Metal–Organic Framework–Based CoS2 Nitrogen‐Doped Carbon for High‐Performance Lithium Storage

Due to their large theoretical capacity, transition metal sulfides are regarded as ideal anode materials for lithium‐ion batteries (LIBs). However, a number of technical challenges and scientific issues, such as low utilization of active materials and large volumetric expansion, must be addressed before it can be used in practice. Herein, CoS 2 ‐embedded N‐doped carbon polyhedrons are constructed successfully and employed as an efficient anode of LIB. After 200 cycles at a current density of 0.2 Ag −1 , the optimal CoS 2 @NC‐400 demonstrates a high reversible capacity of 866.2 mAhg −1 , and after 500 cycles at a current density of 0.5 Ag −1 , there is no discernible capacity fading. The excellent electrochemical performance of CoS 2 @NC‐400 can be attributed to that graphitic N‐doped porous carbon provides a highly conductive framework, which facilitates electron transports and lessens the volume expansion of electrode during charging and discharging. Furthermore, the pyrrolic N‐doped carbon in the CoS 2 @NC‐400 composite allows for a lower diffusion barrier for Li‐ions in the electrode.