The Detection And Research Of Lithium Ion Batteries Electrolyte By Ion Chromatography

Lithium ion battery is one of the hottest and most widely used chemical batteries in recent years. As a new development of liquid chromatography, ion chromatography has been widely concerned by people since it was introduced by H. Small in 1970s. It has become a very effective tool for detecting ionic compounds in many fields, including pharmaceuticals industry, environmental monitoring, bioscience, electronic industry, chemical industry, energy industry, power industry and so on. With the increasing demand of testing in the modern society, ion chromatography expands its application field gradually. Then it comes the challenge of more various and complex samples, which needs to optimize the separated condition and the methods of sample pretreatment. In this article, the determination of anions in the electrolyte of lithium ion battery was established by ion chromatography and its online column switching technique. The main research contents of this paper are divided into four chapters.In Chapter 1, the concept of ion chromatography and lithium-ion battery were introduced. What's more, a lot of pretreatment methods were also reviewed.In Chapter 2, a sensitive and accurate method based on ion chromatography with suppressed conductivity detection was set up for determination of five kinds of lithium salts in electrolyte of lithium-ion battery. The proposed method achieved the simultaneous determination of five lithium salts for the first time, with the advantages of simple operation, low cost, high accuracy and analysis efficiency.In Chapter 3, a method based on ion chromatography with single pump column switching was established for determination of five lithium salts in electrolyte of lithium-ion battery. The whole detection process was carried out by a set of single ion chromatography detection equipment adding a valve. After the first separation in AG19, some anions were preserved in the AG19, and others washed into analytic column. Then the anions could be separated well after a valve-switching. The results showed that this method had advantage of environmental friendly, faster detection and high efficiency.In Chapter 4, a method based on ion chromatography and its online preparation system was developed for the determination of chloride and nitrate in dimethyl carbonate. In this work, dimethyl carbonate could be removed clearly by using a polymer-based reversed-phase column NS1. The target anions would move out of the NS1 and then be collected by AG15. With a valve-switching, the anions in the AG15 were eluent to the analytic column and realized its separated and detected process. The experimental results showed this method were practical and convenient for sample pretreatment and selective and accurate for detection.