Stabilizer for non-water electrolysis and non-water electrolysis containing the stabilizer

Abstract

The invention provides a stabilizing agent used for nonaqueous electrolytic solution, and the stabilizing agent is composed of phosphite ester compound and amine compound. The invention also provides the nonaqueous electrolytic solution containing the stabilizing agent. The nonaqueous electrolytic solution contains 85-90 percent (weight) of organic solvent, 8-14 percent (weight) of lithium salt and 0.1-5 percent (weight) of the stabilizing agent. In the stabilizing agent of the invention, the phosphite ester compound can be oxidized preferentially to play a role of protecting other effective components in the nonaqueous electrolytic solution; and the amine compound can catch active protons in the nonaqueous electrolytic solution and can restrain the decomposition of LiPF6 and reduce the HF content of electrolytic solution. The phosphite ester compound and the amine compound are matched for use to prevent the acidity of the nonaqueous electrolytic solution from being overhigh and prevent the nonaqueous electrolytic solution from being oxidized to change the color so as to well stabilize the nonaqueous electrolytic solution, thereby the nonaqueous electrolytic solution containing the stabilizing agent can keep stable for a long time.

Description

technical field [0001] The invention relates to an electrolyte solution for batteries, in particular to a nonaqueous electrolyte solution and a stabilizer for the nonaqueous electrolyte solution. The nonaqueous electrolyte solution can be used in lithium-ion batteries. Background technique [0002] Lithium-ion batteries have been widely used in notebook computers, mobile phones, digital cameras, mp3 players and other small electronic equipment and medical equipment as driving power sources due to their superior performance since their birth and commercialization. [0003] Non-aqueous electrolyte is an important part of lithium-ion batteries, and its stable performance is the guarantee for the normal operation of lithium-ion batteries. [0004] The solid electrolyte interface film (solid electrolyte interface, referred to as SEI film) in lithium-ion batteries plays a very important role in the capacity, cycle stability and safety of lithium-ion batteries. However, due to the...

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Problems solved by technology

In addition, LiPF 6 Its thermal stability is poor, and it decomposes at a temperature ≥30°C to produce hydrogen fluoride (HF), so at high temperatures, the content of acids (such as HF) in the non-aqueous electrolyte will also increase

[0005] On the other hand, non-aqueous electrolytes for lithium-ion batteries contain many organic solvents, inorganic additives, and lithium salts that are easily oxidized by air or other oxidants. After these organic solvents, inorganic additives, and lithium salts are oxidized, they directly affect the non-aqueous electrolytic process. The nature of the liquid reduces the capacity, cycle life, high and low temperature performance, overcharge prevention performance and rate discharge performance of the battery, and leads to obvious discoloration of the non-aqueous electrolyte

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