Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the LiNaV(PO) System.

In the present work, we studied crystal phases in the LiNaV(PO) system over a wide range of prepared by four synthesis methods: mechanochemically assisted solid-state synthesis, 'soft chemistry' sol-gel approach, chemical (CIE) and electrochemical (EIE) ion exchange starting from LiV(PO) (anti-NASICON, 2/ S.G.), and NaV(PO) (NASICON, 2/ S.

Understanding of the Mechanism and Kinetics of the Fast Solid-State Reaction between NaF and VPO to Form NaV(PO)F.

The solid-state reaction between NaF and VPO is widely used to produce NaV(PO)F, a promising cathode material for sodium-ion batteries. In the present work, the mechanism and kinetics of the reaction between NaF and VPO were investigated, and the effect of preliminary high-energy ball milling (HEBM) was studied using time-resolved synchrotron powder X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, etc. The reaction was attributed to a "dimensional reduction" formalism; it proceeds quickly with the unilateral diffusion of Na and F ions into VPO particles as a limiting stage.