Complete encapsulation of sulfur through interfacial energy control of sulfur solutions for high-performance Li−S batteries

Abstract

Complete encapsulation of high-content sulfur in porous carbon is crucial for high performance Li−S batteries. To this end, unlike conventional approaches to control the pore of carbon hosts, we demonstrate controlling the interfacial energy of the solution in the process of penetrating the sulfur-dissolved solution. We unveil, experimentally and theoretically, that the interfacial energy with the carbon surface of the sulfur solution is the key to driving complete encapsulation of sulfur. In the infiltration of sulfur solutions withN-methyl-2-pyrrolidone, we achieve complete encapsulation of sulfur, even up to 85 wt %. The sulfur fully encapsulated cathode achieves markedly high volumetric capacity and stable cycle operation in its Li−S battery applications. We achieve a volumetric capacity of 855 mAh/cm3at 0.2C and a capacity reduction of 0.071% per cycle up to 300 cycles at 1C.

Mesoporous Materials for Electrochemical Energy Storage and Conversion

“…An effective approach is to utilize ordered mesoporous carbon (OMC) as a sulfur host to provide a reservoir that traps polysulfides, to suppress the dissolution of active materials into the electrolyte and to facilitate the Li‐ion diffusion. [ 41,42 ] Based on this principle, a number of mesoporous carbons have been fabricated to promote the electrochemical performance of sulfur cathodes. [ 43 ] Ordered mesoporous carbons (carbons mesostructured from Korea, CMK‐3) with conductive polymers coating have been used as the conducting host for sulfur.…”

High energy density and extremely stable supercapacitors based on carbon aerogels with 100% capacitance retention up to 65,000 cycles

“…2A is the Raman spectra of sample TC-900, ZBC-900, and ZBTC 0.8 -900. They have two peaks at 1,343 and 1,580 cm −1 , representing the defects (sp 3 -C, D band) (39) and graphitization (sp 2 -C, G band) (40), respectively. The intensity ratios (I D /I G ) for sample TC-900, ZBC-900, and ZBTC 0.8 -900 are ca.…”

CoNiO2/Co4N Heterostructure Nanowires Assisted Polysulfide Reaction Kinetics for Improved Lithium–Sulfur Batteries

“…The process of loading sulfur was similar to the CS 2 dissolution method in the literature. [ 6 ] As‐obtained CoNiO 2 /Co 4 N–G composite was wetted with sulfur solution (CS 2 / N ‐methy‐pyrrolidinone (NMP), 1:1) and dried at 50 °C for 12 h. Note that the content of sulfur in this compound was controlled at 67%. For comparison experiments, other composite cathodes (such as CoNiO 2 –G–S, Co 4 N–G–S) were prepared by the same process.…”

“…Dispersing active sulfur into porous carbon matrix to form composite cathode is one of the main strategies. [ 6 , 7 , 8 ] Among the carbon based materials, graphene has attracted extensive attention. Its excellent conductivity and large specific surface area are used as electronic network to reduce the sulfur interface resistance and physical barrier to inhibit the diffusion of polysulfides, respectively.…”