Study of thin film composites based on LiCoO2 and C60 using neutron depth profiling and atomic force microscopy

Abstract

In this work, two thin hybrid composites based on organic-like fullerenes (bucky balls C₆₀) and inorganic compounds of lithium cobalt oxide (LiCoO₂) were prepared. The composites were synthesized by a combined method of ion sputtering and evaporation. The prepared samples were sandwiched between 2 gold electrodes and subjected to charging at an applied small voltage. After each charging process, the samples were analyzed using two appropriate methods—the surface morphology was monitored using AFM (Atomic Force Microscopy), and lithium depth concentration profiles were measured using NDP (Neutron Depth Profiling). The results of the measurements showed that both types of composite experienced significant changes both in the surface morphology and especially in the depth distribution of lithium. The test confirmed the expectation that the unusual hybrid combination of organic and inorganic phases is electrochemically active and exhibits characteristics of Li battery behavior.