Formation of hierarchical LiMn ₂ O ₄ dual-porous nanostructures by pyrolysis of gel precursor

Abstract

A precursor-pyrolysing route to fabricate hierarchical LiMn 2 O 4 porous nanostructures is presented. The product was characterised by X-ray powder diffraction, scanning electron microscopy, a transmission electron microscope, a high-resolution transmission electron microscope and a micromeritics analyser. The results show that the resulting material is a honeycomb-like dual-porous structure. One is quasi-hemispherical macropores of several hundred nanometres and the other is slit mesopores of several nanometres. This dual-porous nanostructure is composed of many ultrafine nanocrystallines whose size mainly falls into the range from 3 to 10 nm. Moreover, it has a large Brunauer-Emmett-Teller-specific surface area of 116 m 2 /g. The formation of such dual pores should be attributed to the Kirkendall effect and surface diffusion.