Silicon dioxide molecular sieve with mono-layer carbon deposited in the channels and carbon nanotubes on the outside for lithium–sulfur batteries

Abstract

A novel sulfur host matrix prepared by the deposition of mono-layer carbon into silicon dioxide molecular sieve channels and carbon nanotubes on the molecular sieve surface is proposed as an electrode material for lithium sulfur batteries.

Polysulfides Capture-Copper Additive for Long Cycle Life Lithium Sulfur Batteries

“…Sulfur, as a new energy storage material, possesses a high specific capacity of 1675 mAh g –1 , which is 4–5 times greater than that of conventional Li-ion battery materials based on insertion/extraction reactions. , Moreover, sulfur is cheap, environmental friendly, and abundant, which make the lithium sulfur battery the most promising next-generation energy storage system. − However, the electrochemical reaction between sulfur and metal lithium suffers from two serious problems that hinder its commercial application. , It is the intrinsic insulating characteristic of sulfur and the shuttle phenomenon that decrease the utilization of sulfur and seriously impact the battery Coulombic efficiency. To commercialize the lithium sulfur (Li–S) battery, extensive approaches have been developed, such as design novel sulfur host materials, , introducing electrolyte additives and electrode surface modification. − It is well-known that the redox reaction in the Li–S battery is complicated and its mechanism is still not sufficiently understood. Element sulfur (S 8 ), undergoes a multiple-electron reduction process to the final product Li 2 S. Sulfur will electrochemically be reduced gradually and generate polysulfides with different length chains, depending on the degree of discharge. − Those intermediate polysulfides are soluble and could move back and forth between anode and cathode electrodes, causing degradation in cycle performance and Coulombic efficiency.…”

“…7,8 It is the intrinsic insulating characteristic of sulfur and the shuttle phenomenon that decrease the utilization of sulfur and seriously impact the battery Coulombic efficiency. To commercialize the lithium sulfur (Li−S) battery, extensive approaches have been developed, such as design novel sulfur host materials, 9,10 introducing electrolyte additives 11 and electrode surface modification. 12−14 It is well-known that the redox reaction in the Li−S battery is complicated and its mechanism is still not sufficiently understood.…”

Review of Graphene in Cathode Materials for Lithium-Ion Batteries

“…In recent years, the industrial application of carbon nanotubes in the field of lithium-ion batteries has been booming. − The main purpose of carbon nanotubes is to replace the conductive medium carbon black and improve the conductivity of cathode materials. As a result of its high conductivity and special one-dimensional (1D) tubular structure, carbon nanotubes effectively establish a conductive network connecting the positive material particles through a 1D bridge, which has obvious advantages over the point-to-point contact of traditional conductive medium carbon black. , The new graphene has the same structural unit as carbon nanotubes and has the same excellent conductivity. At the same time, the 2D planar structure makes it possible to form point-to-surface contact with the positive material particles.…”