Y-doped Li4Ti5-xYxO12 with Y2Ti2O7 surface modification anode materials: Superior rate capability and ultra long cyclability for half/full lithium-ion batteries

Li4Ti5O12 (LTO) anode materials have attracted attention owing to its structural stability and negligible volume change. However, its application is still restricted due to the low conductivity and Li+ diffusion coefficient. To address these disadvantages, herein, Y3+ doped Li4Ti5-xYxO12 (LYTO) with Y2Ti2O7 surface modification anode materials have been synthesized by an easy solid-state reaction with ball milling activating method using Y(NO3)(3) as the dopant. The structural analysis shows that Y3+ doping does not change the crystal structure of LTO and exhibits a uniform particle size distribution. When applied to the anodes of lithium ion batteries, Li4Ti4.8Y0.2O12 possess outstanding long-cycle stability and excellent rate performance. The discharge specific capacity achieves 173 mAh g(-1) after 300 cycles at a current density of 1 A g(-1) and the voltage range of 1-3 V and 92 mAh g(-1) after 1000 cycles at the current density of 7 A g(-1) (40C), respectively. In addition, full cells are assembled using Li4Ti4.8Y0.2O12 as anodes and LiCoO2 as cathodes. The specific capacity of coin full cell remains 150 mAh g(-1) after 100 cycles at 0.2C, while the pouch full cell exhibits 149 mAh g(-1) under the same conditions. These results clearly confirm that LYTO can be considered as a promising electrode material for high performance lithium-ion batteries. (C) 2020 Elsevier B.V. All rights reserved.