Synthesis and characterization of metastable, 20 nm-sized Pna 2 1 -LiCoPO 4 nanospheres

Date Published
04/2017
Publication Type
Journal Article
Authors
DOI
10.1016/j.jssc.2017.01.015
Abstract

The majority of research activities on LiCoPO4 are focused on the phospho-olivine (space group Pnma), which is a promising high-voltage cathode material for Li-ion batteries. In contrast, comparably little is known about its metastable Pna21 modification. Herein, we present a comprehensive study on the structure–property relationships of 15–20 nm Pna21-LiCoPO4 nanospheres prepared by a simple microwave-assisted solvothermal process. Unlike previous reports, the results indicate that the compound is non-stoichiometric and shows cation-mixing with Co ions on the Li sites, which provides an explanation for the poor electrochemical performance. Co L2,3-edge X-ray absorption spectroscopic data confirm the local tetrahedral symmetry of Co2+. Comprehensive studies on the thermal stability using thermogravimetric analysisdifferential scanning calorimetry, and in situ powder X-ray diffraction show an exothermic phase transition to olivine Pnma-LiCoPO4 at 527 °C. The influence of the atmosphere and the particle size on the thermal stability is also investigated.

Journal
Journal of Solid State Chemistry
Volume
248
Year of Publication
2017
Pagination
9 - 17
ISSN Number
00224596
Short Title
Journal of Solid State Chemistry
Refereed Designation
Refereed
Organizations
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