Figure 2. In situ compression experiment on a single porous carbon sphere with macroporous structure.

(a–f) TEM images of a single carbon sphere under the deformation with different loading times (insert white arrow indicates the loading direction). The first crack occurred at t = 170 s and propagated to a sudden failure of the whole carbon sphere with the appearance of more cracks and collapse of pores at 310 s (black arrows point out the position of main cracks). Most pores inside the carbon sphere failed and densified at t = 420 s. (g) Applied displacement loading and resulting force curves with compression time concurring with the above deformation process.