Advanced Electron Microscopy of Layered-Oxide Cathode Materials

Thursday, 28 May 2015: 15:40
Salon A-2 (Hilton Chicago)
P. J. Phillips (University Of Illinois At Chicago), C. Kim (University of Illinois at Chicago), J. Bareno (Argonne National Laboratory), T. Yi (University of Illinois at Chicago), J. Cabana (JCESR at University of Illinois at Chicago), D. P. Abraham (Argonne National Laboratory), and R. F. Klie (University Of Illinois At Chicago)
The role of aberration-corrected scanning transmission electron microscopy (STEM) in materials characterization is examined with respect to layered-oxide cathode materials for battery applications. STEM-based methods are quickly becoming the most promising characterization tools for these materials, owed largely to the wide-range of techniques available on advanced STEM instruments, including the direct imaging of both heavy and light elements, and both energy-dispersive X-ray (EDX) and electron energy loss (EEL) spectroscopies. The current talk will focus on multiple materials, including Li- and beyond Li-ion oxides, characterized via STEM methods, in pristine, cycled, and in-situ irradiated states. The latter allows for single particle tracking of the dynamic processes occuring upon Li and O loss from the material. Various imaging modes, including high/low angle annular dark field (H/LAADF) and annular bright field (ABF), in conjunction with EELS/EDX, will be used extensively for this analysis, while parameters such as Mn valence, O presence, and light element occupation and intercalation will be discussed.