| Autor: |
Cherkashchenko IR; Skolkovo Institute of Science and Technology, 3 Nobel Street, 143025, Moscow, Russia.; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991, Moscow, Russia. nelkh77@gmail.com., Panin RV; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991, Moscow, Russia. nelkh77@gmail.com., Dembitskiy AD; Skolkovo Institute of Science and Technology, 3 Nobel Street, 143025, Moscow, Russia., Novichkov DA; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991, Moscow, Russia. nelkh77@gmail.com., Aksyonov DA; Skolkovo Institute of Science and Technology, 3 Nobel Street, 143025, Moscow, Russia., Antipov EV; Skolkovo Institute of Science and Technology, 3 Nobel Street, 143025, Moscow, Russia.; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991, Moscow, Russia. nelkh77@gmail.com., Khasanova NR; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991, Moscow, Russia. nelkh77@gmail.com. |
| Abstrakt: |
The LiNbV(PO 4 ) 3 phosphate with the anti-NASICON structure ( a = 12.126(1) Å, b = 8.6158(4) Å, c = 8.6959(6) Å, V = 908.5(1) Å 3 , S.G. Pbcn ) has been synthesized using a Pechini sol-gel process. It exhibits reversible multielectron transitions versus Li and Na anodes. In a Li half-cell, it supports a 4e - transfer due to the activation of the Nb 5+ /Nb 3+ and V 4+ /V 2+ redox couples, being the first example of 4d metal redox transitions within the anti-NASICON framework confirmed by XANES measurements. X-ray diffraction performed in ex situ and operando regimes disclosed a single-phase mechanism of lithium (de)intercalation. In a Na half-cell, the material demonstrates reversible uptake of 2.77 Na + ions. Density functional theory calculations revealed percolation barriers of ∼0.5-0.7 eV for Na + hopping, thus supporting the activation of Na + ion diffusion in the NbV(PO 4 ) 3 framework. This study introduces a new approach to improve anti-NASICON-structured electrode materials by utilizing redox transitions of 4d elements for energy storage. |
