nl6b00334_si_001.pdf (4.5 MB)
Accelerated Removal of Fe-Antisite Defects while Nanosizing Hydrothermal LiFePO4 with Ca2+
journal contribution
posted on 2016-03-11, 00:00 authored by 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 ZaghibBased
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.