NUANCE staff recognized for work using in-situ TEM
first sodiation and desodiation processes. (a-h) Typical morphological evolution of
Co3O4 clusters supported by carbon nanotube during the first sodiation (i) Diffraction
pattern of the phase after full sodiation. (j-p) Morphological evolution of this cluster in the
first desodiation, with particle size increasing. (q) Diffraction pattern of the final phase
after desodiation.
The Journal of Materials Chemistry A published NUANCE staff members Dr. Qianqian Li, Dr. Jinsong Wu, Dr. Junming Xu and Dr. Vinayak Dravid's work on "Synergistic Sodiation of Cobalt Oxide Nanoparticles and Conductive Carbon Nanotubes (CNT) for Sodium-ion Battery."
Abstract:
Replacing lithium with sodium in batteries for energy storage is of enormous interest,
especially from practical and economic considerations. However, it has proved difficult to
achieve competitive figures of merit for sodium-ion batteries due to lack of detailed
understanding of the reaction mechanism(s). Herein we report sodium electrochemical
conversion reaction with Co3O4 nanoparticles decorated on carbon nanotubes (Co3O4/CNT)
utilizing in-situ TEM, down to the atomic-scale. We observe synergetic effects of the two
nanoscale components, which provide insights into a new sodiation mechanism, facilitated
by Na-diffusion along CNT backbone and CNT-Co3O4 interfaces. A thin layer of
amorphous low conductivity Na2O forms on the CNT surfaces at the beginning of sodiation.
Conversion reaction results in the formation of ultrafine metallic Co nanoparticles and
polycrystalline Na2O, and fast diffusion of the reaction products which might due to the
quick migration of Na2O under electron beam. In the desodiation, the dissociation of Na2O
and formation of Co3O4 due to the de-conversion reaction are observed.