Cation exchange mediated elimination of the Fe-antisites in the hydrothermal synthesis of LiFePO4. (September 2015)

• Record Type: Journal Article
• Authors: Paolella, Andrea; Bertoni, Giovanni; Hovington, Pierre; Feng, Zimin; Flacau, Roxana; Prato, Mirko; Colombo, Massimo; Marras, Sergio; Manna, Liberato; Turner, Stuart; Van Tendeloo, Gustaaf; Guerfi, Abdelbast; Demopoulos, George P.; Zaghib, Karim
• Is Part Of: Nano energy. Volume 16(2015:Sep.)
• Page Start: 256
• Page End: 267
• Publication Date: 2015-09
• Subjects: Nano-layer -- Antisite -- LiFePO4 -- Hydrothermal -- Mechanism -- Amorphous; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.06.005
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: In this work we elucidate the elimination of mechanism Fe-antisite defects in lithium iron phosphate (LiFePO4 ) during the hydrothermal synthesis. Compelling evidence of this effect is provided by combining Neutron Powder Diffraction (NPD), High Resolution (Scanning) Transmission Electron Microscopy (HR-(S)TEM), Electron Energy Loss Spectroscopy (EELS), X-Ray Photoelectron Spectroscopy (XPS) and calculations. We found: i) the first intermediate vivianite inevitably creates Fe-antisite defects in LiFePO4 ; ii) the removal of these antisite defects by cation exchange is assisted by a nanometer-thick amorphous layer, rich in Li, that enwraps the LiFePO4 crystals. Graphical abstract: Highlights: Vivianite is responsible of the formation of the Fe-antisites. A nanometer thick amorphous layer promotes a cation exchange reaction that removes the Fe- antisites. The removal of Fe-antisites is proved by Neutron Powder Diffraction and HAADF-STEM.