In the realm of energy storage, a team of researchers from the University of Science and Technology Beijing, led by Professor Shuiqing Li, has made a significant stride in enhancing the performance of solid electrolytes for all-solid-state sodium batteries. Their work, published in the journal Advanced Energy Materials, focuses on improving the ionic conductivity of NASICON-structured Na3Zr2Si2PO12, a promising candidate for solid electrolytes in next-generation energy storage technologies.
The researchers employed a novel approach using swirling spray flame synthesis to produce Mg-doped NASICON solid electrolyte nanoparticles. This method allows for efficient doping and homogeneous mixing, which is crucial for scalable production. The flame synthesis process results in core-shell non-NASICON structures with nano-scale high-entropy mixing. One of the key advantages of this technique is the significant reduction in atomic migration distances compared to conventional solid-state reactions. This enables reactive sintering to preserve the high sinterability of nanoparticles during post-treatment processes.
High-temperature sintering yields dense NASICON-structured solid electrolytes. Among the samples, Mg0.25NZSP exhibited an optimal ionic conductivity of 1.91 mS/cm at room temperature and an activation energy of 0.200 eV. The enhancement mechanism can be attributed to two main factors: the incorporation of Mg into the NASICON phase and the formation of a secondary phase. The low-melting-point secondary phase significantly improves grain boundary contact, thereby enhancing grain boundary conductivity. This process achieves simultaneous enhancement of both bulk and grain boundary conduction through a single-step procedure.
Comparative analysis of sintering temperatures and ionic conductivities among NASICON solid electrolytes synthesized via different methods demonstrates that flame-synthesized nanoparticles offer superior performance and reduced post-treatment costs. This is due to their exceptional nano-scale sinterability and uniform elemental distribution. The practical applications for the energy sector are substantial, as improved ionic conductivity in solid electrolytes can lead to more efficient and safer energy storage solutions. This research brings us one step closer to realizing the full potential of all-solid-state sodium batteries, which promise cost-effectiveness and enhanced safety compared to traditional lithium-ion batteries.
Source: Advanced Energy Materials, “Synergetic Enhancement on Bulk and Grain Boundary Ionic Conduction of Mg Doped High-Entropy NASICON-Type Solid Electrolyte for Solid-State Na+ Batteries by Spray Flame Synthesis” by Tianyi Wu, Yiyang Zhang, Zhu Fang, Shuting Lei, Xing Jin, and Shuiqing Li.
This article is based on research available at arXiv.