Synthesis of Li2MnSiO4/C nanocomposites for lithium battery cathode employing sucrose as carbon source

Abstract

Li2MnSiO4/C nanocomposites were prepared by a combination of spray pyrolysis and ball milling followed by annealing, employing sucrose as the carbon source. The effect of the concentration of sucrose solution on the physical and electrochemical properties of Li2MnSiO4/C nanocomposites was investigated. X-ray diffraction analysis indicated that the peaks of the Li2MnSiO4/C nanocomposites were indexed to the orthorhombic structure of the Pmn21 space group. Field-emission scanning electron microscopy and transmission electron microscopy verified that the Li2MnSiO4/C nanocomposites finally obtained from 0.1molL−1 sucrose solution were agglomerates of Li2MnSiO4 primary particles less than 100nm in size, and that there are thin carbon layers partially formed on the surface of these agglomerates. A Li2MnSiO4/C nanocomposite electrode with 5wt.% acetylene black was used as a cathode for rechargeable lithium batteries, and electrochemical measurement was carried out using Li|1M LiPF6 in EC:DMC=1:1| Li2MnSiO4/C cells at room and elevated temperatures. The Li2MnSiO4/C nanocomposite electrodes delivered first-discharge capacities of 184mAhg−1 at 0.05C and 115mAhg−1 at 1C. Moreover, it exhibited a first-discharge capacity of 225mAhg−1 at 0.05C and 60°C.