2018/02/12 by T. J. Willis, D. G. Porter, David Voneshen +6 · 1 citation
Engineering · Physics and Astronomy · #Advanced Battery Materials and Technologies #Advancements in Battery Materials #Semiconductor materials and interfaces
paper · pdf · doi:10.1038/s41598-018-21354-5
openalex publication_date 2018/02/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Abstract High performance batteries based on the movement of Li ions in Li x CoO 2 have made possible a revolution in mobile electronic technology, from laptops to mobile phones. However, the scarcity of Li and the demand for energy storage for renewables has led to intense interest in Na-ion batteries, including structurally-related Na x CoO 2 . Here we have determined the diffusion mechanism for Na 0.8 CoO 2 using diffuse x-ray scattering, quasi-elastic neutron scattering and ab-initio molecular dynamics simulations, and we find that the sodium ordering provides diffusion pathways and governs the diffusion rate. Above T ~ 290 K the so-called partially disordered stripe superstructure provides channels for quasi-1D diffusion, and melting of the sodium ordering leads to 2D superionic diffusion above T ~ 370 K. We obtain quantitative agreement between our microscopic study of the hopping mechanism and bulk self-diffusion measurements. Our approach can be applied widely to other Na- or Li-ion battery materials.