Novel processing of lithium manganese silicate nanomaterials for Li-ion battery applications

Lithium manganese silicate positive electrode materials have received great attention because of the two lithium ion capacities and can be realized in ultrafine nanoparticles due to their low volumetric changes upon lithium insertion and extraction. A supercritical fluid process has been adopted to synthesize monodisperse Li2MnSiO4 ultrafine particles and hierarchical nanostructures with a mean particle diameter of 4-5 nm and successfully shown to attain a high electrochemical performance. A reversible capacity (190-220 mA h g(-1)) of more than one lithium ion was obtained for the ultrafine monodisperse nanoparticles and hierarchical nanostructures with good cyclability. The enhanced cyclability was found to be due to the monodisperse nanoparticles, which provide a short length for Li-ion diffusion, and possess low volumetric changes. In addition, the varyingly sized Li2MnSiO4 particles were also synthesized via a supercritical fluid process. This process is simple, rapid, energy saving and broadly applicable to other functional materials.