We elucidate the thermodynamics of sodium (Na) intercalation into the sodium super-ionic conductor (NaSICON)-type electrode, NaxV2(PO4)3, for promising Na-ion batteries with high-power density. This is the first report of a computational temperature-composition phase diagram of the NaSICON-type electrode NaxV2(PO4)3. We identify two thermodynamically stable phases at the compositions Na2V2(PO4)3 and Na3.5V2(PO4)3, and their structural features are described for the first time based on our computational analysis. We unveil the crystal-structure and the electronic-structure origins of the ground-state compositions associated with specific Na/vacancy arrangements, which are driven by charge orderings on the vanadium sites. These results are significant for the optimization of high-energy and power densities electrodes for sustainable Na-ion batteries
@article{arxiv.2109.06997,
title = {Phase Stability and Sodium-Vacancy Orderings in a NaSICON Electrode},
author = {Ziliang Wang and Sunkyu Park and Zeyu Deng and Dany Carlier and Jean-Noël Chotard and Laurence Croguennec and Gopalakrishnan Sai Gautam and Anthony K. Cheetham and Christian Masquelier and Pieremanuele Canepa},
journal= {arXiv preprint arXiv:2109.06997},
year = {2021}
}