The Synthesis And Properties Of Croconic Acid Derivatives Lithium Borate Electrolyte

Previous studies have showed that inorganic lithium salts such as LiClO4、 LiAsF6、LiBF4 exhibited good superiority in chemical and electrochemical properties. But some of its own defects have led to some obstacle in their practical application. Although LiPF6 has achieved commercialization as a lithium salt, but its thermal stability is poor. It is also easy to produce HF corrosive gas in solution, which may cause potential security risk. Since the performance of organic lithium salts, they have been widely concerned by researchers.The paper emphatically introduced that three kinds of electrolytes lithium salts were Designed and synthesized. Their various electrochemical performances were tested.This paper is divided into four chapters as follows:The first chapter, it is fully understood about the history and development of lithium-ion batteries from a lot of literature. Each component of the battery was introduced.The second chapter, new lithium salts have been designed and synthesized:e.g. lithium bis[1,2,3-tris(dicyanomethylene)-4-cyclopentene-4,5-diol(2-)-O,O]borate, lithium[1,2,3-tris(dicyanomethylene)-4-cyclopentene-4,5-diol(2-)-O,Ooxalato]borate, lithium[1,2,3-tris(dicyanomethylene)-4-cyclopentene-4,5-diol(2-)-O,O1,2-benzenedi olato]borate. Simultaneously, structure of three lithium salts were detected by IR, NMR and other methods. It was measured of the percentage of ligand C, H, O, N by elemental analysis. Using XSP Intrepid Ⅱ inductively coupled plasma emission spectrometer measured the liquid electrolyte, lithium and boron contents of lithium salts.The third chapter, the thermal stability, solubility, conductivity and oxidation potential of new lithium salts had been tested in order to obtain the performance of new lithium salts in thermodynamic and electrochemical aspects.The fourth chapter, the results of the research were summarized, and the shortcomings of the research were simply summarized. As well as the possible future research direction was forecasted.In summary, three new organic boron lithium salts were synthesized successfully in this paper and their various properties had been tested. The test results showed that the newly synthesized substances were basically accord for the requirements as commercial lithium salts.