Porous carbon/tin (IV) oxide monoliths as anodes for lithium-ion batteries

A monolithic, three-dimensionally ordered macroporous/mesoporous carbon/tin (IV) oxide (3DOM/m C/SnO₂) nanocomposite was prepared and tested as an anode material for lithium-ion batteries. A macro-/mesoporous glassy carbon (3DOM/m C) monolith was first synthesized from a triconstituent precursor, using a polymer colloidal crystal and a nonionic surfactant as the templates for macropores and mesopores, respectively. Tin (IV) oxide nanocrystals were then introduced into the mesopores of the carbon monolith via an infiltration- hydrolysis process while maintaining connections between macropores. The composite electrode exhibited superior reversible lithium capacity over a carbon/tin dioxide electrode without any designed mesostructure and also over similarly templated glassy carbon electrodes lacking the tin oxide component. The initial discharge capacity was 472 mAh g^-1 and remained above 292 mAh g^-1 for 100 cycles at 50 mA g^-1. The formation of stable solid-electrolyte interphase layers contributed to the good cycleability of 3DOM/m C/SnO₂. The structural and morphological changes of the electrode after cycling were evaluated by scanning and transmission electron microscopy and by X-ray diffraction.