A Polysulfide-Infiltrated Carbon Cloth Cathode for High-Performance Flexible Lithium–Sulfur Batteries

Abstract

For practical application of lithium–sulfur batteries (LSBs), it is crucial to develop sulfur cathodes with high areal capacity and cycle stability in a simple and inexpensive manner. In this study, a carbon cloth infiltrated with a sulfur-containing electrolyte solution (CC-S) was utilized as an additive-free, flexible, high-sulfur-loading cathode. A freestanding carbon cloth performed double duty as a current collector and a sulfur-supporting/trapping material. The active material in the form of Li2S6 dissolved in a 1 M LiTFSI-DOL/DME solution was simply infiltrated into the carbon cloth (CC) during cell fabrication, and its optimal loading amount was found to be in a range between 2 and 10 mg/cm2 via electrochemical characterization. It was found that the interwoven carbon microfibers retained structural integrity against volume expansion/contraction and that the embedded uniform micropores enabled a high loading and an efficient trapping of sulfur species during cycling. The LSB coin cell employing the CC-S electrode with an areal sulfur loading of 6 mg/cm2 exhibited a high areal capacity of 4.3 and 3.2 mAh/cm2 at C/10 for 145 cycles and C/3 for 200 cycles, respectively, with minor capacity loss (<0.03%/cycle). More importantly, such high performance could also be realized in flexible pouch cells with dimensions of 2 cm × 6 cm before and after 300 bending cycles. Simple and inexpensive preparation of sulfur cathodes using CC-S electrodes, therefore, has great potential for the manufacture of high-performance flexible LSBs.

Microporous Carbon Nanoparticles for Lithium–Sulfur Batteries

“…Significantly, one of the most important aspects is the high areal capacity of LSBs comparable to that of the LIBs (4 mAh cm −2 ). High-loading sulfur is essential for rival LIBs [ 17 ]. The powder X-ray diffraction (XRD) patterns of sulfur, sulfur in CS 2 , and the GL-I-800+S composite are displayed in Figure 3 c. After loading the sulfur into the GL-I-800 host materials, the XRD patterns of the resultant GL-I-800+S composite reveal that the elemental sulfur of S 8 is well maintained during the preparation of the electrode.…”

“…An effective strategy consists of confining the polysulfides on a cathode structure to improve performance by reducing the diffusion of dissolution products on the anode. Encompassing conductive additives, porous supporting materials on active materials bolster the sulfur’s electronic and ionic conductivity [ 16 , 17 ]. Additionally, the low solubility of the polymer/solid electrolyte for polysulfides to attenuate the dissolution from cathode materials has been introduced [ 18 ].…”

“…Additionally, the low solubility of the polymer/solid electrolyte for polysulfides to attenuate the dissolution from cathode materials has been introduced [ 18 ]. The use of additive materials to encapsulate the anode metal’s active surface to safeguard against Li 2 S passivation has been considered [ 17 ]. Different research attempts have presented different strategies to mitigate these challenges.…”

MIL-88A Metal-Organic Framework as a Stable Sulfur-Host Cathode for Long-Cycle Li-S Batteries

“…The positive electrodes were prepared by doctor blade casting of a slurry formed by the MIL-88A@S composite (70 wt.%), carbon black (20 wt.%) as a conducting agent, and PVDF (10 wt.%) as a binder in 0.8 mL of N-methyl-2-pyrrolidone on a GDL foil. GDL carbon cloth has proven to be an effective current collector in cathodes of Li-S cells [60,61]. The electrode was dried at 80 • C on a heating plate for 3 h and cut into discs of 13-mm diameter with a sulfur loading between 1.0-1.5 mg cm −2 .…”

Electrospun 3D Structured Carbon Current Collector for Li/S Batteries

“…Carbon materials are a promising alternative to conventional metal-based current collectors due to their good chemical/electrochemical stability and low density, which reduces the total weight of a cell and increases its overall gravimetric energy density. A variety of carbon current collectors such as carbon paper, graphite sheets, three-dimensional (3D) carbon foam, carbon fiber mats with high specific surface areas have been applied to improve cycle life and gravimetric energy density of electrode materials [15][16][17][18][19][20]. Particularly, carbon fibers (CFs) have many advantages like high conductivity, structural stability and large surface area to accommodate more electrode materials, which makes them attractive to use in energy storage devices [21,22].…”