We report on a preparation of nano-sized calcium cobaltite materials with good homogeneity and their detailed lithium reactivity for the application to Li-ion battery electrodes. Derived from Na_xCoO₂, the cobaltite, Ca₃Co₄O₉ has a misfit structure alternating [CoO₂] and [Ca₂CoO₃] with CdI₂- and rocksalt-type layers, respectively. Compared to the carbon-based anode, transition metal oxides have an extremely large reversible capacity arising from their displacement reactions. Accordingly, we designed a series of Ca₃(Co₃M)O₉ compounds in order to substitute cation sites in this layered structure with transition-metal, M (M = Co, Cu, and Fe). After the intermediate formation of polybasic chelates using citric acid, HOC(CH₂CO₂H)₂×CO₂H with metallic ions, each powder was successfully produced at 700^oC for 2 hours in O₂ atmosphere. The obtained powders show a two-dimensional morphology consisting of very thin micalike nano-platelets. We found that these cobaltite nanomaterials show excellent lithium reactivity, which results in a high reversible specific capacity. In addition, the formation of nanocomposite composed of highly dispersed transition-metal nano grains embedded into a Li₂O and CaO matrix with pseudo-amorphous character is also observed during the charge/discharge process, using a high resolution transmission electron microscopy.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/11373 must be provided.

1. Preparation of Brookite-Type TiO₂/Carbon nanocomposite Electrodes for the Application to Li-Ion Batteries