Effects of high-energy milling on the solid-state synthesis of pure nano-sized Li4Ti5O12 for high power lithium battery applications

Li₄Ti₅O₁₂ was synthesized from Li₂CO₃ and anatase TiO₂ using different degree of milling to test the hypothesis that finer starting materials can result in a smaller Li₄Ti₅O₁₂ particle size and better high-rate discharging capacities. The degree of milling was controlled using three different ZrO₂ media sizes for 3 hours of high-energy milling, whereas 5 mm balls were used for 24 hours ball milling. High-energy milling produced significantly finer starting materials and Li₄Ti₅O₁₂ particles compared to those produced by ball milling. Among the three different balls used in high-energy milling, the 0.10 mm media showed the most favorable results. Pure Li₄Ti₅O₁₂ with a mean particle size of 146 and 175 nm were synthesized by an economic solid-state reaction combined with high-energy milling using 0.05 and 0.10 mm beads, respectively. These pure nano-sized Li₄Ti₅O₁₂ exhibited a much higher specific capacity and superior rate capability than those of coarse rutile TiO₂-contained Li₄Ti₅O₁₂ particles.