Ion liquid electrolytic solution and secondary lithium battery containing electrolytic solution

Abstract

The invention discloses an ion liquid electrolytic solution and a secondary lithium battery containing the electrolytic solution. The ion liquid electrolytic solution is characterized in that a lithium secondary battery non-water electrolytic solution comprises an ion liquid containing electrolyte salt and a nitrile group functional group, a hydrogen fluorine ether, a non-water organic solvent and an addition agent; the ion liquid of the nitrile group functional group used by the electrolytic solution is beneficial to improving the security of the lithium secondary battery, the content of the ion liquid is more than 40%, and the electrolytic solution has the obvious flame retardant effect; the hydrogen fluorine ether is contributed to improving the wettability of the electrolytic solution containing the ion liquid on an electrode material and a diaphragm, and meanwhile, electrochemistry properties such as a cycle property, a high temperature keeping property of the lithium secondary battery are obviously improved; and an electrolytic solution system uses the ion liquid of the nitrile group functional group and the hydrogen fluorine ether in a composite manner, the combination properties such as the cycle property, the safety property and high temperature characteristics of the lithium secondary battery are obviously improved.

Description

technical field [0001] The present invention relates to an ionic liquid electrolyte and a secondary lithium battery containing the electrolyte, more specifically, the present invention relates to a high-voltage electrolyte containing ionic liquid and hydrofluoroether, and a lithium secondary battery stable under high pressure conditions . Background technique [0002] Lithium secondary batteries with high specific energy, high specific power, high safety and long cycle life are ideal power sources for future electric vehicles and various electric tools. With the long-time standby of electronic consumer products and the requirements of electric vehicle endurance, it is urgent to further improve the energy density of lithium secondary batteries. In addition to improving the production process and reducing the weight of the battery itself, another important solution is to try to increase the working voltage of the battery to increase the specific energy of the single battery, ...

AI Technical Summary

Problems solved by technology

Crease and Xu (J. Electrochem. Soc., 2002, 149, A920) in LiPF 6 - Add 1% hexafluoroisopropanol phosphate to EC / EMC and apply it to Li / LiNi 0.5 mn 1.5 o 4 In the battery, it was found that in the range of 4.4 to 4.9V, the capacity of the battery without additives decreased by 40% after 200 cycles, while the battery with hexafluoroisopropanol phosphate additives only decreased by about 15%, which indicated that six Fluoroisopropanol phosphate can effectively inhibit the oxidation reaction of carbonate on the electrode surface, but the specific mechanism of action remains to be studied

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