A self-healing composite solid-state electrolyte, quasi-solid-state electrolyte and lithium battery

Abstract

The invention relates to the field of batteries, in particular to a self-repairing composite solid electrolyte, a quasi-solid electrolyte and a lithium battery. The self-healing composite solid electrolyte includes a self-healing polymer and an inorganic solid electrolyte, the self-healing polymer includes a self-healing group, and the self-healing group is selected from urea groups. The dry base of the self-repairing composite solid electrolyte of the present invention can be bent, has flexibility, and can inhibit the growth of lithium dendrites. The composite solid electrolyte has a self-repairing function and can improve the service life of the battery. A small amount of lithium-containing electrolyte is added to the self-repairing composite solid electrolyte. The quasi-solid electrolyte prepared by the salt electrolyte can maintain a high conductivity of the electrolyte, and at the same time reduce the content of the lithium salt-containing liquid electrolyte and improve the safety of the battery.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a self-repairing composite solid electrolyte, a quasi-solid electrolyte and a lithium battery. Background technique [0002] Li metal has a high specific capacity (3860mAh g -1 ) and the lowest electrochemical potential (-3.040V relative to the standard hydrogen electrode), it is an ideal negative electrode material for the preparation of lithium batteries. However, the development of lithium metal batteries is limited by the uncontrollable lithium electrodeposition behavior during repeated lithium extraction / intercalation cycles, which leads to the growth of lithium dendrites, resulting in battery short circuit and energy loss. And the formation of solid electrolyte interphase (Solid Electrolyte Interphase, SEI) will cause the decrease of the Coulombic efficiency of the battery and the deterioration of the cycle performance of the battery. In addition, the infinite volume expansion of...

AI Technical Summary

Problems solved by technology

However, the development of lithium metal batteries is limited by the uncontrollable lithium electrodeposition behavior during repeated lithium extraction / intercalation cycles, which leads to the growth of lithium dendrites, resulting in battery short circuit and energy loss.

Moreover, the formation of solid electrolyte interphase (Solid Electrolyte Interphase, SEI) will reduce the Coulombic efficiency of the battery and deteriorate the battery cycle performance.

In addition, the infinite volume expansion of the lithium metal negative electrode will cause the continuous accumulation of interfacial stress, resulting in the collapse of the SEI layer and the continuous increase of the battery interface resistance.

[0003] At present, the methods to improve the stability of lithium metal anode mainly include: introducing artificial SEI layer, interface protection layer, electrolyte additives, etc., and constructing 3D lithium metal pillar materials. However, due to the low conductivity and poor mechanical stability of the interface layer The battery can only be used at a lower current density due to the nature of the battery, while the continuous consumption of electrolyte additives will also make the battery performance continue to decline, and the introduction of additional pillar materials will also reduce the overall energy density of the battery

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