کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6604135 1424092 2018 27 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ball-in-ball hierarchical design of P2-type layered oxide as high performance Na-ion battery cathodes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Ball-in-ball hierarchical design of P2-type layered oxide as high performance Na-ion battery cathodes
چکیده انگلیسی
Hierarchical microstructures assembled with nanostructures can effectively enhance the electrochemical performances of electrode materials for rechargeable Li/Na-ion batteries. Due to the large ionic radius of sodium, this kind of design and synthesis is more important for Na-battery cathodes, which represent a cost-effective alternative for energy storage applications. Here ball-in-ball hierarchical microspheres assembled with micron shaped flakes of the P2-type Na0.7Ni0.18Mn0.64Co0.18O2 have been designed and synthesized via hydrothermal reaction followed by stepwise calcination process. As a cathode material of the Na-ion battery, this novel and uniform hierarchical structure exhibits very high specific capacity and superior rate performance with discharge capacities of 208 mAh g−1 at 0.05 C and 46 mAh g−1 at 10 C, and an excellent cycling stability with about 78% capacity retention at 1 C after 50 cycles. These performances are better than any layered oxide cathode material for reversible Na-ion batteries reported in the literature, prepared via the conventional solid-state method. Combining ex-situ x-ray absorption spectroscopy characterization, x-ray diffraction, field emission scanning electron microscopy, scanning transmission electron microscopy and electrochemical characterization, we demonstrate that the superior performances can be attributed to the unique ball-in-ball hierarchical structure assembled with micron shaped flakes. This configuration could effectively reduce the path of Na ion diffusion, increases the contact area between electrodes and electrolyte and buffers the volume changes during the Na ion insertion/extraction processes.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 265, 1 March 2018, Pages 284-291
نویسندگان
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