Synthesis and characterization of metastable, 20 nm-sized Pna 2 1 -LiCoPO 4 nanospheres
Date Published |
04/2017
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Publication Type | Journal Article
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Authors | |
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DOI |
10.1016/j.jssc.2017.01.015
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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 analysis, differential 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
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Volume |
248
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Year of Publication |
2017
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Pagination |
9 - 17
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ISSN Number |
00224596
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Short Title |
Journal of Solid State Chemistry
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Refereed Designation |
Refereed
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Organizations | |
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