Solvent free PEO-NaClO₄:Na₃Zr₂Si₂PO_{1 2} composite solid polymer electrolytes: Comparison of conductive properties of "ceramics-in-polymer" and "polymer-in-ceramics"

In this work, a comparative study of the conductive properties of the PEO-NaClO4:NZSP composite solid polymer electrolyte (SPE) films was carried out in a wide range of the NZSP filler content (5-250 wt%), and the "ceramicsin-polymer" and "polymer-in-ceramics" fields were studied. The optimal composition of EO:NaClO4 with molar ratio is 10:1 to obtain SPE films with low crystallinity (12.2%) and high ionic conductivity (1.7.10(-5) S.cm(-1) at 30 degrees C) was determined. An additional reduction in crystallinity to 4.5% was achieved due to the introduction of NZSP filler. High ionic conductivity and low apparent activation energy were obtained with a content of NZSP filler of 25 wt% (sigma = 3.56.10(-5) S.cm(- 1) (30 degrees C) and E-a = 0.118 eV) for "ceramics-in-polymer" and 150 wt% (sigma = 2.74.10(-5) S.cm(- 1) (30 degrees C) and E-a = 0.116 eV) for "polymer-in-ceramics" fields. The Na+ ion transference number tNa(+) was determined for PEO-NaClO4 and PEO-NaClO4:NZSP composites. The introduction of NZSP filler increases tNa(+) from 0.45 (EO:NaClO4 = 10:1) to 0.55 (25 wt% of NZSP filler) and 0.77 (150 wt% of NZSP filler). The NVP||PEO-NaClO4:NZSP-150 wt%||Na half-cell was tested at 60 degrees C and the average charge-discharge capacity of similar to 60 mAh.g(- 1) was achieved.