Electrolyte for high-nickel lithium ion battery, preparation method of electrolyte and high-nickel lithium ion battery

Abstract

The invention discloses an electrolyte for a high-nickel lithium ion battery, a preparation method of the electrolyte and the high-nickel lithium ion battery, the electrolyte comprises a non-aqueous organic solvent, a high-concentration lithium salt and an electrolyte additive, the electrolyte additive comprises unsaturated carbonate, a lithium salt and 2-methyl maleic anhydride, the content of the unsaturated carbonic ester, the lithium salt and the 2-methyl maleic anhydride is 0.5 wt%-10 wt%. The electrolyte can effectively improve the high-temperature stability of the high-nickel lithium ion battery, and the thermal runaway heat of the battery solvent is reduced.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery materials for energy storage, and particularly relates to an electrolyte for high-nickel lithium-ion batteries, a preparation method thereof, and a high-nickel lithium-ion battery. Background technique [0002] At present, the most promising high-nickel lithium-ion battery is the 811 battery, but the characteristics of high-nickel and low-cobalt lithium-ion batteries also have certain shortcomings. While high nickel brings high energy density, it also brings new challenges to battery safety. , the hidden danger of safety accidents in the battery is higher than that of the low-nickel battery; and the reduction of the cobalt content reduces the number of charging cycles of the battery, and the service life of the battery is relatively lower. Therefore, the "811" battery needs to be optimized in terms of stability and durability. In addition, when the lithium-ion battery is used in a hig...

AI Technical Summary

Problems solved by technology

The disadvantage of this technical solution is that the high-voltage cycle performance is low and there is still room for improvement. In addition, the price of lithium difluorooxalate borate and lithium difluorophosphate used in this technical solution is relatively high, which increases the cost of the electrolyte and is not conducive to large-scale industrialization.

The electrolyte enables the high-nickel cathode material to reach a capacity retention rate of 78.66% after cycling 100 cycles at a high temperature of 60°C and 0.5C, which is 33.81% higher than the capacity retention rate of conventional electrolytes under the same environment. The disadvantage of this solution is high temperature cycle Retention rate below 80%

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