Radially Inwardly Aligned Hierarchical Porous Carbon for Ultra‐Long‐Life Lithium–Sulfur Batteries

Abstract

Rational design of hollow micro‐ and/or nano‐structured cathodes as sulfur hosts has potential for high‐performance lithium‐sulfur batteries. However, their further commercial application is hindered because infusing sulfur into hollow hosts is hard to control and the interactions between high loading sulfur and electrolyte are poor. Herein, we designed hierarchical porous hollow carbon nanospheres with radially inwardly aligned supporting ribs to mitigate these problems. Such a structure could aid the sulfur infusion and maximize sulfur utilization owing to the well‐ordered pore channels. This highly organized internal carbon skeleton can also enhance the electronic conductivity. The hollow carbon nanospheres with further nitrogen‐doping as the sulfur host material exhibit good capacity and excellent cycling performance (0.044 % capacity degradation per each cycle for 1000 cycles).

Material design and structure optimization for rechargeable lithium-sulfur batteries

“…The porous carbon hosts can greatly enhance the electronic conductivity of sulfur electrodes, accommodate huge volume change of sulfur species, and immobilize soluble polysulfides. So far, various porous carbons with different dimensions, such as zero-dimensional (0D) hollow carbon spheres, [93][94][95][96][97][98] multi-shell carbon spheres, [99][100][101] hierarchical porous carbon spheres, [102][103][104][105] 1D carbon tubes and carbon fibers, [106][107][108][109][110] 2D graphene and carbon sheets, [111][112][113][114][115] and 3D carbon frameworks, [116][117][118] have been extensively investigated (Figure 4A). In a representative example, inspired by the structure of old-fashioned photo albums, the 2D yolk-shell carbon nanosheets were synthesized to construct a novel freestanding sulfur cathode with a high sulfur loading of 5 mg cm À2 and a high sulfur content of 73 wt %, which can deliver an areal capacity of 5.7 mAh cm À2 and a volumetric capacity of 1,330 mAh cm À3 .…”

Advanced TexSy-C Nanocomposites for High-Performance Lithium Ion Batteries

“…Lithium-tellurium (Li-Te) batteries have attracted increasing attention owing to their high theoretical volume capacity ( Liu et al, 2014 ; Ding et al, 2015 ; Li et al, 2017 ; Li G. et al, 2018 ; Yin et al, 2018 ; Wenjie Han et al, 2021 ), excellent electronic conductivity ( He et al, 2017 ), and relieved shuttle effects compared to Li-sulfur, Li-selenium batteries ( Yang et al, 2013 ; Eftekhari, 2017 ; Li Y. et al, 2018 ; Fan et al, 2019 ; Wang et al, 2020 ; Yu et al, 2020 ; Dai et al, 2021 ; Sun et al, 2021 ; Xiao et al, 2021 ). However, the huge volume expansion of Te severely deteriorates its practical applications towards the newly emerged battery systems.…”

Polypyrrole/Graphene Composite Interlayer: High Redox Kinetics of Polysulfides and Electrochemical Performance of Lithium–Sulfur Batteries Enabled by Unique Pyrrolic Nitrogen Sites

“…[28] It is very challenging to prepare well-defined carbon materials with only single type of these nitrogen species and exactly corroborate which kind of nitrogen species is responsible for the enhanced redox kinetics of PSs and the electrochemical performance of LiÀ S batteries experimentally, although plenty of theoretical based-calculations have been performed and indicate that pyrrolic nitrogen is superior to the other two kinds of nitrogen species. [29][30][31][32][33] It should be noted that organic polymers could be rationally designed to possess a single type of graphitic, pyridinic or pyrrolic nitrogen species, and behave as a good candidate for investigation of the roles of these specific doped-nitrogen atoms in the electrochemical conversion of PSs in LiÀ S batteries. [34][35][36][37] Herein, a multi-functional interlayer was made by embedding conductive polymerized pyrrole (PPy) into 2D ultrathin graphene layers (PPy/G) for LiÀ S batteries.…”