A preparation method of ether-based electrolyte modified by a lewis acid-base complex additive and its application in lithium metal batteries

Abstract

The present invention discloses a preparation method of ether-based electrolyte modified by a Lewis acid-base complex additive and its application in lithium metal batteries. It belongs to the technical field of lithium secondary batteries and their electrolyte. The preparation method is as follows: a certain amount of Lewis acid and Lewis base are directly added to the basic electrolyte, stirred evenly, and then left to stand. The Lewis acid-base coordination reaction between the two generates a Lewis acid-base complex multifunctional additive in situ in the basic electrolyte, thereby preparing the modified ether-based electrolyte with the Lewis acid-base complex multifunctional additive. That is, the ether-based electrolyte optimized and modified by the Lewis acid-base complex additive prepared by the present invention can synergistically enhance the functional properties and stability of the interface film (CEI and SEI), reduce the occurrence of side reactions, electrolyte consumption and active lithium loss, inhibit the dissolution of positive transition metals and the growth of lithium dendrites on the surface of the lithium metal negative electrode (LMA); moreover, it can also be adapted to high-load positive electrodes, further significantly improving the energy density, coulombic efficiency, cycle life and safety of LMBs.