Enhancement of ZIF-8 derived N-doped carbon/silicon composites for anode in lithium ions batteries

It is urgent to develop novel anode materials with high energy density and facile synthetic procedures, since the development of commercial lithium ions batteries (LIBs) is limited by the unsatisfied capacity of graphite. Herein, we propose a modified method to prepare core-shell structured ZIF-8 derived N-doped carbon/silicon (Si@NC) composites (6.6 wt% of nano-Si), featuring facile synthetic procedures and mild condition. The physicochemical properties of the ZIF-8 derived N-doped carbon are not changed when the nano-Si particles are employed as the seeds. The Si@NC composites deliver high reversible capacity of 724 mAh g −1 . Attributed to the good charge conductivity and structural stability of the ZIF-8 derived N-doped carbon, the Si@NC composites exhibit good rate performance (98.5% of the initial average capacity is retained after being cycled at different current density) and cycle stability (302 mAh g −1 while that of commercial graphite is ~10 mAh g −1 at 1000 mA g −1 after 800 cycles). The enhancement of lithium storage capability of the ZIF-8 derived N-doped carbon shows promising application in high energy density LIBs.