Controlling the reactions occurring at electrode-electrolyte interfaces is key to long-lasting energy storage technologies, such as Li-ion batteries, especially when pushing voltages of operation to increase their energy density.  Extreme potentials reached at the electrodes in a fully charged battery render them too reactive toward the electrolyte, triggering deleterious decomposition reactions.  When transition metal ions are present at the cathode, side reactions can also occur through mechanisms that lead to their dissolution into the electrolyte.  Classical strategies to prevent these undesired reactions and increase electrode durability generally involved post-synthetic treatments of the cathode powders or the use of electrolyte additives.  More recently, new effective options have been added through the demonstration of core-(epitaxial) shell architectures at the level of primary particles.  Yet the description of the exact modes of degradation and the means by which these strategies are effective remains elusive.  During this talk, tools employed to track the structure and chemistry of the surface of cathode particles vis-à-vis their electrochemical properties will be presented.  The power of these tools is maximized by the use of objects of study designed at the highest definition and fidelity, in the form of highly dispersed nanocrystals with conformal shells.  The high fidelity ensures coherence in the data and the representative character of the characterization methods, especially when highly local probes are employed.  The interplay between understanding of electrode-electrolyte processes and the design of novel cathode architectures will be discussed.

Understanding and design of core-shell architectures for battery electrodes based on complex oxides

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.