Abstract
We demonstrate here that mesoporous tin dioxide (abbreviated M-SnO 2) with a broad pore size distribution can be a prospective anode in lithium-ion batteries. M-SnO 2 with pore size ranging between 2 and 7.5 nm was synthesized using a hydrothermal procedure involving two different surfactants of slightly different sizes, and characterized. The irreversible capacity loss that occurs during the first discharge and charge cycle is 890 mAh g -1, which is smaller than the 1,010-mAh g -1 loss recorded for mesoporous SnO 2 (abbreviated S-SnO 2) synthesized using a single surfactant. After 50 cycles, the discharge capacity of M-SnO 2 (504 mAh g -1) is higher than that of S-SnO 2 (401 mAh g -1) and solid nanoparticles of SnO 2 (abbreviated nano-SnO 2<4 mAh g -1) and nano-SnO 2. Transmission electron microscopy revealed higher disorder in the pore arrangement in M-SnO 2. This, in turn imparts lower stiffness to M-SnO 2 (elastic modulus, E R≈14.5 GPa) vis-a-vis S-SnO 2 (E R≈20.5 GPa), as obtained using the nanoindenta-tion technique. Thus, the superior battery performance of M-SnO 2 is attributed to its intrinsic material mechanical property. The fluidity of the internal microstructure of M-SnO 2 resulted in a lower degree of aggregation of Sn particles compared to S-SnO 2 and nano-SnO 2 structural stabilization and long-term cyclability. © 2012 Springer-Verlag Berlin Heidelberg.
