A promising breakthrough for the deployment of sodium-ion batteries 🔋

Chemists from CNRS have synthesized and studied new compositions of materials for positive electrodes in sodium-ion batteries, which represent a sustainable alternative to lithium-ion batteries. These new electrodes exhibit increased energy density. This breakthrough was published in the journal Nature Materials.


In light of the growing demand for energy storage systems, highly efficient lithium-ion batteries have become dominant in the market. However, their environmental impact and the unequal distribution of lithium resources raise concerns. Their counterparts, sodium-ion (Na-ion) batteries, appear to be a promising alternative due to the abundance and more even distribution of sodium.

Various electrode materials are being extensively studied to improve their performance, power density, and energy density. In particular, materials of the NaSICON type (short for "sodium super ionic conductor"), composed of sodium, vanadium, and phosphate, are garnering significant interest as positive electrode materials due to their exceptionally robust crystalline structure.

An international team of scientists, in collaboration with the company TIAMAT, recently published in the journal Nature Materials the discovery of a new compound with increased energy density within the NaSICON family. For this, they synthesized and chemically isolated previously unexplored phases with the general formula Na_xV₂(PO₄)₃, where x ranges between 1.5 and 2.5. These compounds were obtained through an innovative solid-state synthesis method at a moderate temperature of 500°C (932°F).

Unlike standard materials, these new compositions exhibit single-phase sodium extraction/insertion mechanisms, enabling a continuous voltage variation during use. This results in an increase in theoretical energy density by 15%, rising from 396 Wh/kg to 458 Wh/kg.

These findings, published in the journal Nature Materials, pave the way for more efficient electrodes and batteries capable of competing with current technologies while being more environmentally friendly. This development suggests a broader range of applications for sodium-ion batteries, further enhancing their potential as a sustainable replacement for lithium-ion batteries.

Author: AVR

Reference:
Obtaining V₂(PO₄)₃ by sodium extraction from single-phase Na_xV₂(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