Additive composition, electrolyte

Abstract

The invention provides an additive composition and an electrolyte. The additive composition comprises 0.01-90 wt% of hydrofluoroether, 0.01-90 wt% of fluorinated carbonate, 0.01-90 wt% of fluorine-containing flame retardant, 0.01-10 wt% of fluorine-containing overcharge protection agent and 0-2 wt% of fluorine-containing surfactant. Compared with the prior art, the additive composition and the electrolyte have the advantages that the additive composition contains a variety of additives, and the additives interact with one another, so that the problem that the conductivity of the electrolyte is lowered caused by the addition of a single additive can be solved; the additive composition contains the hydrofluoroether and the fluorine-containing overcharge protection agent, so that the pressure resistance of the electrolyte is improved, the high temperature resistance of the electrolyte is improved due to the fluorine-containing flame retardant, and the safety performance of the electrolyte provided by the invention is improved due to the coaction of the hydrofluoroether, the fluorine-containing overcharge protection agent and the fluorine-containing flame retardant; and the additives are added in a composition manner, so that the workload can be reduced, and the cost of the electrolyte is reduced.

Description

technical field [0001] The invention belongs to the technical field of battery manufacture, and in particular relates to an additive composition and an electrolyte solution. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, high average output voltage, small self-discharge, no memory effect, wide operating temperature range, excellent cycle performance, fast charge and discharge, high charging efficiency, high output power, and long service life. As a reliable energy source, it has been widely used in the power supply of consumer electronics products, and the application of lithium batteries in electric bicycles and electric tools has also developed rapidly in recent years. However, under various complex application conditions, lithium-ion batteries are in danger of burning or even exploding, which restricts the development of lithium-ion batteries for power and energy storage. [0003] In the past, the external protection devic...

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Problems solved by technology

[0006] Studies have shown that it is difficult for a single additive to solve all the problems of the electrolyte, and may also bring about other problems, such as the addition of phosphate flame retardants will cause its viscosity to increase, resulting in a decrease in the conductivity of the electrolyte; The flammable additive can use its surface activity to reduce the viscosity of the electrolyte, but it is not compatible with traditional carbonate solvents, and the electrolyte is easy to separate, resulting in a decrease in conductivity

[0007] The Chinese patent application number 200710028419.8 discloses a lithium battery electrolyte, in which alkyl phosphate is added, the high and low temperature performance of the battery is effectively improved, and it can be used in the range of -50 ° C to 120 ° C, but the alkyl phosphate The electrochemical compatibility of phosphate ester is poor, and when used as an additive, it will have a large negative impact on the electrochemical performance of the battery

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