A kind of electrolytic solution and secondary lithium battery and capacitor containing the electrolytic solution

Abstract

The invention provides an electrolyte and a secondary lithium battery and an electrochemical capacitor containing the electrolyte. The electrolyte contains a lithium salt and an organic solvent, wherein the lithium salt comprises fluorine lithium sulfimide and lithium perchlorate. The electrolyte containing the fluorine lithium sulfimide and the lithium perchlorate, provided by the invention, has excellent performances, such as high conductivity, high ionic migration number, low viscosity, and the like. Because the lithium perchlorate in the electrolyte can be used for effectively reducing or eliminating the corrosion of fluorine lithium sulfimide above 4V to a current collector aluminum foil, the electrolyte provided by the invention is superior to the commercial electrolyte system in various aspects by preferably matching with a series of functional additives.

Description

technical field [0001] The invention relates to an electrolyte, a secondary lithium battery and a capacitor containing the electrolyte, and more particularly relates to a non-aqueous organic solvent electrolyte, a lithium secondary battery and an electrochemical capacitor using the electrolyte. Background technique [0002] Since the concept of rechargeable and dischargeable secondary lithium batteries was proposed in the early 1970s, secondary lithium batteries, as a new type of chemical energy, have high energy density, high working voltage, long cycle life, and abundant raw material resources. As well as being environmentally friendly, it is widely used in people's production and life. As one of the three major components of the secondary lithium battery, the electrolyte plays a role of ion conduction between electrodes in the work of the secondary lithium battery, directly affecting the performance of the secondary lithium battery. [0003] At present, the electrolytes ...

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Problems solved by technology

[0005] However, lithium fluorosulfonyl imide represented by lithium bis(fluorosulfonyl)imide (LiFSI) has a serious disadvantage: in the charging and discharging process of secondary lithium batteries and electrochemical capacitors, the When the voltage is high, the electrolyte system containing this salt has serious corrosion phenomena on all kinds of current collectors commonly used in secondary lithium batteries and electrochemical capacitors, especially the electrolyte system composed of this type of salt is harmful to the most common The corrosion of the aluminum foil of the cathode current collector is inevitable, which seriously affects the cycle life and efficiency of the only ion batteries that can be used commercially, that is, secondary lithium batteries and electrochemical capacitors, and limits the wide application of electrolytes composed of this type of lithium salt.

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