کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1563902 999624 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural stabilities, electronic structures and lithium deintercalation in LixMSiO4 (M = Mn, Fe, Co, Ni): A GGA and GGA + U study
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مکانیک محاسباتی
پیش نمایش صفحه اول مقاله
Structural stabilities, electronic structures and lithium deintercalation in LixMSiO4 (M = Mn, Fe, Co, Ni): A GGA and GGA + U study
چکیده انگلیسی
Dilithium-orthosilicate oxides Li2MSiO4 (M denotes transition metals) have been one of the focuses in the field of new cathode materials for Li-ion batteries recently, due to their possible high capacities and probabilities achieving by experiment. Using the density functional theory within both the generalized gradient approximation (GGA) and GGA + U frameworks, the structural stabilities, electronic structures and delithiation process for the dilithium-orthosilicate oxides Li2MSiO4 (M = Mn, Fe, Co, Ni) are systematically investigated. Within the GGA + U approach, LiMSiO4 is shown to be a stable non-stoichiometric structure, while the compound Li1.5MSiO4 are unstable relative to a two-phase form containing Li2MSiO4 and LiMSiO4, which is consistent with the experimental voltage profiles. For Li0.5MSiO4, though the formation energies are negative for Mn-system and Ni-system, the absolute values are so small that they would be likely to also undergo phase separation at room temperature. The average deintercalation voltages calculated by the GGA + U scheme are in good agreement with the available experimental data. Furthermore, the possibility of the exchange of two electrons per M in Li2MSiO4 is also discussed based on the calculated results.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computational Materials Science - Volume 44, Issue 4, February 2009, Pages 1243-1251
نویسندگان
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