Surface Characterization and Modification of Li Ion Battery Materials - Rick Haasch - MRL - 07232020

Описание: From laptop computers to cellphones, jetliners to racecars, lithium-ion batteries (LIBs) are a part of nearly every aspect of living in today’s world. Over the past decades, the investigation of LIBs has attracted a significant amount of attention. Of importance in the study transition-metal-oxide-based LIBs (TMO-LIBs), is the nature of the interaction of the active oxides with the electrolyte/solvent environment. Many of the issues relating to the performance of TMO-LIBs, such as power fade and capacity loss, are a result of these interactions, with the solid-electrolyte interphase (SEI) playing an important role. The SEI layer provides a protective coating controlling oxide particle wettability, Li-ion transport, electrolyte/solvent oxidation, as well as TM dissolution and migration. This talk will address formation of the SEI layer, its aging, and eventual degradation. Two approaches of cathode surface modification (1) atomic layer deposition (ALD)-alumina-modified lithium nickel cobalt manganese oxide and (2) self-assembled monolayer (SAM)-alkylphosphonate-modified lithium manganese oxide will be presented. Each of these modifications were found to promote Li-ion transport, delay electrolyte/solvent oxidation, as well as reduce manganese dissolution and migration. Characterization methods such as X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and AC impedance spectroscopy will be covered in this talk.