Lithium manganate, LiMn2O4, powders with different crystallinity were prepared through Lithium-manganese-oxalates and -tartrates. The capacity of the plateau at around 4 V increased linearly with the increase of the lattice parameter a(0) and the decrease of lattice strain epsilon, which seemed to be due to the annealing of the imperfection of cation distribution in the spinel structure and the decrease of the mean oxidation state of manganese ions, on all samples in four series. On the other hand, the decrease of capacity of the plateau at around 3 V of the host was governed by the precursor dicarboxylates used; independent of the crystallinity in LiMn2O4 via tartrates, but strongly dependent in those via oxalates.