Wang Xue, Xu Xuele, Li Yuxiang, Chen Wenqian, Zhao Guowei, Wang Heng, Tang Ya, Wu Pengcheng, Tang Liang
Key Laboratory of Organic Compound Pollution Control Engineering (MOE), School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Road, Shanghai 200444, China.
Department of Chemistry, College of Sciences, Shanghai University, No. 99, Shangda Road, Shanghai 200444, China.
ACS Omega. 2024 Mar 5;9(11):13051-13058. doi: 10.1021/acsomega.3c09500. eCollection 2024 Mar 19.
The sodium-rich solid electrolyte, NaSOF (NSOF), holds promise for eco-friendly and resource-abundant energy storage. While the introduction of heterovalent dopants has the potential to enhance its suitability for battery applications by creating Na vacancies, the effect of vacancies and sodium concentrations on sodium conduction remains unclear. In this work, Mg was introduced into Na sites in NaSOF, generating sodium vacancies with different contents by using solid-state synthesis method. Among the resulting materials, NaMgSOF exhibited an ionic conductivity that is two-order-of-magnitude higher than NSOF at 298 K. Notably, as the sodium concentration decreased, the ionic conductivity also declined, revealing an equilibrium between Na vacancies and concentrations. To further investigate the influence of sodium concentration, excess Na was introduced into NaMgSOF, which inherently possesses a lower sodium content by using solid-state synthesis method. However, this adjustment only led to an approximately one-order-of-magnitude enhancement in optimal ionic conductivity at 298 K. Combined with an X-ray diffraction analysis, our findings underscore the greater sensitivity of sodium conduction to variations in sodium vacancies. This study paves the way for the development of ultrafast sodium ion conductors, offering exciting prospects for advanced energy storage solutions.
富含钠的固体电解质NaSOF（NSOF）在环保且资源丰富的能量存储方面颇具潜力。虽然引入异价掺杂剂有可能通过产生钠空位来提高其在电池应用中的适用性，但空位和钠浓度对钠传导的影响仍不明确。在这项工作中，将镁引入到NaSOF的钠位点中，通过固态合成方法产生了不同含量的钠空位。在所得材料中，NaMgSOF在298 K时表现出比NSOF高两个数量级的离子电导率。值得注意的是，随着钠浓度降低，离子电导率也下降，这揭示了钠空位与浓度之间的平衡。为了进一步研究钠浓度的影响，通过固态合成方法将过量的钠引入到本身钠含量较低的NaMgSOF中。然而，这种调整仅使298 K时的最佳离子电导率提高了约一个数量级。结合X射线衍射分析，我们的研究结果强调了钠传导对钠空位变化的更高敏感性。这项研究为超快钠离子导体的开发铺平了道路，为先进的能量存储解决方案提供了令人兴奋的前景。
