaphragm sample 12 with a length of 30 cm and a width of 1.5 cm, and fix the diaphragm sample 12 on the side surface of the square frame 2 with the fixator 21, and the diaphragm samples 12 are parallel to each other.

[0030] Second step, prepare an electrolyte 11 with EC:EMC:DMC = 1:1:1 and pour it into the receiving groove 1.

[0031] Third step, place the square frame 2 with the diaphragm sample 12 fixed therein into the receiving groove 1.

[0032] Fourth step, cover the top cover of the receiving groove 1.

[0033] In the fifth step, use a ruler 3 to observe and record the heights that the electrolyte 11 climbs on the diaphragm sample 12 after 1 minute, 5 minutes, 10 minutes, and 30 minutes from the start of the test.

[0034] In the sixth step, analyze and compare the recorded results.

[0035] In summary, the diaphragm testing device proposed by the present utility model can keep the diaphragm sample vertically fixed for a long time and the diaphragm samples can be arranged parallel to each other to avoid sample inclination when performing the wicking method to test the wettability of the diaphragm. Thereby, it can ensure that the areas of each sample immersed in the electrolyte are the same to guarantee the consistency and comparability of the test results. In addition, this testing device can also achieve intuitive comparison of multiple samples, which is more convenient for observation, and the overall structure of the testing device is simple. Compared with the existing testing devices, the construction cost is lower.

[0036] The above content related to common general knowledge will not be described in detail, and those skilled in the art can understand it.

[0037] The above are only some specific embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A diaphragm testing device, characterized in that: include: A containing tank for containing electrolyte; A square frame, used to mount at least one sample and placed in the receiving tank; At least one of the samples extends from the top of the side surface of the square frame to the bottom of the square frame, and after passing around the bottom surface of the square frame, is fixed to the top of the opposite side surface.

2. The diaphragm testing device according to claim 1, characterized in that: The bottom of the square frame has at least one groove, and the sample is accommodated in the groove.

3. The diaphragm testing device according to claim 2, characterized in that: The interval between the grooves is 0.5 cm, and the width of the grooves is 1.5 cm and the depth is 0.5 cm.

4. The diaphragm testing device according to claim 1, characterized in that: The square frame has a length of 15 cm, a height of 10 cm and a width of 5 cm.

5. The diaphragm testing device according to claim 1, characterized in that: The sample has a length of 25 to 35 cm and a width of 1 to 2 cm.

6. The diaphragm testing device according to claim 1, characterized in that: The top of the side surface and the top of the opposite side surface of the square frame have fixers for fixing the sample.

7. The diaphragm testing device according to claim 1, characterized in that: The containing groove is made of a transparent material, and the diaphragm testing device further comprises a scale, and the scale is arranged outside the containing groove.

8. The diaphragm testing device according to claim 7, characterized in that: The side edges of the square frame and the scale are perpendicular to the bottom surface of the accommodating groove.

9. The diaphragm testing device according to claim 1, characterized in that: The containing groove is made of a transparent material, and the diaphragm testing device further comprises a scale, which is arranged on the side surface of the square frame and is perpendicular to the bottom surface of the square frame.

10. The diaphragm testing device according to claim 9, characterized in that: The scale and the square frame are an integrally formed structure.

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