A Samarium-Doped Carbon Aerogel Cathode with Anchored Polysulfides for Lithium-Sulfur Batteries with High Electrochemical Performance: A Metal-Organic Framework Template Method.

A samarium-doped carbon aerogel cathode (CA-Sm) for high-performance lithium-sulfur batteries was successfully synthesized from a Sm-containing metal-organic framework (MOF) as a template through a sol-gel reaction and a carbonization process. Sm-MOF doping plays an important role in regulating the structure of the gel and promoting the formation of samarium oxide in an amorphous state that is uniformly dispersed among the carbon spheres. A CA/S/Sm electrode delivers an initial discharge capacity of 1322 mAh g-1 at a rate of 0.2 C. Furthermore, it possesses an initial discharge capacity of 1212 mAh g-1 at 0.5 C and still maintains a value of 866 mAh g-1 after 300 cycles. Both the anchoring of polysulfides to uniformly doped Sm and the influence of the Sm-MOF on the CA structure lead to the excellent performance of the battery, and effectively prevent polysulfides escaping from cathode, while suppressing the shuttle effect and enhancing the utilization of sulfur.