A kind of lithium-ion battery non-aqueous electrolyte and lithium-ion battery

Abstract

The invention provides a lithium ion battery nonaqueous electrolyte solution and a lithium ion battery containing the nonaqueous electrolyte solution. The nonaqueous electrolyte solution comprises a lithium salt, a nonaqueous solvent and additives. The nonaqueous electrolyte solution is characterized in that the additives comprise a first additive and a second additive, the first additive is chain-like fluorocarbonate with a structure shown as structural formula (1) and / or structural formula (2), and the second additive is an annular disulfonic acid phenyl ester compound with a structure shown as structural formula (3). The lithium ion battery prepared from the nonaqueous electrolyte solution provided by the invention has good high-temperature storage performance and high voltage resistance.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, in particular to a nonaqueous electrolytic solution for a lithium ion battery and a lithium ion battery containing the nonaqueous electrolytic solution. Background technique [0002] Lithium-ion batteries stand out from many battery types due to their advantages of high voltage, high capacity, low consumption, no memory effect, pollution-free and small size, and are widely used in many electronic products such as mobile phones, listeners, PDAs, and notebooks. [0003] The prior art discloses a lithium battery electrolyte and a lithium ion battery using a silicon-based material as the negative electrode material. The electrolyte includes: a lithium salt, a nonaqueous and nonaqueous solvent, and a film-forming additive, wherein the The non-aqueous solvent includes ethylene carbonate, the film-forming additive includes tris(pentafluorophenyl)borane (TPFPB), and the content of the tris(pentafluor...

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Problems solved by technology

In addition, the prior art also discloses that by adding a phenylsulfonic acid ester compound containing 1-4 fluorine atoms on the benzene ring and a monosulfonic ester group with an oxygen atom directly combined with the benzene ring to the non-aqueous electrolyte, it can Effectively improve the low-temperature cycle characteristics of lithium batteries, but it does not significantly improve the high-temperature storage performance and high-voltage resistance performance of lithium batteries, see patent CN200880113625.1

There are also patents that add cyclic sulfonic acid ester compounds or disulfonic acid compounds or nitrile compounds and fluorinated cyclic carbonates with more than 2 fluorine atoms and a third compound in the non-aqueous electrolyte, which can improve the cycle of the battery characteristics, see patent CN201110138119.1, but in this scheme, the fluorinated cyclic carbonate is prone to oxidative decomposition. When the voltage of the battery system is greater than 4.35V, the electrolyte system will be oxidative and decomposed, which seriously affects the performance of the lithium battery under high voltage.

There are also patents that add phosphazene structure compounds and cyclic disulfonates or chain disulfonates to non-aqueous electrolytes, which can effectively improve the flame retardancy and capacity retention of lithium batteries, see patent CN201080049110. 7, but this scheme cannot improve the high pressure resistance and high temperature of the non-aqueous electrolyte

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