Lithium ion secondary cell and its electrolyte

Abstract

The invention provides a lithium ion secondary cell and an electrolyte. The electrolyte of the lithium ion secondary cell comprises a non-aqueous organic solvent; lithium salt dissolved in the non-aqueous organic solvent; and an addictive dissolved in the non-aqueous organic solvent. The addictive comprises a cis-butene esters compound with a structure of formula I, formula II or formula III, the mass of the cis-butene esters compound accounts for 0.5-3% of that of the non-aqueous organic solvent, wherein R1 and R2 are respectively and individually selected from one of halogenated alkyl groups, halogenated alkylene, halogenated phenyl and halogenated biphenyl, the halogen is F, Cl or Br, and the halogenations are monosubstitution, partial substitution, or full substitution. The lithium ion secondary cell of the present invention comprises the electrolyte of the lithium ion secondary cell. The lithium ion secondary cell can effectively improve the first discharge capacity and storage performance under high temperature and high voltage.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a lithium-ion secondary battery and its electrolyte. Background technique [0002] As notebook computers, mobile phones, handheld game consoles, tablet computers and other electronic mobile devices can achieve more and more functions, people's requirements for lithium-ion secondary batteries as their main driving energy are also getting higher and higher. The application technology of lithium-ion secondary batteries in electric vehicles, smart grids, etc. is also becoming more and more mature. Prolonging the service life of lithium-ion secondary batteries and improving their safety performance have become one of the hot research topics in the industry. [0003] When we increase the energy density of the lithium-ion secondary battery, especially the voltage of the lithium-ion secondary battery, it is equivalent to increasing the activity of the electrochemical reaction of the electrolyte...

AI Technical Summary

Problems solved by technology

In actual use, electronic products are also faced with continuous use of heat or an increase in the ambient temperature of the lithium-ion secondary battery, which may cause the lithium-ion secondary battery to be in a high temperature state, and at high temperature, the electrolyte will be subject to stricter conditions. In severe cases, due to the expansion and deformation of the lithium-ion secondary battery, a short circuit occurs inside the lithium-ion secondary battery or the packaging of the lithium-ion secondary battery bursts, resulting in the leakage of flammable electrolyte, causing fire and other safety accidents

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