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

• Published in: Journal of alloys and compounds 2020-09, Vol.835, p.155327, Article 155327
• Main Authors: Chen, Wenyan, Kuang, Shaojie, Liu, Zuotao, Fu, Haikuo, Yun, Qiyang, Xu, Dexiang, Hu, Hang, Yu, Xiaoyuan
• Format: Article
• Language: English
• Subjects: Anodes; Ball milling; Crystal structure; Current density; Diffusion coefficient; Electrochemical performance; Electrode materials; Li4Ti5O12 anode; Lithium; Lithium ion battery; Lithium-ion batteries; Long cycle; Low conductivity; Particle size distribution; Rechargeable batteries; Structural analysis; Structural stability; Y3+ doping
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.155327

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. [Display omitted] •Y3+ doped Li4Ti5-xYxO12 with Y2Ti2O7 surface modification have been synthesized.•Li4Ti5-xYxO12 anodes in half-cells possess superior rate capability and ultra-long life.•Y20 anodes exhibit a prominent full cell performances.