Accelerated Removal of Fe-Antisite Defects while Nanosizing Hydrothermal LiFePO4 with Ca2+

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• 作者：Andrea Paolella ; Stuart Turner ; Giovanni Bertoni ; Pierre Hovington ; Roxana Flacau ; Chad Boyer ; Zimin Feng ; Massimo Colombo ; Sergio Marras ; Mirko Prato ; Liberato Manna ; Abdelbast Guerfi ; George P. Demopoulos ; Michel Armand ; Karim Zaghib
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：April 13, 2016
• 年：2016
• 卷：16
• 期：4
• 页码：2692-2697
• 全文大小：444K
• 年卷期：0
• ISSN：1530-6992

文摘

Based on neutron powder diffraction (NPD) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), we show that calcium ions help eliminate the Fe-antisite defects by controlling the nucleation and evolution of the LiFePO₄ particles during their hydrothermal synthesis. This Ca-regulated formation of LiFePO₄ particles has an overwhelming impact on the removal of their iron antisite defects during the subsequent carbon-coating step since (i) almost all the Fe-antisite defects aggregate at the surface of the LiFePO₄ crystal when the crystals are small enough and (ii) the concomitant increase of the surface area, which further exposes the Fe-antisite defects. Our results not only justify a low-cost, efficient and reliable hydrothermal synthesis method for LiFePO₄ but also provide a promising alternative viewpoint on the mechanism controlling the nanosizing of LiFePO₄, which leads to improved electrochemical performances.