Performance Study of MXene/Carbon Nanotube Composites for Current Collector‐ and Binder‐Free Mg–S Batteries

Abstract

The realization of sustainable and cheap Mg‐S batteries depends on significant improvements in cycling stability. Building on the immense research on cathode optimization from Li‐S batteries, for the first time a beneficial role of MXenes for Mg‐S batteries is reported. Through a facile, low‐temperature vacuum‐filtration technique, several novel current collector‐ and binder‐free cathode films were developed, with either dipenthamethylene thiuram tetrasulfide (PMTT) or S8 nanoparticles as the source of redox‐active sulfur. The importance of combining MXene with a high surface area co‐host material, such as carbon nanotubes, was demonstrated. A positive effect of MXenes on the average voltage and reduced self‐discharge was also discovered. Ascribed to the rich polar surface chemistry of Ti3C2Tx MXene, an almost doubling of the discharge capacity (530 vs. 290 mA h g−1) was achieved by using MXene as a polysulfide‐confining interlayer, obtaining a capacity retention of 83 % after 25 cycles.

Dual Role of Mo6S8 in Polysulfide Conversion and Shuttle for Mg–S Batteries

“…It is noteworthy to mention that the sulfur loading of the cathode material is higher than those of the reported Mg–S batteries. [ 8 , 12 , 15 ] Besides, SEM/EDS analysis of the morphology and element distribution of the cathode material manifests that sulfur was uniformly dispersed within the carbon host material (Figure S9c–e , Supporting Information).…”

Rational Design Strategy of Novel Energy Storage Systems: Toward High‐Performance Rechargeable Magnesium Batteries

“…Taking account of the mature techniques to increase the sulfur usage in LiS batteries, they are still suitable to MgS batteries to improve the cycling performance, such as reinforcing the contact between elemental sulfur and carbon substrate and adopting organic sulfide substitution. Besides, many catalysts accelerating reaction kinetics in LiS batteries [104,[119][120][121][122][123] would also be adopted to MgS batteries for high rate performance.…”

Atomic surface modification strategy ofMXenematerials forhigh‐performancemetal sulfur batteries

“…(A) Procedure for preparing PMTT composites from Ti 3 C 2 T x MXene, CNT, and PMTT; Cycling stability and voltage profiles for the first and 10th cycle. Reproduced by permission 124 . Copyright 2021, WILEY‐VCH.…”

“…Based on the synergistic effect of MXenes and CNTs, Wagner et al used low‐temperature vacuum filtration technology to prepare MXenes/CNTs composites (Figure 9A). 124 Due to the rich surface chemistry of MXene, polysulfide‐limited dissolution achieves nearly doubled discharge capacity (530 vs 290 mAh g −1 ), achieving 83% capacity after 25 cycles retention rate (Figure 9A). 124 Meanwhile, the Co 3 S 4 @MXene heterostructure can well absorb and catalyze the conversion of polysulfides, resulting in improved electrochemical redox kinetics, exhibiting high S utilization, a specific capacity of 1220 mAh g −1 and a The retention capacity is 528 mAh g −1 cycle (Figure 9B).…”