-
E-mail
xmyimai@163.com
-
Phone
18050037020
-
Address
Room 1401, No. 198, Building 7, Jiaxin Garden, Dongfu New City, Haicang District, Xiamen City
Xiamen Yimai Environmental Protection Technology Co., Ltd
xmyimai@163.com
18050037020
Room 1401, No. 198, Building 7, Jiaxin Garden, Dongfu New City, Haicang District, Xiamen City
About lithium battery materials
Lithium ion batteries generally consist of five parts: positive electrode, negative electrode, electrolyte, separator, shell, and electrode lead. The positive electrode includes lithium cobalt oxide or nickel cobalt manganese oxide, lithium manganese oxideLithium iron phosphateA current collector composed of aluminum foil. The negative electrode is composed of a current collector made of graphitized carbon material and copper foil. The battery is charged with an organic electrolyte solution.
With the update and iteration of new technologies, the performance and stability of batteries can be further improved by adding conductive salts (such as lithium hexafluorophosphate) and other additives. The interior of lithium-ion batteries must require an environment with a water content of less than 20mg/kg, as commonly used conductive salts react with water to generateHFDue to its toxicity and corrosiveness, it can damage battery cells. At the same time, high moisture content not only reduces battery capacity, decreases the number of battery cycles, and leads to the decomposition of lithium salts in the electrolyte, but also affects the structural stability of positive and negative electrode materials, and corrodes aluminum current collectors. Therefore, moisture content is one of the most critical indicators in the production and quality control of lithium batteries.
N-bis (trifluoromethanesulfonyl) imide sodium is one of the key components in the electrolyte of sodium ion batteries. Compared with other sodium salts such as sodium perchlorate and sodium hexafluorophosphate, its advantages include high electrochemical stability and suitability for high voltage environments; Good compatibility with multiple solvents; A stable interface can be formed without the need for additional film-forming additives.
Due to the extremely low moisture content of the materials and reagents used in lithium battery productionChoose the Karl Fischer Coulomb method for moisture determination. According to the properties of different samples, different testing methods can be used, which can dissolve in Coulombic reagentsThe samples can be directly measured using methods such as electrolytes, solvents, and other liquid samples,Lithium hexafluorophosphateWait for solid samples that can be dissolved, etc; For solid samples such as positive electrode materials, negative electrode materials, and battery separators that cannot be dissolved, their moisture content can be determined by the Karl Fischer method. Such as positive electrode materials, positive and negative electrode sheets, battery separators, etc.
Experimental techniques and suggestions:
►Samples containing aldehyde ketone structures, such as aldehydes such as formaldehyde, acetaldehyde, and benzaldehyde, as well as samples containing ketones such as acetone, butanone, and cyclohexanone, require the use of aldehyde ketone specific anode and cathode solutions (suitable for diaphragm titration cells).
►Many lithium battery materials have hygroscopicity and absorb moisture from the atmospheric environment during processing. Therefore, it is recommended to minimize the contact between the sample and atmospheric moisture as much as possible to obtain reliable and reproducible measurement results. It is recommended that sample preparation, and even the entire measurement process, should be carried out in a dry glove box.
►Some common electrolyte additives, such as vinyl chloride or borates, can undergo side reactions with alcohol substances in Karl Fischer reagents. It is recommended to reduce the sample size, increase the frequency of reagent replacement, and quickly titrate to the endpoint, which can greatly improve the reliability and accuracy of the measurement results.
Required reagents (Aquastar)®Coulombic titrant, reducing costs and increasing efficiency: only 1 bottle of reagent is needed, no need to distinguish between catholyte and anolyte)
Item Number |
Product description |
Titrant dosage |
remark |
1.09255.0508 |
Aquastar®Coulombic titrant, suitable for both cathodic and anodic solutions in diaphragm titration cells |
5 mL |
Used as catholyte |
100 mL |
Used as an anode liquid |
||
1.88055.0010 |
Aquastar®Standard water, 15-30 ppm, measured by Coulombic method and Karl Fischer furnace (120-160 ° C) |
/ |
CRM grade, packaging specification: 10 x 8mL |
1.88051.0010 |
Aquastar®Standard water 0.1% (1.0 mg water/g) |
/ |
CRM grade, packaging specification: 10 x 8mL |
Instrument parameter settings
Suggested parameter settings for titrators for endpoint indication, such as:
Polarization current I (pol)=5-10 μ A
Terminal control potential U (EP)=50-100 mV
Stable time: 30 seconds
Termination criteria for titration: drift value<10 μ g/min
3. Sample size: 1 gram
Method steps introduction:
Pour Karl Fischer reagent separately into the cathode and anode chambers with membrane titration cells. Start the titrator and titrate until the system is balanced and dry. After pre titration and drift value stabilization, inject the sample into the titration cell using a syringe (accurately weigh the sample by measuring the weight difference before and after the syringe), and begin the Coulombic titration method. The instrument directly reads the moisture content value of the sample to be tested.
Required reagents (Aquastar)®Coulombic titrant, reducing costs and increasing efficiency, one-stop procurement
Item Number |
Product description |
Titrant dosage |
remark |
1.09257.0508 |
Aquastar®Coulombic titrant, applicable with/without diaphragm titration cell, suitable for both cathodic and anodic solutions |
100 mL |
Choose one of the two reagents on the left side, and there is no need to prepare catholyte for the non diaphragm titration cell |
1.88079.0500 |
Aquastar®Coulombic method anode solution, used in diaphragm free titration cell (new formula can effectively avoid crystallization phenomenon, suitable for laboratories with high environmental humidity) |
100 mL |
|
1.88055.0010 |
Aquastar®Standard water, 15-30 ppm, measured by Coulombic method and Karl Fischer furnace (120-160 ° C) |
/ |
CRM grade, packaging specification: 10 x 8mL |
1.88051.0010 |
Aquastar®Standard water 0.1% (1.0 mg water/g) |
/ |
CRM grade, packaging specification: 10 x 8mL |
Instrument parameter settings
Suggested parameter settings for titrators for endpoint indication, such as:
Polarization current I (pol)=5-10 μ A
Terminal control potential U (EP)=50-100 mV
Stable time: 30 seconds
Termination criteria for titration: drift value<10 μ g/min
3. Sample size: 1 gram
Method steps introduction:
Pour Karl Fischer reagent into a diaphragm free titration cell. Start the titrator, titrate until the system is balanced and dry, and after pre titration and drift value stabilization, place the sample on a weighing dish (accurately weigh the sample by the weight difference before and after the weighing dish), and begin the Coulombic titration method. The instrument directly reads the moisture content value of the sample to be tested.
Other commonly used product recommendations
Item Number |
Product description |
Packing Specification |
1.88035.0500 |
buffer solution(Used for buffering strongly acidic samples, Adjust the pH value to 5-7) |
500mL |
1.88036.0500 |
Buffer solution (used for buffering strongly alkaline samples, Adjust the pH value to 5-7) |
500mL |
1.00136.0250 |
benzoic acid |
250G |
1.08297.2500 |
xylene |
2.5L |
1.09684.1000 |
formamide |
1L |
1.05704.0250 |
Molecular sieve, pore size 0.3nm, diameter 2mm, 粒径10 mesh |
250G |
1.05734.0250 |
Molecular sieve, pore size 0.3nm, diameter 2mm, Particle size 10 mesh, containing indicator |
250G |