CN112461713A - Device and method for testing wettability of lithium ion battery diaphragm - Google Patents
Device and method for testing wettability of lithium ion battery diaphragm Download PDFInfo
- Publication number
- CN112461713A CN112461713A CN201910839803.9A CN201910839803A CN112461713A CN 112461713 A CN112461713 A CN 112461713A CN 201910839803 A CN201910839803 A CN 201910839803A CN 112461713 A CN112461713 A CN 112461713A
- Authority
- CN
- China
- Prior art keywords
- diaphragm
- electrolyte
- wettability
- lithium ion
- testing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 34
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims abstract description 22
- 230000000007 visual effect Effects 0.000 claims abstract description 9
- 239000012528 membrane Substances 0.000 claims abstract description 8
- 239000003792 electrolyte Substances 0.000 claims description 75
- 238000009792 diffusion process Methods 0.000 claims description 28
- 230000037303 wrinkles Effects 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 abstract description 4
- 239000007788 liquid Substances 0.000 description 6
- 238000010998 test method Methods 0.000 description 3
- 238000005034 decoration Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
- G01N2013/003—Diffusion; diffusivity between liquids
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Secondary Cells (AREA)
Abstract
The invention relates to a device and a method for testing the wettability of a lithium ion battery diaphragm, which are characterized by comprising a diaphragm fixing frame, a diaphragm sample to be tested, a magnifying lens and an image display analysis system; the membrane sample to be detected is fixed on the membrane fixing frame and arranged under the visual field of the magnifier, the magnifier is connected with the image display analysis system, and the image amplified by the magnifier is displayed and analyzed on the image display analysis system. The testing device and the testing method for the wettability of the lithium ion battery diaphragm have the advantages of being simple and easy to obtain testing equipment, short in testing time, simple in calculation and convenient to operate.
Description
Technical Field
The invention relates to the technical field of membrane wettability testing, in particular to a device and a method for testing the wettability of a lithium ion battery membrane.
Background
The lithium ion battery mainly comprises a positive plate, a negative plate, a diaphragm and electrolyte, wherein the diaphragm is one of key materials of the lithium ion battery. Due to the difference of preparation methods, the diaphragm is divided into a wet diaphragm and a dry diaphragm, when the diaphragm is soaked in electrolyte, the good wettability of the diaphragm and the electrolyte is beneficial to improving the permeability of the diaphragm and the electrolyte, and thus the ionic conductivity is increased. Meanwhile, the contact surface between the diaphragm and the electrolyte can be enlarged, the adhesion between the diaphragm and an electrode material is improved, and the resistance between the diaphragm and the battery is reduced, so that the cycle performance and the charge-discharge efficiency of the battery are influenced.
Currently, the wettability of the diaphragm is mainly measured by a visual method and a contact angle meter. And (3) an eye test method, namely, a microinjector is used for absorbing the electrolyte, the electrolyte is dripped on the diaphragm to be tested and timing is started, the timing is stopped after the diaphragm is completely soaked by the electrolyte, the wettability of the diaphragm is judged according to the soaking time difference, the eye test method has no test standard and consumes long time. The contact angle measuring method of the contact angle instrument is characterized in that electrolyte is dripped on a diaphragm to be measured, the distance and the height of two ends of a liquid drop are measured, the contact angle is calculated according to a certain calculation method, the smaller the contact angle value is, the better the lyophilic capability and the better the wettability of the diaphragm are shown, or the wettability is calculated by capturing a dynamic image of the liquid drop spread on the surface of the diaphragm, and the wettability of the electrolyte on the diaphragm can be quantitatively calculated by the contact angle instrument.
In view of this, it is necessary to provide a device and a method for testing wettability of a lithium ion battery separator, so as to solve the disadvantages of long wettability testing time, high requirement on testing equipment, complex calculation and long time consumption at present.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a device and a method for testing the wettability of a lithium ion battery diaphragm.
The process that the electrolyte soaks the diaphragm is also the process that the electrolyte diffuses along the MD and TD directions of the diaphragm, no matter a wet diaphragm or a dry diaphragm, the microstructure of the diaphragm has certain orientation, the orientation degrees in the MD and TD directions are different, the soaking rate is also different when the electrolyte soaks, namely, the diffusion distances of electrolyte drops with the same volume along the same direction of the diaphragm in a certain time are different, and the diffusion distance is far, so that the wettability of the electrolyte to the diaphragm is good, the diffusion distance is small, and the wettability of the electrolyte to the diaphragm is poor.
The purpose of the invention is realized by the following technical scheme:
a testing device for wettability of a lithium ion battery diaphragm comprises a diaphragm fixing frame, a diaphragm sample to be tested, a magnifying lens and an image display analysis system; the membrane sample to be detected is fixed on the membrane fixing frame and arranged under the visual field of the magnifier, the magnifier is connected with the image display analysis system, and the image amplified by the magnifier is displayed and analyzed on the image display analysis system.
The diaphragm mount include 3 support pieces, be "H" shape, 2 wherein support pieces are parallel to each other, 1 support piece direction is perpendicular in addition, the edge stack of its vertical direction support piece is in 2 support piece belows in addition.
A test method for wettability of a lithium ion battery diaphragm comprises the following specific steps:
Further, the diaphragm sample in the step 1 is fixed on a diaphragm fixing frame, the surface of the diaphragm is stretched and flat without obvious wrinkles, and the position of the area, located at the negative position of the H-shaped fixing frame, of the diaphragm sample is empty and is not in contact with the surface of the fixing frame.
Furthermore, the volume of one electrolyte drop in the step 2 is 1-6 ul
Furthermore, the electrolyte liquid drop in the step 2 is required to drop on the part of the diaphragm sample which is not contacted with the fixed frame, namely the part of the area of the H shape
Further, the diffusion time of the electrolyte on the diaphragm in the step 3 is 30s-15min
Calculating the unilateral diffusion distance of the electrolyte in the MD direction according to the following formula 1, and calculating the unilateral diffusion distance of the electrolyte in the TD direction according to the following formula 2;
MD＝(MD’-MD0) [ 2 ] formula 1
TD＝(TD’-TD0) And/2 formula 2.
Furthermore, the diffusion distances of electrolyte droplets with the same volume at the same time in the same direction of the diaphragm are different, and the difference of the diffusion distances in the same direction can reflect the quality of the wettability of the diaphragm.
Compared with the prior art, the invention has the following positive effects:
the testing device and the testing method for the wettability of the lithium ion battery diaphragm have the advantages of being simple and easy to obtain testing equipment, short in testing time, simple in calculation and convenient to operate.
Drawings
FIG. 1 is a schematic view of a diaphragm fixing frame
FIG. 2 is a schematic diagram of a testing device for wettability of a lithium ion battery diaphragm
Icon: 1 diaphragm fixing frame 2 diaphragm sample 3 magnifier 4 image display analysis system
FIG. 3 shows the results obtained in step 2 of example 1
FIG. 4 shows the results obtained in step 3 of example 1
FIG. 5 shows the results obtained in step 2 of example 2
FIG. 6 shows the results obtained in step 3 of example 2
FIG. 7 shows the results obtained in step 2 of example 3
FIG. 8 is the results obtained in step 3 of example 3
Detailed Description
The following provides a specific embodiment of a device and a method for testing the wettability of a lithium ion battery diaphragm.
Example 1
A testing device for wettability of a lithium ion battery diaphragm comprises a diaphragm fixing frame, a diaphragm sample to be tested, a magnifying lens and an image display analysis system. Further, referring to fig. 1, the diaphragm fixing frame includes 3 support pieces in an "H" shape, wherein 2 support pieces are parallel to each other, the other 1 support piece is vertical, and the edge of the support piece in the vertical direction is stacked below the other 2 support pieces.
Further, referring to fig. 2, the magnifier is connected to the image display analysis system, and the image magnified by the magnifier is displayed and analyzed on the image display analysis system
The invention provides a method for testing the wettability of a lithium ion battery diaphragm, which judges the wettability of the diaphragm according to the unilateral diffusion distance of electrolyte in the MD and TD directions of the diaphragm. The method comprises the following steps:
Further, the diaphragm sample in the step 1 is fixed on a diaphragm fixing frame, the surface of the diaphragm is stretched and flat without obvious wrinkles, and the position of the area, located at the negative position of the H-shaped fixing frame, of the diaphragm sample is empty and is not in contact with the surface of the fixing frame.
Furthermore, the volume of one electrolyte drop in the step 2 is 2ul
Furthermore, the electrolyte liquid drop in the step 2 is required to drop on a part where the diaphragm sample is not contacted with the fixing frame, namely an H-shaped part
Further, the diffusion time of the electrolyte on the diaphragm in the step 3 is 5min
The results obtained in step 2 of this example are shown in FIG. 3, and the results obtained in step 3 are shown in FIG. 4
The unilateral diffusion distance in the MD direction of the electrolyte is calculated according to the formula 1, and the unilateral diffusion distance in the TD direction of the electrolyte is calculated according to the following formula 2
MD＝(MD’-MD0) [ 2 ] formula 1
TD＝(TD’-TD0) [ 2 ] formula 2
MD＝(11.183-3.514)/2＝3.8345
TD＝(8.861-3.667)/2＝2.597
Example 2
A testing device for wettability of a lithium ion battery diaphragm comprises a diaphragm fixing frame, a diaphragm sample to be tested, a magnifying lens and an image display analysis system. Further, referring to fig. 1, the diaphragm fixing frame includes 3 support pieces in an "H" shape, wherein 2 support pieces are parallel to each other, the other 1 support piece is vertical, and the edge of the support piece in the vertical direction is stacked below the other 2 support pieces.
Further, referring to fig. 2, the magnifier is connected to the image display analysis system, and the image magnified by the magnifier is displayed and analyzed on the image display analysis system
The invention provides a method for testing the wettability of a lithium ion battery diaphragm, which judges the wettability of the diaphragm according to the unilateral diffusion distance of electrolyte in the MD and TD directions of the diaphragm. The method comprises the following steps:
Further, the diaphragm sample in the step 1 is fixed on a diaphragm fixing frame, the surface of the diaphragm is stretched and flat without obvious wrinkles, and the position of the area, located at the negative position of the H-shaped fixing frame, of the diaphragm sample is empty and is not in contact with the surface of the fixing frame.
Furthermore, the volume of one electrolyte drop in the step 2 is 6ul
Furthermore, the electrolyte liquid drop in the step 2 is required to drop on a part where the diaphragm sample is not contacted with the fixing frame, namely an H-shaped part
Further, the diffusion time of the electrolyte on the diaphragm in the step 3 is 15min
The results obtained in step 2 of this example are shown in FIG. 5, and the results obtained in step 3 are shown in FIG. 6
The unilateral diffusion distance in the MD direction of the electrolyte is calculated according to the formula 1, and the unilateral diffusion distance in the TD direction of the electrolyte is calculated according to the following formula 2
MD＝(MD’-MD0) [ 2 ] formula 1
TD＝(TD’-TD0) [ 2 ] formula 2
MD＝(5.653-4.186)/2＝0.7335
TD＝(6.417-3.820)/2＝1.2985
Example 3
A testing device for wettability of a lithium ion battery diaphragm comprises a diaphragm fixing frame, a diaphragm sample to be tested, a magnifying lens and an image display analysis system.
Further, referring to fig. 1, the diaphragm fixing frame includes 3 support pieces in an "H" shape, wherein 2 support pieces are parallel to each other, the other 1 support piece is vertical, and the edge of the support piece in the vertical direction is stacked below the other 2 support pieces.
Further, referring to fig. 2, the magnifier is connected to the image display analysis system, and the image magnified by the magnifier is displayed and analyzed on the image display analysis system
The invention provides a method for testing the wettability of a lithium ion battery diaphragm, which judges the wettability of the diaphragm according to the unilateral diffusion distance of electrolyte in the MD and TD directions of the diaphragm. The method comprises the following steps:
Further, the diaphragm sample in the step 1 is fixed on a diaphragm fixing frame, the surface of the diaphragm is stretched and flat without obvious wrinkles, and the position of the area, located at the negative position of the H-shaped fixing frame, of the diaphragm sample is empty and is not in contact with the surface of the fixing frame.
Furthermore, the volume of one electrolyte drop in the step 2 is 1ul
Furthermore, the electrolyte liquid drop in the step 2 is required to drop on a part where the diaphragm sample is not contacted with the fixing frame, namely an H-shaped part
Further, the diffusion time of the electrolyte on the separator in the step 3 is 30s
The results obtained in step 2 of this example are shown in FIG. 7, and the results obtained in step 3 are shown in FIG. 8
The unilateral diffusion distance in the MD direction of the electrolyte is calculated according to the formula 1, and the unilateral diffusion distance in the TD direction of the electrolyte is calculated according to the following formula 2
MD＝(MD’-MD0) [ 2 ] formula 1
TD＝(TD’-TD0)/2 Formula 2
MD＝(6.203-3.606)/2＝1.2985
TD＝(6.976-3.575)/2＝1.7005
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and decorations can be made without departing from the concept of the present invention, and these modifications and decorations should also be regarded as being within the protection scope of the present invention.
Claims (7)
1. A testing device for wettability of a lithium ion battery diaphragm is characterized by comprising a diaphragm fixing frame, a diaphragm sample to be tested, a magnifying lens and an image display analysis system; the membrane sample to be detected is fixed on the membrane fixing frame and arranged under the visual field of the magnifier, the magnifier is connected with the image display analysis system, and the image amplified by the magnifier is displayed and analyzed on the image display analysis system.
2. The device for testing lithium ion battery separator wettability of claim 1, wherein the separator holder includes 3 support pieces in an "H" shape, wherein 2 support pieces are parallel to each other, the other 1 support piece is vertical, and the edge of the support piece in the vertical direction is stacked under the other 2 support pieces.
3. A method for testing wettability of a lithium ion battery diaphragm is characterized by comprising the following specific steps:
step 1, taking a diaphragm sample, fixing the diaphragm sample on a diaphragm fixing frame, placing the diaphragm sample under the visual field of a magnifier, adjusting the focal length of the magnifier to enable an image display analysis system to display a clear diaphragm image, and distinguishing the MD and TD directions of the diaphragm in the image;
step 2, dropping an electrolyte drop on the surface of the diaphragm, starting timing, shooting the form of the electrolyte just contacting the diaphragm by using an image display analysis system, measuring the dimension of the electrolyte drop along the MD and TD directions of the diaphragm respectively, and recording the dimension as MD0,TD0；
Step 3, waiting for a period of time, stopping timing, wherein the period of time is the diffusion time of the electrolyte on the diaphragm, shooting and recording the shape of the electrolyte on the diaphragm at the time of stopping timing, and measuring the sizes of the electrolyte along the MD and TD directions respectively and recording the sizes as MD 'and TD'
Calculating the unilateral diffusion distance of the electrolyte in the MD direction according to the following formula 1, and calculating the unilateral diffusion distance of the electrolyte in the TD direction according to the following formula 2;
MD＝(MD’- MD0) [ 2 ] formula 1
TD＝(TD’- TD0) And/2 formula 2.
4. The method for testing wettability of a lithium ion battery separator as claimed in claim 3, wherein the separator sample obtained in step 1 is fixed on a separator fixing frame, the surface of the separator is stretched and flat without obvious wrinkles, and the separator sample is emptied in a negative area of the "H" shaped fixing frame and does not contact with the surface of the fixing frame.
5. The method for testing the wettability of the lithium ion battery separator according to claim 3, wherein the volume of one electrolyte droplet in the step 2 is 1-6 ul.
6. The method for testing wettability of a lithium ion battery separator according to claim 3, wherein the electrolyte droplets in the step 2 are required to drop on a part of the separator sample, which is not in contact with the fixing frame, i.e., an "H" -shaped region.
7. The method for testing wettability of a lithium ion battery separator according to claim 3, wherein the diffusion time of the electrolyte on the separator in the step 3 is 30s-15 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910839803.9A CN112461713A (en) | 2019-09-06 | 2019-09-06 | Device and method for testing wettability of lithium ion battery diaphragm |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910839803.9A CN112461713A (en) | 2019-09-06 | 2019-09-06 | Device and method for testing wettability of lithium ion battery diaphragm |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112461713A true CN112461713A (en) | 2021-03-09 |
Family
ID=74806768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910839803.9A Pending CN112461713A (en) | 2019-09-06 | 2019-09-06 | Device and method for testing wettability of lithium ion battery diaphragm |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112461713A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113140865A (en) * | 2021-03-22 | 2021-07-20 | 万向一二三股份公司 | Method for improving wettability of lithium ion battery diaphragm and diaphragm wettability evaluation method |
| CN113702248A (en) * | 2021-09-02 | 2021-11-26 | 山东圣阳电源股份有限公司 | Method for testing wettability of diaphragms made of different materials for lithium ion battery |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102621040A (en) * | 2012-04-06 | 2012-08-01 | 苏州生益科技有限公司 | Method for testing wettability of electronic-grade glass fiber cloth |
| CN202512040U (en) * | 2012-04-06 | 2012-10-31 | 苏州生益科技有限公司 | Device for testing wettability of electronic-grade glass fiber cloth |
| CN104266942A (en) * | 2013-05-10 | 2015-01-07 | 中华人民共和国南通出入境检验检疫局 | Method for testing moisture absorptivity of polyester fabric subjected to anti-ultraviolet moisture-absorption quick-drying differentiated finishing |
| CN105043935A (en) * | 2015-05-18 | 2015-11-11 | 华南理工大学 | Device and method of measuring infiltration performance of porous metal material on the basis of digital image processing |
| CN106872335A (en) * | 2017-03-17 | 2017-06-20 | 华南理工大学 | Porous material wetting property measurement apparatus and method based on infrared image processing |
-
2019
- 2019-09-06 CN CN201910839803.9A patent/CN112461713A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102621040A (en) * | 2012-04-06 | 2012-08-01 | 苏州生益科技有限公司 | Method for testing wettability of electronic-grade glass fiber cloth |
| CN202512040U (en) * | 2012-04-06 | 2012-10-31 | 苏州生益科技有限公司 | Device for testing wettability of electronic-grade glass fiber cloth |
| CN104266942A (en) * | 2013-05-10 | 2015-01-07 | 中华人民共和国南通出入境检验检疫局 | Method for testing moisture absorptivity of polyester fabric subjected to anti-ultraviolet moisture-absorption quick-drying differentiated finishing |
| CN105043935A (en) * | 2015-05-18 | 2015-11-11 | 华南理工大学 | Device and method of measuring infiltration performance of porous metal material on the basis of digital image processing |
| CN106872335A (en) * | 2017-03-17 | 2017-06-20 | 华南理工大学 | Porous material wetting property measurement apparatus and method based on infrared image processing |
Non-Patent Citations (3)
| Title |
|---|
| 张玄奇: "《石油工程实验教程》", 30 November 2001, 西北大学出版社, pages: 80 - 82 * |
| 王金良等: "《中国电池工业20年》", 30 June 2009, 中国轻工业出版社, pages: 321 - 323 * |
| 高会普: "高性能复合熔喷锂离子电池隔膜的研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》, no. 4, 15 April 2016 (2016-04-15), pages 042 - 684 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113140865A (en) * | 2021-03-22 | 2021-07-20 | 万向一二三股份公司 | Method for improving wettability of lithium ion battery diaphragm and diaphragm wettability evaluation method |
| CN113702248A (en) * | 2021-09-02 | 2021-11-26 | 山东圣阳电源股份有限公司 | Method for testing wettability of diaphragms made of different materials for lithium ion battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112461713A (en) | Device and method for testing wettability of lithium ion battery diaphragm | |
| CN202421021U (en) | Device for measuring wetting property of battery electrolyte to battery material | |
| CN206930555U (en) | Lithium battery diaphragm pole piece wet-out rate test device | |
| CN202512040U (en) | Device for testing wettability of electronic-grade glass fiber cloth | |
| CN103512821A (en) | Method for testing liquid absorption rate of battery diaphragm | |
| CN208334320U (en) | Negative aeroion comprehensive detector | |
| CN109100252B (en) | Equipment and method capable of accurately detecting liquid absorption performance of lithium ion battery pole piece and diaphragm | |
| CN106124291B (en) | A kind of device and method of continuous measurement deformation of thin membrane | |
| CN211122308U (en) | Battery diaphragm tensile strength detection device | |
| CN113702248A (en) | Method for testing wettability of diaphragms made of different materials for lithium ion battery | |
| CN111413257A (en) | Cell nucleus electrical property detection device and method | |
| CN112098301A (en) | Method for testing porosity of diaphragm | |
| CN109920970B (en) | Method for calculating liquid injection time of square aluminum-shell battery | |
| CN209992500U (en) | Soil detection device | |
| CN203323689U (en) | Detection device used for discriminating between concave face and convex face | |
| CN102494597A (en) | Detecting device and detecting method for evenness of fuel cell bipolar plate | |
| RU186174U1 (en) | Device for rapid assessment of gas permeability of proton-conducting membrane of a fuel cell | |
| CN215338226U (en) | Engineering is managed with wall and is leveled measuring device | |
| CN212134412U (en) | Silicon chip hydrophilicity detection device | |
| CN212514135U (en) | Diaphragm wettability measuring device | |
| CN211426315U (en) | Defect detection equipment for gas diffusion layer of hydrogen fuel cell | |
| CN211043022U (en) | Device for constant dead volume | |
| CN108152174A (en) | Portable solid surface contact angle measuring device and measuring method | |
| CN112886107A (en) | Optimized button cell assembling method | |
| CN106323820A (en) | Method for testing hydrophobicity of vulcanizing silicone rubber coating field sampling samples |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |