Process for preparing lithium bis (oxalato) borate

Abstract

The invention discloses a process for preparing lithium bis (oxalato) borate. The process comprises the following steps: 1, uniformly mixing lithium hydroxide or lithium carbonate with oxalic acid oroxalic acid dehydrate; 2, adding ortho-boric acid or metaboric acid into the uniformly reacted raw materials in the step 1, and uniformly mixing; 3, performing dry pressing on the raw materials obtained in the step 2 under pressure to form tablets, and placing the pressed tablets in a drying box; 4, continuously adding phosphorus pentoxide into the drying box, and continuously performing drying toobtain a semi-finished product of lithium bis (oxalato) borate; 5, dissolving the semi-finished product obtained in the step 4 with anhydrous acetonitrile, filtering out insoluble substances, evaporating and concentrating until a white solid appears, recovering acetonitrile, and drying the obtained white solid in a drying oven to obtain a high-purity lithium bis (oxalato) borate product. Comparedwith the prior art, the process for preparing lithium bis (oxalato) borate has the advantages of simple operation, economy, environmental protection, low by-product content in the reaction and high reaction efficiency.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery electrolyte salts, in particular to a process for preparing lithium bisoxalate borate. Background technique [0002] With the development of microelectronics technology and the increase of miniaturized electronic equipment, lithium batteries can be fully developed and used due to their superior performance. As an important part of the battery, the electrolyte has a very important impact on the performance of the battery. Lithium hexafluorophosphate is currently the most widely used electrolyte for lithium-ion batteries, which has good electrical conductivity and electrochemical stability. However, lithium hexafluorophosphate still has obvious shortcomings such as sensitivity to water, excessive resistance of the SEI film formed at low temperature, and decomposition at 80°C, which greatly restricts its working conditions. It is easy to decompose and produce HF when exposed to high tem...

AI Technical Summary

Problems solved by technology

[0004] At present, the preparation methods of LiBOB mainly include liquid-phase method and general solid-phase method. The existing solid-phase method is difficult to complete the reaction, and the obtained LiBOB mass percentage is generally only about 95%, which cannot be directly used as lithium ion. Electrolyte for electrochemical devices such as batteries