Dual‐Function, Tunable, Nitrogen‐Doped Carbon for High‐Performance Li Metal–Sulfur Full Cell

Abstract

Lithium metal–sulfur (Li–S) batteries are attracting broad interest because of their high capacity. However, the batteries experience the polysulfide shuttle effect in cathode and dendrite growth in the Li metal anode. Herein, a bifunctional and tunable mesoporous carbon sphere (MCS) that simultaneously boosts the performance of the sulfur cathode and the Li anode is designed. The MCS homogenizes the flux of Li ions and inhibits the growth of Li dendrites due to its honeycomb structure with high surface area and abundance of nitrogen sites. The Li@MCS cell exhibits a small overpotential of 29 mV and long cycling performance of 350 h under the current density of 1 mA cm‐2. Upon covering one layer of amorphous carbon on the MCS (CMCS), an individual carbon cage is able to encapsulate sulfur inside and reduce the polysulfide shuttle, which improves the cycling stability of the Li–S battery. As a result, the S@CMCS has a maximum capacity of 411 mAh g‐1 for 200 cycles at a current density of 3350 mA g‐1. Based on the excellent performance, the full Li–S cell assembled with Li@MCS anode and S@CMCS cathode shows much higher capacity than a cell assembled with Li@Cu anode and S@CMCS cathode.

Advanced Anode Materials of Potassium Ion Batteries: from Zero Dimension to Three Dimensions

“…Furthermore, the unwanted K-metal deposition on the surface of anode may be hindered due to the insertion potential versus K + /K of K-ion (0.2 V), which is beneficial for improving safety in terms of operation [ 32 ]. Moreover, compared with Li metal (180.54 °C) and Na metal (≈ 98 °C), K-metal lower melting point (63.38 °C) makes the dendritic K melting to provide a secure capability under an appropriate temperature [ 10 , 36 , 37 ]. It is worth mentioning that Cu foil can be replaced with Al foil as current collectors in anode electrode of PIBs without forming Al-K alloy, cutting down the batteries’ production expenses [ 29 ].…”

Nb2O5/RGO Nanocomposite Modified Separators with Robust Polysulfide Traps and Catalytic Centers for Boosting Performance of Lithium–Sulfur Batteries

“…Improving the areal loading of sulfur is very important for high‐energy‐density LSBs . As shown in Figure d,e, the battery with the areal sulfur loading of 2.0 mg cm −2 achieves a reversible capacity of 584 mAh g −1 after 400 cycles at 1.0 A g −1 (corresponding to a capacity retention of 76%).…”

Hierarchical porous N,S‐codoped carbon material derived from halogenated polymer for battery applications

“…To load S in NS‐C host, the NS‐C was mixed with powder S (inset of Figure 3A) at a weight ratio of four to six, followed by the mixture treated at 155°C for 12 hours. As indicated by the XRD profile (Figure 3A), the S@NS‐C composite exhibits no obvious crystalline peaks for S compared to the sharp XRD peaks of elemental sulfur, suggesting the full occupation of micropores and small‐sized mesopores of NS‐C by S. [ 44,45 ] The capability of trapping Li polysulfide (Li‐PS) of NS‐C was examined using an ex‐situ adsorption test (Figure 3B). The color of the Li 2 S 6 /electrolyte notably changes from dark yellow to colorless in 2 hours by adding NS‐C (inset of Figure 3B), suggesting that the heavy co‐doping in NS‐C enables efficient trapping of Li‐PS.…”