Oxidative decomposition products of synthetic NaFePO4 marićite: nano-textural and electrochemical characterization

Abstract

Single-phase marićite, NaFePO4, was synthesized from monosodium phosphate and iron oxalate at 750°C, at atmospheric pressure. Thermal treatment of synthetic marićite in air indicated oxidative decomposition into Na3Fe 3+ 2(PO4)3 nasicon and-Fe2O3 at temperatures above 225°C. Intergrowth of the reaction products is found to occur at the nanoscale without identified crystallographic relationship with the marićite precursor. Electrochemical activity of the reaction product is confirmed with the reversible insertion of one Na at 2.55 V vs Na + /Na 0 .

In Situ Liquid Electrochemical TEM Investigation of LiMn1.5Ni0.5O4 Thin Film Cathode for Micro‐Battery Applications

“…[53,54] The study of electrochemical activity in battery by 4D-STEM mapping was first reported by Kübel et al [55] in which the authors showed the statistical orientation information on the LiFePO 4 /FePO 4 interface in individual grains with phase mapping extracted from ASTAR data. Other similar works based on the mapping of crystalline phase and orientation mapping using 4D-STEM approach is reported by Su et al [56] and Brunet et al [57] The cross-section bright field TEM image of a pristine lamella is shown in Figure 4a. All layers are easily identified by contrast: Si substrate, Al 2 O 3 , Pt, LMNO thin film, and Pt protective coating.…”