本研究引用無機晶體結構資料庫 (ICSD) 之前人文獻數據MZr2(PO4)3
(M=Li, Na, K, Cs)與Na1+xZr2SixP3-xO12 (0 < x < 3) 兩種系列成分，探討晶體結構與離子導電率關聯性，由於NASICON 化合物中鈉離子會經由氧離子組成之瓶頸 (bottleneck) 進行穿梭，利用Rietveld 精修法及Diamond 繪圖軟體計算離子通道中三角形及內切圓瓶頸大小，兩者趨勢一致。再以液相輔助固相反應法製備粉末，並使用XRD 進行煅燒粉末之相鑑定，以600℃/6 h-1000℃/12 h 兩階段煅燒可合成出接近單一相之NaZr2(PO4)3、Na2Zr2SiP2O12、Na3Zr2Si2PO12、KZr2(PO4)3 固溶體，及Na0.5K0.5Zr2(PO4)3 以兩相組成之部分固溶體，而Na3-xKxZr2Si2PO12(x=3, 1, 0.5, 0.1, 0.05) 因K+離子與Na+半徑差異較大，因此無法形成固溶體。將NaZr2(PO4)3、KZr2(PO4)3、Na0.5K0.5Zr2(PO4)3 加入2 wt% MgO，以1200℃/10 h 進行燒結，Na2Zr2SiP2O12、Na3Zr2Si2PO12 不添加燒結助劑下以1250℃/10 h 進行燒結，皆可使燒結相對密度達90%以上。最後將陶瓷體使用直流電量測導電率，以Na3Zr2Si2PO12 導電率最佳，且MZr2(PO4), (M=Na,Na0.5K0.5, K)之室溫離子導電率與瓶頸尺寸呈負相關，隨著K+含量愈高，離子通道愈大，導電率愈低。Na1+xZr2SixP3-xO12 (x=0, 1, 2) 之室溫離子導電率與瓶頸尺寸呈正相關，隨著Si4+含量增加，離子通道愈大，導電率愈高。

NASICON material is a promising solid-state electrolyte because of its distinctive crystal structure and high ionic conductivity. The bottleneck size for the ionic channel of crystal structure affects Na+ ionic conductivity. To discuss the relation between crystal structure and ionic conductivity, we cited the data about MZr2(PO4)3 (M=Li, Na, K, Cs) and Na1+xZr2SixP3-xO12 (0 < x < 3) from the ICSD database. In this study, we calculate the area of the bottleneck by the shape of a triangle and an inscribed circle. The powder of NASICON compounds is prepared by solution-assisted solid-state reaction and identified by X-ray diffraction. We adopted the Rietveld refinement approach and Diamond software to calculate the bottleneck size of the ion channel. The XRD pattern showed that nearly a single phase could be obtained for NaZr2(PO4)3, Na2Zr2SiP2O12, Na3Zr2Si2PO12, KZr2(PO4)3, and partial solid-solution could be obtained for Na0.5K0.5Zr2(PO4)3 through calcined at two-stage 600℃/6 h-1000℃/12 h. Adopting the same condition of calcination, Na3-xKxZr2Si2PO12 (x=3, 1, 0.5, 0.1, 0.05) solid-solution would not be formed and have several phases. Powders for NASICON compound was formed into a pellet with uniaxial compression. NaZr2(PO4)3, Na0.5K0.5Zr2(PO4)3, KZr2(PO4)3 was sintered at 1200℃/10 h contains 2wt% MgO and Na2Zr2SiP2O12, Na3Zr2Si2PO12 at 1250℃/10 h to obtain a relative density > 90%. The electrical conductivity of the ceramic body is measured with direct current analysis. We found that the ionic conductivity in room temperature of MZr2(PO4), (M=Na, Na0.5K0.5, K) is negatively related to the bottleneck size. Higher K+ content broadens the bottleneck size, but decreased the ionic conductivity. The room temperature ionic conductivity of Na1+xZr2SixP3-xO12 (x=0, 1, 2) is positively related to the bottleneck size. Higher Si4+ content broadens the bottleneck size and increased ionic conductivity.

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