High-voltage electrolyte for lithium-ion battery and application thereof

Abstract

The invention discloses a high-voltage electrolyte for a lithium-ion battery and an application thereof. The high-voltage electrolyte comprises a nonorganic solvent, an electrolyte lithium salt and anelectrolyte additive, wherein the electrolyte additive comprises 0.3-2.0% of PST and 0.3-2.0% of LiDFP on the basis of the total weight of the high-voltage electrolyte. According to the invention, through the optimal combination of PST and LiDFP in the electrolyte additive, the excellent cycle performance acquired by the high voltage battery is guaranteed, and meanwhile, the high-temperature storage property of the high voltage battery is effectively improved, the capacity retention ratio of the battery after high-temperature storage is increased and the thickness swelling rate thereof is reduced. The charging cut-off voltage of the lithium-ion battery using the high-voltage electrolyte disclosed by the invention is more than 4.2V but less than or equal to 4.4V, the high-voltage electrolyte is capable of protecting the anode and preventing the metal ions from dissolving out and the high-voltage electrolyte also can form a stable SEI film on a cathode so that the excellent cycle performance and high-temperature storage property of the high-voltage electrolyte can be guaranteed.

Description

technical field [0001] The invention relates to the technical field of chemical power sources, in particular to a high-voltage electrolyte for lithium-ion power batteries and its application. Background technique [0002] In the 21st century, energy storage is one of many challenges, and the rapid development of various mobile energy-consuming devices makes it more important than ever before. Therefore, there is an urgent need to develop a high-performance, low-cost and environmentally friendly energy storage device to meet people's needs. Lithium-ion batteries have high energy density and service life, and have great application prospects in many fields such as new energy vehicles, wind energy, and solar energy. [0003] With the increase of electric vehicles, hybrid vehicles, electric tools and military applications, people put forward higher requirements for the energy density of lithium-ion batteries. The energy of lithium-ion batteries is determined by the battery cap...

AI Technical Summary

Problems solved by technology

At present, the electrolyte of commercial lithium-ion batteries, once the charging cut-off voltage exceeds 4.3V, the conventional carbonate-based electrolyte will oxidize and decompose, resulting in an increase in the internal resistance of the battery, resulting in a decrease in the cycle performance of the entire battery

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