
201Layer-Structured Cathode Materials forEnergy Storage
or solid solution in the form of layered–layered integrated xLi
2
M’O
3
⋅ (1 − x)
LiMO
2
or layered–spinel-integrated xLi
2
M’O
3
⋅ (1 − x)LiM
2
O
4
, where M′ can be
manganese, chromium and titanium; M indicates the commonly used transi-
tion metals, and x is the molar ratio between the two compounds [26]. The
manganese-involved xLi
2
MnO
3
⋅ (1 − x)LiMO
2
structures show more advan-
tages than other systems since the component Li
2
MnO
3
itself is electrochemi-
cally active as a cathode material [49], while others such as Li
2
ZrO
3
and Li
2
TiO
3
are electrochemically inactive as electrode materials. Usually