Mace-like carbon fibers@Fe3O4@carbon composites as anode materials for lithium-ion batteries

Mace-like carbon fibers@Fe 3 O 4 @carbon (CF@Fe 3 O 4 @C) composites were designed and synthesized via an in situ growth and carbon coating approach with heat treatment. In comparison with CF, Fe 2 O 3 , and CF@Fe 2 O 3 , CF@Fe 3 O 4 @C composites exhibit higher electrochemical performance as anode materials for lithium-ion batteries (LIBs), owing to the unique mace-like ordered structure. Mace-like CF@Fe 3 O 4 @C composites deliver a high discharge/charge specific capacities of 1368/940 mAh g −1 at the first cycle and 741/740 mAh g −1 at the 100th cycles at 100 mA g −1 in the range of 0.01~2.5 V. The specific discharge capacity can still retain 503 mAh g −1 after 500 cycles at 500 mA g −1 . The outstanding electrochemical performance can be attributed to that carbon fibers and carbon coating improve the electrical conductivity of iron oxides and the carbon-coated layer avoids the specific capacity fading caused by volume expansion of iron oxides during charging/discharging. It provides a novel structural design strategy and an effective synthesis method of anode material for high-energy lithium-ion battery.