Abstract: A novel preparation method of lithium bis(oxalato)borate (LiBOB) called acetonitrile solution method was introduced. Lithium source was firstly pretreated by P204 extraction resin. Then Li₂CO₃ was reacted with H₃BO₃ and H₂C₂O₄ directly in acetonitrile solution. As-prepared LiBOB was finally purified in ethylene glycol di-methyl ether (C₄H₁₀O₂). The synthesized LiBOB was characterized by infrared spectrum, X-ray diffraction (XRD) pattern, atomic absorption and ion chromatography. Thermal stability capability of as-synthesized LiBOB was analyzed by differential thermal analysis and thermogravimetry. The results indicate that the as-synthesized LiBOB has higher purity, lower impurity contents and better thermal stability than commercialized LiBOB, the purity of the as-synthesized LiBOB reaches 99.95%.

Key words: lithium bis (oxalato) borate, acetonitrile solution method, preparation, characterization