YS/T 1028.2-2015 in English
VALIDMethods for chemical analysis of lithium iron phosphate―Part 2:Determination of lithium content―Flame photometry
- Issued on:2015-04-30
- Implemented on:2015-10-01
- File Format:PDF
- Delivery:Via email within 1~3 business days
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本部分规定了磷酸铁锂中锂量的测定方法。本部分适用于磷酸铁锂中锂量的测定。测定范围：3%～5%。
Introduction
Technical background of the standard
As the core component of the lithium iron phosphate material testing system, this standard establishes a standardized lithium content testing method for key raw materials of new energy batteries. It was issued by the Ministry of Industry and Information Technology in 2015, filling the gap in the standardization of lithium battery positive electrode material composition analysis at that time.
Method principle analysis
Based on the atomic emission spectrometry principle of flame photometer: After the sample is dissolved in hydrochloric acid, the lithium element is excited in the high-temperature flame to produce a characteristic spectral line (670.8nm), and quantitative analysis is achieved by measuring the spectral line intensity. The introduction of sulfuric acid medium can effectively suppress the interference of alkali metals.
| Key steps | Technical parameters | Mechanism of action |
|---|---|---|
| Sample pretreatment | Hydrochloric acid (1+1) 20mL | Dissolve active substances while retaining the carbon skeleton |
| Medium adjustment | Sulfuric acid (1+1) 2mL | Form a stable ionization environment |
| Detection range | 3%~5% | Covering the typical content of commercial materials |
Analysis of key points of operation
Typical application case: The measured lithium content of a batch of lithium iron phosphate was 4.12%, and the difference between parallel measurement results was 0.05%, which met the repeatability limit requirement of 0.08%. Critical control points include:
- Sample particle size ≤ 0.10mm to ensure complete dissolution
- Micro-boiling time 3-5min to balance dissolution efficiency and volatilization loss
- Working curve linear correlation coefficient should be ≥ 0.999
Precision control
Precision indicators specified in the standard:
| Lithium content (%) | 2.98 | 4.01 | 5.01 |
|---|---|---|---|
| Repeatability limit r(%) | 0.06 | 0.08 | 0.12 |
The setting of 0.15% tolerance between laboratories takes into account the systematic error between different flame photometer models.
Implementation suggestions
- Quality control points:Each batch of tests should be verified with standard substances (such as GBW(E)080551)
- Equipment maintenance:The burner should be cleaned weekly, and the gas purity should be ≥99.9%
- Method improvement:For high-content samples, the standard addition method is recommended
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YS/T 1028.5-2015 in English
Methods for chemical analysis of lithium iron phosphate―Part 5:Determination of calcium、magnesium、zinc、copper、lead、chromium、sodium、aluminium、nickel、cobalt、manganese content―Inductively coupled plasma atomic emission spectrometry
2015-04-30
