Colloidal TiO2 solid spheres as high-performance anodes for Lithium-ion batteries: Synthesis, characterization, and optimization

Anatase phase TiO2 nanoparticles were successfully synthesized by annealing amorphous colloidal TiO2 spheres. The colloidal TiO2 nanoparticles exhibited enhanced specific discharge capacities similar to 296 (0.1C), 185 (1C), 127 (2C), 101 (5C) and 82 mAh g(-1) (10C) in contrast to their amorphous counterparts similar to 182 (0.1C), 119 (1C), 81 (2 C), 43 (5 C) and 18 mAh g(-1) (similar to 10C rates). Amorphous TiO2 nanoparticles developed a layer of solid electrolyte interface (SEI) comprising lithium carbonate, lithium alkyl carbonates, and organic phosphates, leading to heightened intrinsic resistance of cells and diminished performance in terms of rate and cycling. Conversely, annealing at high temperatures effectively eliminates chemisorbed water and hydroxyl groups, resulting in improved stability under varying rates and during cycling for lithium-ion batteries based on titanium dioxide. The annealed colloidal TiO2 demonstrated notably elevated specific discharge capacities and capacity retention of 93.5 % compared to amorphous titanium dioxide spheres of 42.1 %.