A single-ion conducting polymer lithium-sulfur battery

Abstract

The invention provides a single ion conducting polymer lithium-sulfur battery, comprising a sulfur positive electrode, a negative electrode and a single ion conducting polymer electrolyte blend film.The negative electrode is a metal lithium plate. The single ion conducting polymer electrolyte blend film locates between the sulfur positive electrode and the negative electrode. Compared with the prior art, the single ion conducting polymer lithium-sulfur battery of the invention does not contain a small molecule lithium salt, thus avoiding concentration polarization caused by different electromigration rates of anions and cations, and helping improve the safety of the battery. In addition, the use amount of an organic solvent in the polymer lithium-sulfur battery is relatively low, thus reducing dissolution and loss of an active substance, helping improve the cycling stability, avoiding the "shuttle" effect caused by application of an ether electrolyte, avoiding concentration polarization caused by using a LiPF6 ester electrolyte, and having relatively high safety.

Description

technical field [0001] The invention relates to the technical field of lithium-sulfur batteries, in particular to a single-ion conductive polymer lithium-sulfur battery. Background technique [0002] The theoretical specific capacity of elemental sulfur as an electrode material is as high as 1675mAh g -1 , the energy density of the lithium-sulfur battery obtained by pairing with metallic lithium reaches 2600Wh kg -1 , the energy density of the sodium-sulfur battery obtained by pairing with metallic sodium is as high as 1262Wh kg -1 , metal-sulfur batteries are a class of potential high specific energy secondary power sources. However, the electronic conductivity of elemental sulfur is very low, about 10 -30 SM -1 , has become the primary problem restricting its use as a cathode material. For the problem of low electronic conductivity of elemental sulfur, there are two solutions. The first is to reduce the size of sulfur particles to promote the occurrence of electron tu...

AI Technical Summary

Problems solved by technology

[0004] At the same time, there is another factor that restricts the practical application of lithium-sulfur batteries, that is, the safety hazards brought by metal lithium anodes.

Traditional commercial electrolytes conduct ions through small-molecule lithium salts. In fact, anions do not participate in the electrode reaction and will be enriched on the electrode surface, causing concentration polarization, which in turn leads to the formation of dendrites.

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