ALBA Synchrotron
CNRS chemists synthesized and studied new compositions of materials for positive electrodes of sodium-ion batteries that constitute a sustainable alternative to lithium-ion batteries. These new electrodes have an increased energy density. A scientific advance recently published in the journal Nature Materials.
Faced with the growing demand for energy storage systems, high-performance lithium-ion batteries have become unbeatable on the market. However, their environmental impact and the uneven distribution of lithium resources raise questions. Their “cousins”, sodium-ion batteries, seem to be a promising alternative given the abundance and more homogeneous distribution of sodium. The various possible electrode materials are thus the subject of numerous studies to increase their performance, power and energy densities. In particular, NaSICON (sodium super ionic conductor) type materials composed of sodium, vanadium and phosphate are attracting keen interest as positive electrode materials because they have a particularly robust crystalline structure.
An international team of scientists in partnership with the company TIAMAT recently published in the journal Nature Materials the discovery of a new compound with increased energy density in the NaSICON family. To do this, they synthesized and chemically isolated previously unexplored phases, with the general formula NaxV2(PO4)3 with x between 1.5 and 2.5. These compounds were obtained using an innovative solid-state synthesis method at a moderate temperature of 500°C. Unlike standard materials, these new compositions feature single-phase sodium extraction/insertion mechanisms, ensuring continuous voltage variation during use. This results in a 15% increase in theoretical energy density, from 396 Wh/kg to 458 Wh/kg.
These discoveries pave the way for more efficient electrodes and more effective batteries that can compete with current technologies while being more environmentally friendly. This opens up a broader field of applications for sodium-ion batteries while strengthening their potential as a sustainable replacement for lithium batteries.
The study has been carried out by scientists from the l’Institut de chimie de la matière condensée de Bordeaux (CNRS/Université de Bordeaux/Bordeaux INP), du Laboratoire de réactivité et de chimie des solides (CNRS/Université de Picardie Jules Verne), from the National University of Singapore, the University of Houston (United States) and the ALBA Synchrotron, in particular the MSPD beamline.
Reference: Obtaining V2(PO4)3 by sodium extraction from single-phase NaxV2(PO4)3 (1 < x < 3) positive electrode materials. Sunkyu Park, Ziliang Wang, Kriti Choudhary, Jean-Noël Chotard, Dany Carlier, François Fauth, Pieremanuele Canepa, Laurence Croguennec & Christian Masquelier. Nature Materials (2024). https://doi.org/10.1038/s41563-024-02023-7