Sulfate-Substituted Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> Nanodots Embedded in Carbon Nanotubes for Ultrafast Sodium-Ion Storage.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41053998.
- Also identified by DOI 10.1021/acs.nanolett.5c03272.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Polyanion-substituted sodium vanadium phosphate (Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>, NVP) derivatives, including SO<sub>4</sub>, BO<sub>3</sub>, WO<sub>4</sub>, and SiO<sub>4</sub> substitutions, were systematically synthesized and impregnated with a nanocarbon network via ultracentrifugation. Among them, nanosized (5-30 nm), highly crystalline, and well-dispersed sulfate-substituted NVP (NVPS) nanodots were directly nucleated onto multiwalled carbon nanotubes, enabling ultrafast electrochemical kinetics. This nanoscale architecture delivered exceptional rate capability, achieving 97 mAh g<sup>-1</sup> at 1000C (3.6 s discharge), corresponding to 83% of the theoretical capacity, outperforming conventional NVP. The electrochemical kinetics analysis using a cavity microelectrode revealed reduced polarization, enhanced capacitive charge storage, and rapid sodium ion diffusion during intercalation/deintercalation, facilitated by the conformal interface between NVPS and MWCNT, possibly by sulfate-induced surface modifications. These findings establish polyanion substitution and ultracentrifugation-assisted materials processing as a transformative strategy for overcoming intrinsic transport limitations in NASICON-type phosphates, positioning NVPS as a benchmark material for next-generation high-power sodium-ion batteries and hybrid capacitors.