fig2

Figure 2. (A) Schematic diagram of the preparation process of MFe₂O₃@N-HCNs; (B) SEM, (C) TEM, and (D) HRTEM images of MFe₂O₃@N-HCNs. (E) Rate capabilities of N-HCNs, MFe₂O₃, and MFe₂O₃@N-HCNs anodes from 0.1 to 2 A g^-1; (F) Cycling performance of N-HCNs, MFe₂O₃, and MFe₂O₃@N-HCNs at 0.1 A g^-1[20]. Copyright 2021, American Chemical Society.