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

Abstract

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.