Analysis of Pore Characteristics of Solid-State Electrolytes Based on Terahertz Time-Domain Spectroscopy

Inorganic solid-state electrolytes have become a focal point in the research of next-generation energy storage technologies due to their high safety and potential for high energy density. Pore characteristics play a crucial role in influencing ionic transport and mechanical properties, making their efficient and precise characterization essential. However, traditional pore testing methods continue to encounter challenges in providing rapid and non-destructive measurements. Therefore, this study proposes a non-destructive and rapid characterization method for pore characteristics based on terahertz time-domain spectroscopy. This approach, combined with the effective medium theory, investigates the impact of sintering temperature on the microstructural pore characteristics of Li6.4La3Zr1.4Ta0.6O12 based on optical constants measured in the terahertz frequencies. Notably, the study introduces the structural parameter Sa for characterizing solid electrolyte materials, providing insights into the geometric configuration and directional distribution of the microstructural pore architecture. The testing method proposed in this research not only enhances the accuracy of porosity measurements in solid-state electrolytes, but also provides insights into the microstructural characteristics of pores. This contributes an effective tool for understanding the pore characteristics of inorganic solid-state electrolytes and expands the application potential of terahertz time-domain spectroscopy in materials science.