کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7737561 | 1497978 | 2014 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Evaluation of thermal stability in Li0.2NixMn(1âx)/2Co(1âx)/2O2 (x = 1/3, 0.6, and 0.8) through X-ray absorption fine structure
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
الکتروشیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Evaluation of thermal stability in Li0.2NixMn(1âx)/2Co(1âx)/2O2 (x = 1/3, 0.6, and 0.8) through X-ray absorption fine structure Evaluation of thermal stability in Li0.2NixMn(1âx)/2Co(1âx)/2O2 (x = 1/3, 0.6, and 0.8) through X-ray absorption fine structure](/preview/png/7737561.png)
چکیده انگلیسی
High-Ni-content layer-structured cathode materials for lithium-ion secondary batteries have high capacity but they suffer from poor thermal stability. We studied the mechanism responsible for their thermal stability to make them more stable. We used X-ray absorption fine structure (XAFS) spectra to clarify the changes in the oxidation states and the local structures for each transition metal in Li0.2NixMn(1âx)/2Co(1âx)/2O2 (x = 1/3, 0.6, and 0.8) at high temperature. The X-ray absorption near edge structure (XANES) spectra indicated that the oxidation state of Ni and Co changed due to heating. Although, pre-edge of XANES spectra indicated that the occupation sites of Co ions changed from octahedral to tetrahedral, Mn ions remained in the octahedral sites at high temperature. The extended X-ray absorption fine structure (EXAFS) results supported the change in the occupation sites of Co and Mn ions due to heating. It can be concluded that Co and Mn affected thermal stability of those Ni-based cathode materials differently. The Co ions migrated from octahedral to tetrahedral sites, and they stably occupy tetrahedral sites. Hence, so the structural change from spinel to rock-salt is suppressed. The oxidation state of Mn is stable and remains unchanged in layer structure at high temperature.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Power Sources - Volume 254, 15 May 2014, Pages 338-344
Journal: Journal of Power Sources - Volume 254, 15 May 2014, Pages 338-344
نویسندگان
Hiroaki Konishi, Masanori Yoshikawa, Tatsumi Hirano, Kishio Hidaka,