Engineering capacitive contribution in dual carbon-confined Fe3O4 nanoparticle enabling superior Li+ storage capability

Iron oxides have attracted widespread attention as lithium-ion batteries anode in virtue of abundant resources, high theoretical capacity, and environmental friendliness. However, during the process of charging and discharging, the poor conductivity and large volume expansion of iron oxides lead to the pulverization of the material as well as the rapid capacity fading, which limits further application significantly. Hence, tiny Fe 3 O 4 nanoparticles encapsulated into double layers N -doped hollow carbon nanotubes (NHCNT/Fe 3 O 4 ) are synthesized by a controllable chemical bath deposition and subsequent carbonization treatment. Benefitting from the double carbon buffer layers and the outstanding N -doped carbon conductive network, the well-designed NHCNT/Fe 3 O 4 electrode delivers an excellent cycling stability with 87% capacity retention at 1 A g −1 after 1000 cycles and a remarkable rate performance. And hollow N -doped carbon nanotubes (NHCNT) displays a favorable reversible capacity of 350 mAh g −1 in the 500th cycle at 1 A g −1 . The in-depth kinetic analysis reveals the dominated capacitive contribution facilitate to realize a superior rate capability of NHCNT/Fe 3 O 4 anode. The excellent electrochemical performance exhibited by the NHCNT/Fe 3 O 4 composites material provides great innovative ideas and inspiration for the design of the next-generation lithium-ion battery anode materials.