Figure 13
From: Hollow Nanostructured Anode Materials for Li-Ion Batteries
a Schematic presentation of the self-supported topotactic transformation process for formation of needle-like Co3O4 nanotubes; b low-magnification SEM image of Co3O4 nanotubes; c high-magnification SEM image of Co3O4 nanotubes, the inset shows a cross-sectional view of nanotubes; d TEM image of a single nanotube [51]. Copyright Wiley–VCH Verlag Gmbh & Co. KGaA. Reproduced with permission