A 3d Hierarchical Structured Pyrolyzed Bacterial Cellulose Matrix Fe2o3/Fe3n Nanoparticles Encapsulated in Carbon Nanotubes (Pbc@Fe2o3/Fe3n-Cnt) Toward Ultrahigh Potassium/Sodium Storage Performance

Iron nitride is a promising anode material with ultrahigh theoretical capacity and excellent electrical conductivity. Nevertheless, due to the poor stability of metal nitrides on account of their amorphous and powdering in the long-term charging and discharging process, their electrochemical performance is limited. Herein, we develop a simple method to synthesize the 3D hierarchical architecture of 0D Fe 3 N and Fe 2 O 3 nanoparticles encapsulated in 1D carbon nanotubes (CNTs) grafted 2D pyrolyzed bacterial cellulose (PBC) carbon matrix (denoted as PBC@Fe 2 O 3 /Fe 3 N-CNT) as advanced anode materials for potassium-ion batteries (PIBs), which has a high reversible capacity of 342.2 mAh g -1 at 100 mA g -1 and a superior rate capability of 330.1 mAh g -1 at 3200 mA g -1 , exceeding most of the reported anode materials. In addition, the PBC@Fe 2 O 3 /Fe 3 N-CNT electrode can maintain a high reversible capacity of 280.4 mAh g -1 after 1000 cycles at a high current density of 400 mA g -1 . Further, in order to prove the universality of the PBC@Fe 2 O 3 /Fe 3 N-CNT, we applied it to the sodium-ion batteries (SIBs) and it also showed excellent electrochemical performance