INORGANIC NANOCRYSTALLINE AND HYBRID NANOCRYSTALLJNE PARTICLES AND THEIR CONTRIBUTION TO ELECTRODE MATERIALS FOR LITHIUM BATTERIES

摘要

Nanoscale materials offer the obvious advantage of combining structural effects (inside grain structure) with surface effects or grain-boundary effects. Therefore, the electrochemistry of this type of materials is very different from that of traditional microcrystalline ones mainly due to the contribution of the 'surface defects' allowing strong coulombic interactions between the inserted lithium ions and the surface ions called 'electrochemical grafting'. When this electrochemical grafting is the first electrochemical step to take place, it can favor the power density and the cycling life of electrode materials. As illustrative examples, electrochemical behaviors of nanocrystalline oxides such as LiMn_2O_4, γ-Fe_2O_3, and of nanohybrid inorganic-organic materials such as γ-Fe_2O_3/PPy are presented.