A kind of non-aqueous electrolytic solution for lithium secondary battery

Abstract

The invention relates to a non-aqueous electrolytic solution used for lithium secondary batteries, in particular to an electrolytic solution capable of improving the high-voltage cycle performance of lithium batteries and the storage performance of the electrolytic solution. The non-aqueous electrolytic solution disclosed by the invention contains 0.01-2% by weight of antioxidant based on the total weight of the electrolytic solution, and due to the incorporation of the additives, the storage stability of the electrolytic solution is obviously improved. The non-aqueous electrolytic solution also contains lithium salt, a non-aqueous organic solvent and also contains the following components in percentage by total weight of the electrolytic solution of 0.5-7 percent of film-forming additives, 0-15 percent of flame-retardant additives, 2-10 percent of overcharge protection additives, 0.01-0.02 percent of a stabilizing agent and 0.01-1 percent of a wetting agent. According to the non-aqueous electrolytic solution provided by the invention, batteries can stably work under the high voltage of 4.3V or above, due to the synergic action of the incorporated additives with various functions, the high-capacity lithium-ion batteries can bring high specific energy into full play and have outstanding safety and high-temperature performances and cycle life.

Description

technical field [0001] The invention relates to an electrolyte solution for a lithium secondary battery, in particular to an electrolyte solution capable of improving the high-voltage cycle performance and electrolyte storage performance of a lithium ion battery. [0002] Background technique [0003] As China entered the 3G era in 2009 and the gradual popularization of 3G mobile phones and netbooks, the small battery seems to be becoming a serious problem. In the 3G era, mobile phones, netbooks, and notebooks will be further widely used for Internet access, games, and audio and video. But all of these applications require longer periods of operation and require batteries that can support them for a longer period of time. The increase in hardware configuration, the increase in CPU processing speed, and the larger screen size and higher resolution also require power protection. Therefore, it is urgent to increase the capacity of the battery. At present, the most efficient...

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Problems solved by technology

[0006] However, as mentioned in the above-mentioned patent, after the use of ester solvents replaced by fluorine, the solubility of the electrolyte salt is reduced, and the viscosity increases, resulting in a decrease in the discharge efficiency of the battery.

The addition of additives 2,3-dihydrofuran or 1,4 dioxetane has a lower oxidation potential and lower boiling point, which will have a greater negative impact on the subsequent cycle performance and high temperature performance of the battery, and the electrolyte is also easy to Discoloration etc.

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