Lithium difluoro(oxalate)borate

Referred to as LiODFB, is a new type of lithium salt with the molecular formula C2BF2LiO4, the appearance is white powder or crystal, easily soluble in water, soluble in carbonate solvent, ether compounds, gamma-butylactone and other solvents. Lithium difluorooxalate borate structure and lithium bioxalate borate (LiBOB), lithium tetrafluoroborate (LiBF4) similar, has excellent high and low temperature performance, thermal stability, conductivity, cycling performance and a wide operating temperature limit, not only can be used as a film additive for lithium battery electrolyte, by forming a good solid electrolyte phase interface (SEI film), To improve the cycle performance and rate performance of the battery in a wide temperature range; It can also be used as a conductive salt to replace lithium hexafluorophosphate (LiPF6) in the electrolyte to widen the operating temperature limit of the battery and improve the conductivity of the electrolyte.

Lithium difluoroxalate borate has a high technical barrier and is mainly produced by solid phase reaction, water phase reaction and organic phase reaction. Solid phase reaction method refers to the process of producing LiODFB from compounds containing fluorine, boron, lithium and oxalate through ball milling, high temperature reaction and purification. Water phase reaction method refers to the method that LiODFB is formed by adding the compounds containing lithium, boron and oxalate into HF aqueous solution through chemical reaction. Organic reaction method refers to the method of producing LiODFB with BF3, H3BO3, LiB4 or LiBOB as raw materials and dialkyl carbonate, nitrile and other organic solvents. Organic reaction is the most commonly used method to produce LiODFB.