Aqueous Synthesized Nanostructured Li4Ti5O12 for High-Performance Lithium Ion Battery Anodes.

Nanostructured Li₄Ti₅O₁₂ (LTO) was prepared via a novel process comprising low-temperature (<100°C) aqueous synthesis and annealing of the hydrous intermediate phase Li_1.81H_0.19Ti₂O₅·2H₂O (LTH) using only LiOH and TiCl₄ as precursors. Nanosheet-structured LTH converted to either LTO nanosheets (102 m²·g^-1) or LTO nanoparticles (28 m²·g^-1) upon annealing at 400 and 600°C respectively, each exhibiting unique electrochemical performance properties. The nanosheet-structured LTO exhibited higher initial charge capacity (228.3 vs. 187.3 mAh ·g^-1 at 1.0 V cutoff and C/24 rate) than the nanoparticle-structured LTO. Furthermore, the LTO nanosheets taking advantage of their short diffusion path exhibited better rate capability than the LTO nanoparticles; for example their discharge capacity at 15 C was 115 mAh ·g^-1 vs. 68.4 mAh ·g^-1 at 1.2 V cutoff for the LTO nanoparticles. Meanwhile, the LTO nanoparticles exhibited better cyclability than the LTO nanosheets because of their higher crystallinity. Thus after 130 1 C cycles with cut off at 1.2 V (vs. Li/Li⁺), the discharge capacity of the nanosheets was 132.9 mAh ·g^-1 while that of nanoparticles was 150.7 mAh ·g^-1, corresponding to 85 and 97% discharge capacity retention respectively. The newly synthesized nanostructured LTO material can offer a low cost scalable solution for high-performance LIB anodes. [ABSTRACT FROM AUTHOR]