g-C₃N₄/g-C₃N₄ Heterojunction as the Sulfur Host for Enhanced Cyclic Stability of Li–S Batteries

Abstract

Li−S batteries are recognized as one of the most promising energy storage and conversion devices because of the high theoretical energy density and acceptable financial and environmental costs but suffer from sluggish sulfur reduction. Herein, the g-C 3 N 4 /g-C 3 N 4 heterojunction is synthesized using two kinds of precursors, aiming to adjust the electron cloud structure of g-C 3 N 4 and the interface adhesion energy. This intimate interface of g-C 3 N 4 /g-C 3 N 4 endows a significantly accelerated reaction kinetics and enhanced transportation of ions and electrons. Furthermore, the abundant N element of g-C 3 N 4 allows physical confinement and chemical interactions with lithium polysulfides (LiPSs). As a result, a Li−S cell with a g-C 3 N 4 /g-C 3 N 4 heterojunction as the sulfur host provides an initial discharge capacity of 1200 mAh/g at 0.1 C and retains 464 mAh/g after 150 cycles at 1 C. It also exhibits a stable rate capability of 350 mAh/g after 500 cycles at 2 C. This study may provide insights into functionalizing g-C 3 N 4 for application in Li−S batteries.

The Metal–Organic Frameworks Derived Co3O4/TiO2 Heterojunction as a High‐Efficiency Sulfur Carrier for Lithium–Sulfur Batteries

“…Figure 15 compares the different electrode performances of this study with previous reports, and it can be seen that the S@Co 3 O 4 /TiO 2 cathode has excellent electrochemical performance with high capacity retention at 1C, indicating that the shuttle effect and other problems are effectively mitigated and the S cathode performance is improved. [25,[59][60][61][62][63][64]…”

V-doped Ni2P nanoparticle grafted g-C3N4 nanosheets for enhanced photocatalytic hydrogen evolution performance under visible light

“…Pure g-C 3 N 4 appears to exhibit the typical characteristic peaks, and the peak at 807 cm −1 corresponds to the intrinsic bending vibration of tri-s-triazine ring units, while the peaks at 1637 cm −1 and 1243 cm −1 originate from the -C-N and -CvN stretching vibration modes of g-C 3 N 4 , respectively. 53 And the weak peaks from 2900 cm −1 to 3340 cm −1 are related to the residual N-H bond stretching vibration modes of NH 2 S4(a and b) † that the NiV-LDH nanosheets consisted of polycrystals. The V-Ni 2 P sample still maintains a similar nanoflower structure, as shown in Fig.…”

A carbon quantum dot-decorated g-C3N4 composite as a sulfur hosting material for lithium–sulfur batteries

“…23 Great efforts have been devoted to making g-C 3 N 4 more useful in Li-S batteries, including the introduction of dielectric structures, nanostructure engineering, semiconductor recombination metal coating, and element doping. [24][25][26][27][28] Zero-dimensional (0D) carbon "quantum" dots or carbon dots (CQDs), a new member of the carbon-based nanomaterials with various surface passivation schemes, have recently been the focus of considerable scientific attention due to their unique and excellent physical and chemical properties. [29][30][31] Numerous CQDs have been developed and applied widely in photoluminescence, 32,33 cell imaging, 34 and solar cells.…”

“…23 Great efforts have been devoted to making g-C 3 N 4 more useful in Li–S batteries, including the introduction of dielectric structures, nanostructure engineering, semiconductor recombination metal coating, and element doping. 24–28…”