Electrolyte with polyanion functional group and preparation method and application thereof

Abstract

The invention discloses an electrolyte with a polyanion functional group and a preparation method and application thereof, and relates to a nonaqueous secondary battery electrolyte. For example, the preparation method of Li[PF2(PO2F2)2(C2O4)] comprises the following steps: (1) dissolving Li3PO4 into dimethyl carbonate, adding LiPF6, and recycling a settled solution for recrystallization after reaction so as to obtain LiPO2F2; (2) dissolving the LiPO2F2 obtained in the first step into dimethyl ether, then introducing PF5 gas, and recycling a settled solution for recrystallization so as to obtain LiPF4(PO2F2)2; and (3) under an inert atmosphere condition, dissolving the LiPF4(PO2F2)2 obtained in the second step into the dimethyl ether, then adding oxalic acid, and reacting to obtain the product LiPF2(PO2F2)2(C2O4). The electrolyte with the polyanion functional group can be used in the preparation of a nonaqueous electrolyte and a nonaqueous secondary battery.

Description

technical field [0001] The invention relates to a non-aqueous secondary battery electrolyte, in particular to a type of electrolyte with polyanion functional groups, a preparation method and application thereof. Background technique [0002] Reducing the consumption of fossil energy and reducing the emission of greenhouse gases such as carbon dioxide have become one of the most urgent problems for all human beings to solve. Today, as the energy environment continues to deteriorate, the role of the lithium-ion battery industry in the field of new energy has become increasingly prominent. It is a practical and feasible method to develop electric vehicles and use batteries to provide power to replace petroleum. It is important to ensure energy security and develop a low-carbon economy. way. [0003] At present, my country and major developed countries in the world have issued many policies to support new energy vehicles. New energy vehicles are listed as one of the seven new i...

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Problems solved by technology

[0006] It should be pointed out that PO x f y - The group radius is small, and it is difficult to dissociate in non-aqueous organic solvents. Whether it is used as an electrolyte main salt or an auxiliary electrolyte, it will lead to a decrease in the ionic conductivity of the electrolyte, which will affect the battery capacity and Coulombic efficiency.

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