Operando monitoring the nanometric morphological evolution of TiO2 nanoparticles in a Na-ion battery. (December 2018)

• Record Type: Journal Article
• Authors: Santoro, Gonzalo; Amarilla, José Manuel; Tartaj, Pedro; Vázquez-Santos, María Beatriz
• Is Part Of: Materials today energy. Volume 10(2018)
• Page Start: 23
• Page End: 27
• Publication Date: 2018-12
• Subjects: Operando studies -- X-ray scattering -- Batteries -- Morphology -- Titania nanoparticles; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2018.08.005
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Na-ion batteries are nowadays receiving renewed attention because of its propitiousness for large-scale stationary applications. Although the Na storage mechanism is still not completely understood, TiO2 nanoparticles are very promising active anode materials in Na-ion batteries provided that a correct dispersion is achieved within the battery electrode. Whilst the structural changes, either in crystallinity or crystalline phase, that occur during operation are receiving much recent attention, the nanometric morphological evolution of the TiO2 nanoparticles within the electrode is yet to be thoroughly addressed, despite its implication in battery efficiency. In the present work, operando small-angle x-ray scattering studies on TiO2 /Na-ion batteries show that whereas the nanoparticle size is preserved during the discharge-charge cycles, the mean distance between nanoparticles increases. The observed morphological changes are consistent with electrode swelling and nanoparticle aggregation during operation, being one phenomenon dominant over the other depending on the applied density current; thus, depending on the differences in ion diffusion within the electrode. Graphical abstract: Highlights: Morphological changes at the nanoscale of TiO2 nanoparticles are monitored during Na-ion battery operation. During the discharge-charge battery cycles, the nanoparticle center-to-center mean distance increases. Aggregation and swelling phenomena are identified as being responsible for the observed experimental results.