Collision and Oxidation of Single LiCoO2 Nanoparticles Studied by Correlated Optical Imaging and Electrochemical Recording.

Electrochemists have witnessed the rapid development of single nanoparticle collision (SNC) in the past decade as a powerful technology to study the electrochemical activity of single nanoparticles (NPs). One of the ultimate goals of SNC is to build the structure-activity relationship in a bottom-up way, which requires the correlation between the electrochemical activity and the morphology/structure of the same individual. In the present work, we demonstrated the capability of combining surface plasmon resonance microscopy (SPRM) and conventional electrochemical recordings to correlate the size and activity of single LiCoO2 NPs. Electrochemical recordings provided the rate and amount of electron transfer associated with a single LiCoO2 NP during its collision onto the electrode. SPRM measured the size and the location of the collision of the very same individual, which further allowed for the morphology characterization with scanning electron microscopy. The present work was the first attempt to correlate the electrochemical activity and the morphology of single Li-ion storage NPs during collision events, which not only expanded the SNC technology to study versatile electro-active cathode and anode nanomaterials in different kinds of batteries, but also paved a way toward the structure-activity relationship of Li-ion storage nanomaterials with significant implications for Li-ion batteries.