Previous studies of other Li-containing materials by ELNES or XANES showed that the positions of Li-K edges can vary by more than 5 eV depending on the particular chemical environment of the Li atoms, as reflected in the Mulliken electronegativities or oxidation numbers of neighbouring atoms. 18,63 In our work, the main Li-K peaks were observed to lie at around 61–62 eV for all materials except Li 0.33 La.
8/1/2015 · The Li K-edge intensity ratio between LTO and Li-LTO roughly corresponds to the Li-concentration ratio between Li 4 Ti 5 O 12 and Li 7 Ti 5 O 12, similarly to the STEM-EELS spectral map . We have shown for the first time that the elemental map of Li can be performed by the REELS technique for usual samples without special preparation.
The scanning REELS technique using the SEM apparatus has been applied to Li K-edge spectra. The present SEM-REELS technique can provide the distinct fine structure. For Li 4 Ti 5 O 12 and Li 7 Ti 5 O 12 electrode samples, the Li distribution has been successfully visualized by the REELS spectrum-imaging scheme.
The Li K-edge threshold E th is defined as the energy position at the half height of the edge jump and the vertical dotted line denotes the Li K-edge threshold for elemental Li (54.8 eV). [1] [1], The Li K-edge spectroscopy and mapping, combined with electron microscopy-based structural analysis provide a comprehensive view of the structure-correlated lithium intercalation in graphite and …
monochromators.22–24 The latter allows Li – K edge spectra to be used to measure Li concentrations and distributions quantita-tively with nanoscale resolution, as reported for materials LiCoO 2, 25,26 LiFePO 4 27,28 and Li 2MnO 3. 29 One drawback of this method, however, is.
3/19/2014 · The authors clarified fine structures of Li – K edge of LiCoO 2 reflecting core–hole effects, using monochromated transmission electron microscopy—electron energy- loss spectroscopy (TEM– EELS ) and first-principles calculations. Variation of interband transitions into empty Co 3d states hybridized with O 2p states with decrease in x of Li x CoO 2 was also presented.
EELS maps of these valence features give comparable results to the Li-K edge EELS maps of LiCoO2. With some spectral processing, the valence EELS maps more accurately highlight the morphology and distribution of LiCoO2 than the Li – K edge maps, especially in thicker sample regions. This approach is beneficial for cases where sample thickness or …
Fine structures in the Li K edge region can thus give clues on the chemistry of the intercalation in this compound like in others.39 However, in the prospect of quickly determining phases in LixFePO4 samples via energy filtered images, the Fe M2,3 / Li K edge region is clearly not an optimum choice. FIG. 4. (a) Experimental Fe-M and Li – K edges …
Degradation Analysis of LiCoO 2 Positive Electrode Material of a Li -Ion Battery Using the Li K – Edge Signal Obtained from STEM- EELS Measurements. Noboru Taguchi 1), Hikari Sakaebe 1), Kuniaki Tatsumi 1), Tomoki Akita 1) 1) Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST) …
