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

作者：Paolella Andrea; Turner Stuart; Bertoni Giovanni; Hovington Pierre; Flacau Roxana; Boyer Chad; Feng Zimin; Colombo Massimo; Marras Sergio; Prato Mirko; Manna Liberato; Guerfi Abdelbast; Demopoulos George P; Armand Michel; Zaghib Karim^*

来源：Nano Letters, 2016, 16(4): 2692-2697.

DOI：10.1021/acs.nanolett.6b00334

• Antisite
• LiFePO4
• calcium
• surface
• defects
• hydrothermal

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.

• 出版日期2016-4
• 单位McGill