An Active Amorphous Carbon Material with Fe2C Nanocrystals Encapsulated as a High Performance Electrode for Lithium-Ion Batteries

摘要

A nitrogen and sulfur dual doped carbon with Fe2C nanocrystals encapsulated material (Fe2C@C) was synthesized by a simultaneous polymerization-precipitation technique followed with a high temperature pyrolysis process. This method can lead to an effective and homogenous distribution of core/shell Fe2C /carbon nanoparticles into the carbon matrix. The optimized material was applied as an anode for a lithium-ion battery, which showed a high capacity, excellent rate performance, and good cycling capability. It delivered a high specific capacity of 657.7 mA h g~(-1) at a current density of 0.2 A g~(-1), and even at a very high current density of 6 A g~(-1), the electrode still retained a very high specific capacity of 509.1 mA h g~(-1). After 150 cycles of charge/discharge at a current density of 1 A g~(-1), no capacity decay was observed which presents itself a promising high performance anode for LIBs. It may be ascribed to that the presence of Fe2C can greatly stabilize the structure of the electrode and the electrode process for the lithiation/ delithiation of LIBs.