Solid-state ion doping and crystal structure engineering for enhanced ionic conductivity in LiTi2(PO4)3 electrolytes

NASICON-type LiTi2(PO4)(3) (LTP) are gaining enormous attention for applications in solid-state lithium-ion batteries due to its comparatively high conductivities and three-dimensional open-framework. The selective substitution strategies at cationic sites are regarded as an important approach to enhance the ionic conductivity of LTP electrolytes. Present work reports the influence of Ga3+ ions doping on the crystal structure, density, activation energy, and ionic conductivity of Li1+xGaxTi2-x(PO4)(3) (x = 0, x = 0.25, x = 0.5, x = 0.75 and x = 1, labeled as LGTP) electrolytes. Herein, we found that the relative density, activation energy, and conductivity of LGTP electrolytes show a tendency to increase first and then decrease as Ga3+ doping increases. The sample with x = 0.5 exhibits the highest ionic conductivity (4.64 x 10(-4) S cm(-1)), the highest relative density (96.21%), and the lowest activation energy (0.17 eV). The conductivity of Li1.5Ga0.5Ti1.5(PO4)(3) (LGTP050) increases by three orders of magnitude when compared to LTP without Ga3+ doping, possibly due to its high relative density, low activation energy, and high lithium-ion concentration. These findings suggest that doping LTP ceramic electrolytes with Ga3+ can significantly improve conductivity.

Automated summary

This study investigates the influence of Ga3+ ion doping on the crystal structure, density, activation energy, and ionic conductivity of LTP electrolytes. The results show that the relative density, activation energy, and conductivity of LGTP electrolytes increase first and then decrease as Ga3+ doping increases, with the sample containing x = 0.5 exhibiting the highest ionic conductivity. These findings suggest that doping LTP ceramic electrolytes with Ga3+ can significantly improve conductivity.