Fig. 3
From: Electrochemically driven conversion reaction in fluoride electrodes for energy storage devices
a Voltage profile of FeF2 during the first discharge at 0.01C with different lithiation stages labeled as a–f. b Ex situ X-ray PDF profiles at corresponding electrochemical stages as shown in a (reproduced with permission from ref. 9, copyright American Chemical Society 2011). c Scheme of electrochemical cell for in situ TEM measurements. d TEM images of a collection of particles reacting with Li as a function of reaction time. e TEM image of Fe nanoparticles converted from a single FeF2 particle, inset: fast Fourier transform (FFT) pattern of selected region. f Li-Fe-F phase diagram by first-principle calculations. g Scheme of conversion reaction propagation within a single FeF2 particle via a “layer-by-layer” process (reproduced from ref. 22)
