Bismuth layer-structured ferroelectrics with high Curie temperatures have recently attracted significant attention as promising candidates for high-temperature piezoelectric applications. However, the conventional solid-state reaction method entails high-temperature processing that induces bismuth volatilization, thereby degrading device reliability. In this study, we employed a co-precipitation method enabling atomic-level mixing to significantly lower the synthesis temperature of Nb/Tadoped Bi₄Ti₃O₁₂ ceramics compared to the solid-state reaction method. Experimental results demonstrated that the coprecipitation method yielded a pure single phase at 600℃ without intermediate phases. Furthermore, the synthesized nanopowders, with an average size of 100 nm, lowered the onset temperature of sintering shrinkage to 650℃, approximately 200℃ lower than that of the solid-state counterpart. The low-temperature synthesis process proposed in this work is expected to contribute to the performance enhancement of high-temperature piezoelectric devices by effectively suppressing bismuth volatilization and ensuring compositional stability.

Ni-rich cathode materials have been developed as the most promising candidates for next-generation cathode materials for lithium-ion batteries because of their high capacity and energy density. In particular, the electrochemical performance of lithium-ion batteries could be enhanced by increasing the contents of nickel ion. However, there are still limitations, such as low structural stability, cation mixing, low capacity retention and poor rate capability. Herein, we have successfully developed the nanorod-type Ni-rich cathode materials by using co-precipitation method. Particularly, the nanorod-type primary particles of LiNi_0.7Co_0.15Mn_0.15O₂ could facilitate the electron transfer because of their longitudinal morphology. Moreover, there were holes at the center of secondary particles, resulting in high permeability of the electrolyte. Lithium-ion batteries using the prepared nanorod-type LiNi_0.7Co_0.15Mn_0.15O₂ achieved highly improved electrochemical performance with a superior rate capability during battery cycling.

Citations

• Thermal Stability of NCM622 Cathode Material for Li-ion Batteries: A Real-time Synchrotron X-ray Scattering Study
  Seung-Han Lee, Tae-Sik Cho
  Journal of Electrical and Electronic Materials.2026; 39(4): 394.     CrossRef