The Microfluidic Method Is a Potential Choice in the Preparation of NASICON-type LATP Solid Electrolyte

The NASICON-type LATP (Li-Al-Ti-P-O) solid electrolytes possess good ion conductivity and high thermal stability, making them one of the most promising solid electrolytes for developing organic–inorganic composite solid electrolytes, especially the LATP@PEO (polyethylene oxide) composite solid electrolytes. At present, traditional coprecipitation methods are commonly used to prepare LATP. However, the LATP solid electrolytes prepared by this method possess low purity and crystallinity, multiple impurities, and difficulty in controlling grain size and morphology. These seriously restrict the improvement of ion conductivity of LATP@PEO composite solid electrolytes. Based on this, in this work, LATP was prepared by a continuous microfluidic coprecipitation method. Compared with the traditional coprecipitation method, the crystallinity of LATP obtained by the continuous microfluidic coprecipitation method was higher and the particle size dispersion was more uniform. Furthermore, it has been found that LATP@PEO composite solid electrolytes with high ionic conductivity (1.23 × 10^-5 S cm^-1) and low impedance (470 Ω) were obtained through a solution pouring method. The results show that the LATP obtained by continuous microfluidic coprecipitation is more conducive to improving the ionic conductivity and reducing the impedance of the LATP@PEO composite solid electrolytes than the LATP obtained by the traditional coprecipitation method. This finding suggests that the continuous microfluidic coprecipitation method would be the potential choice to prepare LATP solid electrolytes, and it possesses great prospects of industrial applications in the future.