Chitosan-derived graphitic carbon@Fe3C as anode materials for lithium ion battery.

Chitosan-based carbon materials have attracted great attention in electrochemical energy storage. Introducing iron metal or iron compounds into carbon materials favors to boost their electrochemical performance. Herein, chitosan-based graphitic carbon@Fe₃C composites (CSGC@Fe₃C) have been prepared as anode materials for lithium ion battery by a simple pyrolysis method. By manipulating the temperature higher than 700 °C, pure Fe₃C encapsulated in chitosan-based graphitic carbon with different mass ratio from 30 to 53.8 wt% can be achieved. The resulting CSGC@Fe₃C composites retain porous carbon sheet structure embedded with a large amount of Fe₃C nanoparticles in size from 20 to 300 nm. The electrochemical measurements demonstrate CSGC@Fe₃C with 53.8 wt% Fe₃C as anode material for lithium ion battery can provide a highest reversible capacity of 423 mAh g⁻¹ at 0.1 A g⁻¹ over 100 charge/discharge cycles and stable cycling capacity of 195 mAh g⁻¹ at a high current density of 2 A g⁻¹ during 200 cycles. The catalysis of Fe₃C on the reversible formation and decomposition of solid electrolyte interphase (SEI) has been corroborated and results in the improvement of surface capacitive contribution. This work provides a basic insight into metal carbides constructing biomass-based carbon anode materials to realize high-performance electrochemical energy storage device. [ABSTRACT FROM AUTHOR]