Fabrication of ultrafine Gd₂O₃nanoparticles/carbon aerogel composite as immobilization host for cathode for lithium‐sulfur batteries

Abstract

Summary Carbon aerogel (CA), possessing abundant pore structures and excellent electrical conductivity, have been utilized as conductive sulfur hosts for lithium‐sulfur (Li‐S) batteries. However, a serious shuttle effect resulted from polysulfide ions has not been effectively suppressed yet due to the weak absorption nature of CA, resulting in rapid decay of capacity as the cycle number increases. Herein, ultrafine (~3 nm) gadolinium oxide (Gd2O3) nanoparticles (with upper redox potential of ~ 1.58 V versus Li+/Li) are uniformly in‐situ integrated with CA through directly sol‐gel polymerization and high‐temperature carbonization. The Gd2O3 modified CA composites (named as Gdx‐CA, where x means molar ratio of Gd2O3 nanoparticles to carbon) are incorporated with S. Then, the products (S/Gdx‐CA) are acted as sulfur host materials for Li‐S batteries. The results demonstrate that adding ultrafine Gd2O3 nanoparticles can dramatically improve the electrochemical properties of the composite cathodes. The S/Gd2‐CA electrode (loading with 58.9 wt% of S) possesses the best electrochemical properties, including a high initial capacity of 1210 mAh g−1 and a relatively high capacity of 555 mAh g−1 after 50 cycles at 0.1 C. It is noteworthy that the performance of long‐term cycle (350 cycles) for the S/Gd2‐CA (317 mAh g−1 after 100 cycles and 233 mAh g−1 after 350 cycles at 1 C) is improved significantly than that of S/CA (150 mAh g−1 after 150 cycles at 1 C). Overall, the enhancement of electrochemical performances can be due to the strong polar nature of the ultrafine Gd2O3 nanoparticles, which provide strong adsorption sites to immobilize S and polysulfide. Furthermore, the Gd2O3 nanoparticles present a catalytic effect. Our research suggests that adding Gd2O3 nanoparticles into S/CA composite cathode is an effective and novelty method for improving the electrochemical performances of Li‐S batteries.

Freestanding graphitic carbon nitride‐based carbon nanotubes hybrid membrane as electrode for lithium/polysulfides batteries

“…In addition, functionalizing the separator or interlayers has been shown to provide a polysulfide shuttle barrier and improve electron transport, but they also bring extra weight and reduce the overall energy density. Recently, the introductions of polar inorganic compounds into carbon‐based materials, such as metal oxides, metal sulfides, metal nitrides, and metal carbides have also been extensively investigated to bond with polysulfides species.…”

Synergistic effect of titanium‐oxide integrated with graphitic nitride hybrid for enhanced electrochemical performance in lithium‐sulfur batteries

“…The D Li+ values according to Equations S3 and S4 are 2.3 × 10 −7 cm 2 s −1 and 6.4 × 10 −9 cm 2 s −1 for TOCN@S and CN@S composite electrodes, which further proved as above results. [58][59][60] Such a facile synthesis strategy provided for environmental-friendly and resourcesaving approach for easy and large-scale preparation of CN-based composites for modification sulfur cathode, which demonstrated more development of high energy density and durable Li-S batteries.…”

The Application of Indium Oxide@CPM-5-C-600 Composite Material Derived from MOF in Cathode Material of Lithium Sulfur Batteries

“…In addition to the presence of carbon, we found the indium and oxygen elements were distributed on the surface of CPM-5-C-600 uniformly after the EDS analysis and test. We didn't choose to wash off the metal oxides on the surface with strong acid or alkali, because we supposed that the existence of metal oxides would form a specific core-shell structure with CPM-5-C-600 [24]. Therefore, the composite material will not only enhance the conductivity of the material and improve the rate performance of the battery, but also inhibit the intermediate product polysulfide, which will decrease the decay rate of polysulfide and promote the cycle stability of the battery [25].…”