0013-4651/2013/160(5)/A3041/7/$31.00 © The Electrochemical Society JES FOCUS ISSUE ON INTERCALATION COMPOUNDS FOR RECHARGEABLE BATTERIES 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 Li1.81H0.19Ti2O5 · 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