Abstract:Electrolyte, known as the blood of lithium battery, plays a decisive role in the main performance of lithium ion battery. Lithium hexafluorophosphate (LiPF6) is the core material for the production of electrolyte, and the impurity ions in the electrolyte will have a great negative impact on the battery performance. Therefore, it is particularly important to master the monitoring methods of impurity elements in lithium ion lithium hexafluorophosphate electrolyte. The traditional digestion before testing will cause some element loss and pollution, and it is difficult to accurately quantify the elements with low content. The standard recommended diluent needs to use electronic methyl ethyl carbonate, which is expensive. In this paper, the contents of 17 impurity elements in lithium hexafluorophosphate electrolyte, including Aluminum, Arsenic, Calcium, Cadmium, Cobalt, Chromium, Copper, Iron, Mercury, Potassium, Magnesium, Molybdenum, Nickel, Sodium, Lead, Sulfur and Zinc, were determined by standard curve method in a direct injection system coupled with inductively coupled plasma atomic emission spectrometry (ICP-OES), in which lithium hexafluorophosphate electrolyte was solution diluted by a 30% (v/v) ethanol aqueous. The best working conditions of ICP-OES (including the temperature of the atomizing chamber, the flow of atomizing gas, the atomizer, the rotational speed of the peristaltic pump, the power supply, and the oxygen flow) were optimized in the experiment. The results showed that when the temperature of the atomizing chamber was 5 ℃, the flow of atomizing gas was 0.6 L?min-1, the atomizer used was OneNeb atomizer, the rotational speed of the peristaltic pump was 50 rpm?min-1, the power supply was 1150w, and the oxygen flow was 50 mL?min-1, the sensitivity and the consumption of test solution and wear of consumables can achieve the best effect. The results showed that the linear correlation coefficient (r) of the standard curves of 17 analytical elements was not less than 0.999, the detection limit of the method was 0.0163~0.0940 mg/L, the precision was less than 3.41%, and the spiking recovery was 90.2%~110%, The relative error of element content of different diluents is within 5%, which proves the method is effective, simple and fast for the analysis of trace elements in lithium hexafluorophosphate electrolyte.