Abstract
Low electrical conductivity severely limits the application of Fe2O3 in lithium- and sodium-ion batteries. In respect of this, we design and fabricate Fe2O3/Fe3O4 nano-aggregates anchored on nitrogen-doped graphene as an anode for sodium-ion batteries with the assistance of microwave plasma. The highly conductive Fe3O4 in the composite can function as a highway of electron transport, and the voids and phase boundaries in the Fe2O3/Fe3O4 heterostructure facilitate Na+ ion diffusion into the nano-aggregates. Furthermore, the Fe–O–C bonds between the nano-aggregates and graphene not only stabilize the structural integrity, but also enhance the charge transfer. Consequently, the Fe2O3/Fe3O4/NG anode exhibits specific capacity up to 362 mAh g−1 at 100 mA g−1, excellent rate capability, and stable long-term cycling performance. This multi-component-based heterostructure design can be used in anode materials for lithium- and sodium-ion batteries, and potential opens a new path for energy storage electrodes.
Highlights
Insufficient lithium resources will seriously threaten the availability of future lithium-ion batteries (LIB)
The graphene oxide (GO) used in this work was produced from natural graphite flakes (Acros, Geel, Belgium) by a modified Hummer’s method [21]
The outstanding sodium storage properties of the Fe2O3/Fe3O4/NG can be attributed to its unique structural features, as illustrEatledctrinodSechemeR2s. (FΩir)st,Rthcte(Ωhi)ghlDyNcaond(cumct2isv−e1)Fe3O4 improves electron transport in the hybrid Fe2OF3/eF2eO33O/N4 Gnano-aggr6egates.21S0e.c6ond, t1h.e65ph×a1s0e−1b2oundaries and voids in the Fe2O3/Fe3O4 heterostructuFree2Op3r/oFvei3dOe4/fNasGt diffu8s.i9on cha1n3n4e.7ls for N1.a3+4 ×io1n0s−.11Third, the robust interfacial interaction reinforced by Fe–O–C bonds can maintain the integrity of the electrode during t4h. eDliosncgu-stseiromn cycles, and provide a highway for electron transfer between the graphene and the
Summary
Insufficient lithium resources will seriously threaten the availability of future lithium-ion batteries (LIB). Common strategies are to design nanosized iron oxide, and to use conductive additives, such as graphene [9,12,13] Another iron-based oxide, Fe3O4, has a slightly lower specific capacity (926 mAh g−1) and much higher electrical conductivity (102~103 S cm−1) than Fe2O3 [14]. Α-Fe2O3/Fe3O4 composite, Fe2O3/Fe3O4/FeCO3 composite, and porous Fe2O3/Fe3O4@carbon have been applied in LIBs and exhibited improved electrochemical performance in comparison with the Fe2O3 electrodes [18,19,20]. In these studies, the Fe3O4 plays the role of electron transport pathway, while the porous structure can facilitate fast ion transport. It is even claimed that the hetero-interfaces between the oxide components may provide an enhanced inner electric field which can assist the electron transfer and Li+ diffusion [19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
