Efficiency threshold of carbon layer growth in Li4Ti5O12/C composites

Abstract

The core-shell morphology study is crucial for composite materials, comprised of a low conductive core with a highly conductive thin carbon shell. The study analyzed carbon morphology evolution for the two series of Li4Ti5O12/C samples with carbon content increasing from 0.9 to 5.6 wt%. The conventional X-Ray Photoelectron Spectroscopy (XPS) study allowed us to conclude about the efficiency threshold of carbon layer growth over lithium titanate core for two carbon deposition methods - both sucrose and acetylene decompositions. Although the carbon layer thickness is increasing with carbon concentration growth in LTO/C composites, the efficiency of carbon coverage was shown to decrease with the threshold carbon concentrations about 1-2%. The chemical bonding analysis based on the same XPS data was used for C@LTO interface characterization. The proposed approach can be used for optimization of producing different composites with core-shell structure (carbon-based composites, materials with protective layers, and materials with gradient core-shell structure). © The Author(s) 2018. Published by ECS. ; This work was performed within the state task no. 3.6115.2017/8.9 of the Ministry of Education and Science of the Russian Federation and supported by Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006). The equipment of the Ural Center for Shared Use "Modern Nanotechnology" UrFU and JSC Eliont were used. Authors thanks Vasily Lebedev and Alexander Esin for fruitful discussions.