HIERARCHICALLY NANOSTRUCTURE ELECTRODE MATERIALS FOR LITHIUM-ION BATTERIES - Electrochemical Nanofabrication: Principles and Applications - page 253

Fig 6.4c that even in case of the formation of Li Sn, there still

exists enough free space (about 17% of the total space) in the
hollow carbon spheres. Consequently, this type of Sn-based
nanocomposites have an extremely high specific capacity of larger
than 800 mAh g

4.4

- 1

in the first 10 cycles, and ca. 550 mAh g

- 1

even

after 100 cycles.

(a) TEM image of TNHCs. Inset shows a close view of a single
broken carbon spherical shell studded with tin particles. (b) SEM image of
TNHCs. (c) Sketch of the lithiation and delithiation process of TNHCs (all
reproduced with permission from [30], copyright 2008, Wiley-VCH Verlag
GmbH & Co. KGaA).

Figure 6.4

Other sphere-like hierarchical structured materials include
mesoporous microspheres [55]. It has been reported that mesoporous
anatase TiO
2

sub-micrometer spheres, including mesoporous TiO
2

spheres that have an average particle size of 300 nm and a pore size
in the range of 3-30 nm (as shown in Fig 6.5a), seem to be more
promising for anode materials of lithium-ion batteries [64, 65]. They