Lithium ion secondary battery using lithium iron phosphate as anode material with overall consideration of high and low temperature performance

Abstract

The invention discloses an aqueous electrolyte solution of a secondary lithium ion battery with ferric phosphate considering as the positive material and with both the high temperature performance and the low temperature performance. The aqueous electrolyte solution comprises LiPF6 lithium salt, an organic solvent and a film-forming additive, and is characterized in that the electrolyte solution further comprises high temperature additive; the organic solvent is composed of one or a plurality of carbonic esters and one or more carboxylic esters with low melting point and high boiling point. The carboxylic esters with low melting point and high boiling point are selected from one or a combination of methyl butyrate, ethyl butyrate, propyl butyrate and butyl acetate. The high temperature additive is 1, 3- propane sultone and 1, 4- butane sultone. The electrolyte solution is used for maintaining both the circulation performance in a high temperature state and the low temperature laying performance of the secondary lithium ion battery with the ferric phosphate lithium as the positive material.

Description

technical field [0001] The invention relates to a non-aqueous electrolytic solution for a lithium-ion secondary battery, in particular to a non-aqueous electrolytic solution for a lithium-ion secondary battery in which lithium iron phosphate is used as a positive electrode material with both high and low temperature performance. Background technique [0002] With the gradual depletion of oil resources all over the world and the increasingly serious environmental pollution caused by automobile exhaust, electric vehicles (EV) and hybrid electric vehicles (HEV) and corresponding power sources have been developed rapidly. At present, EVs and HEVs mainly use lead-acid and nickel-metal hydride batteries as driving power sources, but their lifespan is short and they are likely to cause environmental pollution. With the emergence of energy crises worldwide, lithium-ion batteries are used as green and sustainable energy , has become the main development direction of the energy field ...

AI Technical Summary

Problems solved by technology

[0017] Chinese patent 01116314.3 discloses a non-aqueous electrolytic solution, which includes at least one of carbonate and carboxylate, by adding (divinyl) ethylene carbonate to form a film at the negative electrode, to improve the non-aqueous electrolytic solution However, it is difficult for the battery injected with the non-aqueous electrolyte of the invention to take into account both the cycle performance and the low-temperature shelving performance under the high temperature state.

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