Coated/Sandwiched rGO/CoS x Composites Derived from Metal–Organic Frameworks/GO as Advanced Anode Materials for Lithium‐Ion Batteries

Rational composite materials made from transition metal sulfides and reduced graphene oxide (rGO) are highly desirable for designing high‐performance lithium‐ion batteries (LIBs). Here, rGO‐coated or sandwiched CoS x composites are fabricated through facile thermal sulfurization of metal–organic framework/GO precursors. By scrupulously changing the proportion of Co 2+ and organic ligands and the solvent of the reaction system, we can tune the forms of GO as either a coating or a supporting layer. Upon testing as anode materials for LIBs, the as‐prepared CoS x ‐rGO‐CoS x and rGO@CoS x composites demonstrate brilliant electrochemical performances such as high initial specific capacities of 1248 and 1320 mA h g −1 , respectively, at a current density of 100 mA g −1 , and stable cycling abilities of 670 and 613 mA h g −1 , respectively, after 100 charge/discharge cycles, as well as superior rate capabilities. The excellent electrical conductivity and porous structure of the CoS x /rGO composites can promote Li + transfer and mitigate internal stress during the charge/discharge process, thus significantly improving the electrochemical performance of electrode materials.