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

Abstract

The present invention relates to a kind of non-aqueous lithium battery electrolytic solution, comprise lithium salt, organic solvent and functional additive, described functional additive comprises 2-sulfobenzoic anhydride derivative, described 2-sulfobenzoic anhydride The general structural formula of the derivative is wherein, R 1 , R 2 , R 3 , R 4 independently selected from hydrogen, hydroxy, halogen, alkyl, alkoxy, haloalkyl, haloalkoxy, alkenyl, haloalkenyl, phenyl, halophenyl, biphenyl, halobiphenyl, Phenyl ether group, triphenyl group, halogenated phenyl ether group, halogenated triphenyl group, amino group, ester group or cyano group, the halogen is F, Cl or Br, and the halogenation is partially substituted or fully substituted . The electrolyte solution of the present invention can well inhibit the dissolution of metal ions in the positive electrode material, protect the positive electrode, effectively reduce the thickness expansion of the lithium battery, and improve the capacity retention rate of the secondary lithium battery.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a non-aqueous lithium battery electrolyte and a secondary lithium battery. Background technique [0002] With the rapid development of portable electronic devices, hybrid vehicles, electric vehicles, and space technology, secondary batteries have put forward higher requirements in terms of specific capacity, cycle life, and safety. Lithium-ion battery cathode materials currently widely used in practice are lithium cobaltate, lithium manganate, and lithium iron phosphate. And with the progress of the battery charge-discharge cycle, the metal ions in the positive electrode material are dissolved into the electrolyte, and the reaction between the positive electrode active material and the electrolyte is also accelerated, resulting in severe swelling of the battery during the cycle, and the battery capacity decays significantly. The performance is reduced, which...

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Problems solved by technology

And as the battery charge-discharge cycle proceeds, the metal ions in the positive electrode material are dissolved into the electrolyte, and the reaction between the positive electrode active material and the electrolyte is also accelerated, resulting in serious gas swelling of the battery during the cycle, and the battery capacity decays significantly. The performance is reduced, which seriously restricts the performance of the positive electrode material

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