A kind of lithium ion battery electrolyte additive and lithium ion battery electrolyte

Abstract

The invention relates to a lithium ion battery electrolyte additive and a lithium ion battery electrolyte. The lithium ion battery electrolyte includes a non-aqueous organic solvent, a lithium salt and an additive, and the non-aqueous organic solvent is ethylene carbonate, propylene carbonate and dimethyl carbonate. At least two of esters, diethyl carbonate, methyl ethyl carbonate, methyl formate, methyl acetate, methyl propionate, ethyl acetate, 1,3-propane sultone, adiponitrile and succinonitrile The combination of the species, the molar concentration of the lithium salt in the electrolyte is 0.95-1.05mol / L, the additive is composed of 2-thiophenecarbonitrile and the vinylsulfonyl fluoride additive, and the additive in the electrolyte of the lithium ion battery is in the electrolyte. The mass fraction of ions is 0.5-5%; the invention has the advantages of prolonging battery life, improving battery safety and improving battery cycle performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium ion battery electrolyte additive and a lithium ion battery electrolyte. Background technique [0002] Due to the advantages of high specific energy, long cycle life and no memory effect, lithium-ion batteries are widely used in mobile phones, computers, cameras, electric vehicles and other fields. The performance of ion batteries has put forward higher requirements. Among them, the most urgent is to improve the energy density of lithium ion batteries under the premise of ensuring safety; the commonly used method to improve the energy density of lithium ion batteries is to use high-voltage cathode materials. , such as LiCoPO 4 , LiNi 0.5 Mn 1.5 O 4 , LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 However, the current commercial carbonate-based electrolyte has a low electrochemical temperature window. When the battery voltage reaches about 4.5V, this type of ...

AI Technical Summary

Problems solved by technology

[0002] Due to the advantages of high specific energy, long cycle life, and no memory effect, lithium-ion batteries are widely used in many fields such as mobile phones, computers, cameras, and electric vehicles. The performance of ion batteries has put forward higher requirements, among which, the most urgent is to increase the energy density of lithium-ion batteries under the premise of ensuring safety; at present, the commonly used method to improve the energy density of lithium-ion batteries is to use high-voltage cathode materials , such as LiCoPO 4 、LiNi 0.5 mn 1.5 o 4 、LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 However, the current commercial carbonate-based electrolyte has a low electrochemical temperature window. When the battery voltage reaches about 4.5V, this type of electrolyte begins to undergo oxidation and decomposition side reactions on the surface of the positive electrode material, which affects the performance of lithium-ion batteries. Performance, reduce the cycle performance of lithium-ion batteries, and will bring certain safety hazards, and may even reduce the life of the battery rapidly, and reduce the capacity of the battery; therefore, to provide a battery that can prolong battery life, improve battery safety, A kind of lithium-ion battery electrolyte additive and lithium-ion battery electrolyte to improve battery cycle performance are very necessary

Images