Conference Presentation (Invited)

FZJ-2018-06878

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Fast, faster, fastest: Ionic conduction in NaSICON materials

Tietz, F. (Corresponding author)FZJ*

2018

Abstract: Na+ Super-Ionic CONductors (NaSICON) consist of a 3D framework of corner-shared ZrO6 octahedra and (Si,P)O4 tetrahedra, joined by inter¬connected channels providing a Na+ conduction pathway between Na(1) and Na(2) positions. The original composition Na3Zr2Si2PO12 can be modified according to the generalized formula as Na1+2w+x-y+z M2+w M3+x M5+y Zr2-w-x-y (SiO4)z (PO4)3-z. To anticipate a fast conducting NaSICON material, the composition should follow specific design parameters:1. The size of transition metal cations (reff = 0.72 Å)2. The Na content (3 – 3.5 moles Na/formula unit)3. The crystal structure (monoclinic distortion affecting the structural bottleneck)So far three series of NaSICON materials were designed to verify the proposed design parameters: Na3+xScxZr2-xSi2PO12, Na3+xSc2SixP3-xO12 and Na1+2xAlxYxZr2-2xSiyP3-yO12. For the first two series the maximum conductivity was indeed obtained for x = 0.4, with the highest Na+ ion conductivity in polycrystalline NaSICON materials ever reported for Na3.4Sc0.4Zr1.6Si2PO12 (4 mS cm-1).

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Contributing Institute(s):

1. Helmholtz-Institut Münster Ionenleiter für Energiespeicher (IEK-12)
2. Werkstoffsynthese und Herstellungsverfahren (IEK-1)

Research Program(s):

1. 131 - Electrochemical Storage (POF3-131) (POF3-131)

Appears in the scientific report 2019

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