Mixed-Surfactant-Assisted Synthesis of Dual-Phase Li₄ Ti₅ O₁₂ -TiO₂ Hierarchical Microspheres as High-Performance...

A mixed-surfactant-assisted method was developed to synthesize dual-phase Li₄ Ti₅ O₁₂ -TiO₂ hierarchical microspheres. The ratio of anionic/cationic surfactant could regulate the primary structure morphology and the dual-phase ratio of the final product, in which the primary structure morphology could be stacked nanosheets, small nanoparticles, or large nanoparticles. The sample with a primary structure morphology of small nanoparticles had the highest specific surface area of 79.38 m²  g^-1 and the best electrochemical performance because of its high Li⁺ migration rate, low polarization, and appropriate TiO₂ content. Its capacity reached 153.5 mA h g^-1 at a current rate of 40 C, and it retained nearly 100 % of its capacity after 100 cycles. A self-assembly mechanism of the mixed surfactant was highlighted to explain the formation of hierarchical microspheres. The physical and electrochemical properties of obtained material were correlated effectively.