Insight into the formation mechanism of Li4Ti5O12 microspheres obtained by a CTAB-assisted synthetic method and their electrochemical performances

摘要: Porous Li4Ti5O12 (LTO) microspheres consisting of a stack primary nano-crystalline grains were prepared by adding dropwise LiOH solution into tetrabutyl titanate (TBT)/cetyltrimethylammonium bromide (CTAB) glycol solution, followed hydrothermal synthesis and further calcination. In order to understand the formation mechanism LTO microspheres, effects cationic species pH on hydrolysis TBT in TBT/CTAB/LiOH studied first using NaOH, KOH LiCl as substitutes for solution. Furthermore, study effect CTAB, morphology microstructure products calcined from TBT/LiOH characterized scanning electron microscopy, high-resolution transmission microscopy X-ray diffraction. The results indicate that strong basicity existence CTAB are two necessary factors microspheres. spinel obtained porous because loose stacking grains. structure is beneficial improvement contact surface area between electrode electrolyte, quick diffusion electrons ions. Therefore, exhibit excellent electrochemical performance. specific capacities at 10C, 20C, 30C, 40C, 50C 60C up 177, 175, 170, 165, 158 157 mA h g−1, respectively. When current density returns discharge capacity 10C; moreover, retention reaches 93% after 500 cycles.