Durable Lithium–Sulfur Batteries Based on a Composite Carbon Nanotube Cathode

Abstract

Lithium–sulfur (Li–S) batteries (LSBs) have high energy densities and employ inexpensive materials. However, the poor sulfur conductivity and rapid capacity fading hamper their applications. We developed a free-standing composite cathode based on multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs), whose fabrication follows a solution-based, scalable method. The two CNT types create a synergic effect: SWCNTs result in high conductivity, high surface area, and mechanical strength/flexibility; MWCNTs’ larger pores ensure facile ionic diffusion and trapping of lithium polysulfides. The composite cathode exhibits a peak discharge capacity of 1221 mAh/g, maintaining 876 mAh/g after 100 cycles at a 0.1C rate.

What Is the Real Origin of Single-Walled Carbon Nanotubes for the Performance Enhancement of Si-Based Anodes?

“…The same trend is also shown for the electrical conductivity test in Figure d. Hence, although individual MWNTs are normally more rigid and conductive than individual SWNTs, , SWNTs can form stronger and more electrically conductive 3D networks than those constructed by MWNTs. This phenomenon can also be explained by the DFT calculations, which show that the binding energy (Figure e) and electron transfer (Figure S26) can be much improved for two contacted CNTs with tube deformation as compared to those when two CNTs are contacted with a rigid configuration.…”

“…In addition, SWNTs tend to form tightly bonded bundles, making them difficult to disperse. , Thus, SWNTs seem to offer no advantages over MWNTs in terms of conductivity or dispersion. In addition to these properties, one of the most distinctive features between SWNTs and MWNTs lies in their flexibility. , Considering the fact that large stresses can be generated during volume expansion in the lithiation process, pushing the active materials onto CNTs. Because SWNTs are much more flexible than MWNTs, this internal pressure could generate a much higher strain in SWNTs than in MWNTs.…”

Anisotropic carbon matrix derived from cellulose aerogel decorated wood plate serving as self- supporting hosts for cathodes in lithium sulfur batteries with enhanced cycling stability

“…To overcome these challenges, considerable efforts have been devoted to the rational design of S cathode by researchers. In particular, porous carbon materials with large speci c surface area, high conductivity, and stable chemical property have been widely used in S cathodes, such as carbon nanotube (CNT) (Yahalom et al 2023), reduced graphene oxide (RGO) (Kim et al 2023), and cellulose aerogel (CA) (Mao et al 2020), etc. Normally, the microstructure of conventional carbon matrix is open, causing electrolyte and LiPSs permeate through easily.…”

Recent advances in food waste-derived nanoporous carbon for energy storage

“…Efforts are being made to realize the commercialization of sodium-ion batteries (SIBs) [ 24–28 ]. Simultaneously, lithium-sulfur batteries (LSBs) have also made significant strides in development [ 29 ]. Moreover, recent research efforts have also been directed towards the commercialization of iron-ion, magnesium-ion, and aluminium-ion batteries [ 30–32 ].…”