For many solid electrolytes, the introduction of structural disorder is beneficial for the ionic conductivity, since it breaks the localisation of the mobile species. Yet, in the case of the Na⁺ superionic conductor (NASICON) structure, we show that an ordered configuration of the cations can both diminish or escalate the ionic conductivity. Here, the key factor is the arrangement of the P⁵⁺ ions with respect to the sodium diffusion channels. Engineering this factor, NASICON can be tuned from a poor, two-dimensional conductor to a superionic, three-dimensional conductor. Since experimentally only general Si/P lattice positions can be determined, the distribution of P⁵⁺ in current samples is not known. Based on our calculations of conductivities and activation energies, we conclude that experimental samples possess no long-range cation order yet. Consequentially, we propose that NASICON type materials have not been utilised to their fullest extend. By tailoring their cation order, an increase in ionic conductivity of nearly a factor of four can be enabled. Supporting this statement, we present a systematic study on the influence of cation order on the tracer diffusion coefficient D_tr, the sodium diffusion pathways, the charge diffusion coefficient D_σ, the ionic conductivity σ, the Haven ratio H_R and the activation energy E_A obtained by Molecular Dynamics simulations.

对于许多固体电解质，结构紊乱的引入有利于离子电导率，因为它破坏了流动物质的定位。但是，在Na ⁺超离子导体（NASICON）结构的情况下，我们显示出阳离子的有序构型可以减小或增大离子电导率。在此，关键因素是P ⁵⁺离子相对于钠扩散通道的排列。通过设计此因素，可以将NASICON从不良的二维导体调整为超离子的三维导体。由于实验上只能确定一般的Si / P晶格位置，因此P ⁵⁺的分布目前样品中的未知数。根据我们对电导率和活化能的计算，我们得出结论，实验样品尚不具有长距离阳离子序。因此，我们建议尚未充分利用NASICON型材料。通过调整其阳离子顺序，可以使离子电导率提高近四倍。支持这一声明，我们提出了一个系统的研究上阳离子为了对影响的示踪弥散系数d _TR，钠扩散途径，电荷扩散系数d _σ，离子电导率σ，所述黑文比ħ _ř和活化能È_一个 通过分子动力学模拟获得。