Plasma Enabled FeO/FeO Nano-aggregates Anchored on Nitrogen-doped Graphene as Anode for Sodium-Ion Batteries.

Low electrical conductivity severely limits the application of FeO in lithium- and sodium-ion batteries. In respect of this, we design and fabricate FeO/FeO nano-aggregates anchored on nitrogen-doped graphene as an anode for sodium-ion batteries with the assistance of microwave plasma. The highly conductive FeO in the composite can function as a highway of electron transport, and the voids and phase boundaries in the FeO/FeO 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 FeO/FeO/NG anode exhibits specific capacity up to 362 mAh g at 100 mA g, 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.