Ion conductive mixed crystal
AssigneeVarta Batterie Aktiengesellschaft
InventorsUlrich von Alpen, Reinhard Brautigam, Antony Oliapuram
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Abstract
A mixed crystal of the general composition Na.sub.1+ax Zr.sub.2+22/3x-ax Si.sub.x P.sub.3-x O.sub.12-2/3x with 0.8.ltoreq.a.ltoreq.0.9 and 1.8.ltoreq.x.ltoreq.2.3, has a particularly favorable Na-ion conductivity, particularly when a=0.88 and x=2.2. This makes its use desirable as the solid electrolyte in Na/S cells. The high density of the single phase monoclinic crystallized material, which reaches almost 3.10 g/cm.sup.3, is the result of high temperature sintering, carried out in pure oxygen.
Claims2
A mixed crystal for use as the ion conductive solid electrolyte in galvanic elements formed of the components Na.sub.2 O, ZrO.sub.2, P.sub.2 O.sub.5 and SiO.sub.2, wherein the composition is expressed by the general formula
- Na.sub.1+ax Zr.sub.2+2/3x-ax Si.sub.x P.sub.3-x O.sub.122/3x,
- a being a constant with a numerical value between 0.8 and 0.9 and x being a variable parameter with numerical values of 1.8 to 2.3.
Dependencies are inferred from the claim text.