A new concept of an elemental iron-based sodium ion battery of PC–Fe3O4/Na2FeP2O7 was reported, and it is the first example to introduce an element-rich configuration in the sodium ion battery from the viewpoint of sustainability.
Nitrogen and oxygen co-doped porous carbon network is synthesized by NaCl template-assisted in situ confinement method and used for a high-performance sodium-ion battery anode.