Electrolyte of flame-retarded lithium ion battery

Abstract

The invention relates to the technical field of electrolyte of flame-retarded lithium ion batteries, in particular to electrolyte of a flame-retarded lithium ion battery. The electrolyte comprises a lithium salt and an organic solvent, and is characterized in that three flame-retarded additives are also added into the electrolyte, wherein the three flame-retarded additives comprise fluoro-carbonate as a first additive, fluoro-benzene as a second additive and a nitrogenous and fluoride bearing organic compound as a third additive. By adopting the technical scheme, the fluoro-carbonate FEC is added into the existing electrolyte system to increase the viscosity of the electrolyte system to a certain extent so that the flash point of the electrolyte system is reduced; the additive fluoro-benzene with comparatively stable electrochemical properties is added to increase the noninflammability of the electrolyte to a certain extent and simultaneously ensure that the viscosity of the electrolyte system is moderate; and the nitrogenous and fluoride bearing organic compound is added to increase the noninflammability of the electrolyte on the basis of guaranteeing the electrochemical properties of the electrolyte.

Description

【Technical field】 [0001] The invention relates to the technical field of lithium-ion battery electrolytes, in particular to an electrolyte for flame-retardant lithium-ion batteries. 【Background technique】 [0002] Lithium-ion batteries emit a lot of heat when they are over-charged and discharged, short-circuited or operated at high current for a long time. These heats become a safety hazard for flammable electrolytes, which may cause catastrophic thermal breakdown and even battery explosion. Therefore, safety issues have become an important prerequisite for innovation in the lithium-ion battery market, especially in applications such as electric vehicles, which put forward higher and newer requirements for battery safety. At present, power batteries have begun to achieve commercial scale. Due to the different materials used by various manufacturers, the batteries will also have great differences. However, no matter what positive and negative electrode materials are used, th...

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Problems solved by technology

However, the viscosity of these phosphorus-based flame retardants is large, and the conductivity will be greatly reduced after adding the electrolyte, and the electrochemical stability is poor. For example, TMP will undergo reduction and decomposition similar to polycarbonate on the surface of the carbon negative electrode, resulting in Capacity loss, decrease in electrochemical performance

According to the current research results, the instability of flame retardant additives and its own other properties will have a certain negative impact on battery performance, and the improvement of battery safety is always at the expense of battery performance. Hope, and thus restrict the large-scale development of power batteries

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