High-Pressure Investigation of Li2MnSiO4 and Li2CoSiO4 Electrode Materials for Lithium-Ion Batteries

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• 作者：D. Santamar铆a-P茅rez ; U. Amador ; J. Tortajada ; R. Dominko ; M. E. Arroyo- de Dompablo
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：May 21, 2012
• 年：2012
• 卷：51
• 期：10
• 页码：5779-5786
• 全文大小：562K
• 年卷期：v.51,no.10(May 21, 2012)
• ISSN：1520-510X

文摘

In this work, the high-pressure behavior of Pmn2₁-Li₂MnSiO₄ and Pbn2₁-Li₂CoSiO₄ is followed by in situ X-ray diffraction at room temperature. Bulk moduli are 81 and 95 GPa for Pmn2₁-Li₂MnSiO₄ and Pbn2₁-Li₂CoSiO₄, respectively. Regardless of the moderate values of the bulk moduli, there is no evidence of any phase transformation up to a pressure of 15 GPa. Pmn2₁-Li₂MnSiO₄ shows an unusual expansion of the a lattice parameter upon compression. A density functional theory investigation yields lattice parameter variations and bulk moduli in good agreement with experiments. The calculated data indicate that expansion of the a lattice parameter is inherent to the crystal structure and independent of the nature of the transition-metal atom (M). The absence of pressure-driven phase transformation is likely associated with the incapability of the Li₂MSiO₄ composition to adopt denser structures while avoiding large electrostatic repulsions.