An ultrathin and continuous Li4Ti5O12 coated carbon nanofiber interlayer for high rate lithium sulfur battery

Severe capacity fading and poor high rate performance of lithium sulfur (Li-S) battery caused by shuttle effect and low conductivity of sulfur hampers its further developments and applications. Li4Ti5O12 (LTO) possesses high lithium ion conductivity, and it is also can be used as an active adsorbent for polysulfide. Herein, fine LTO particle coated carbon nanofibers (CNF) were prepared and a conductive network both for electron and lithium ion was built, which can greatly promote the electrochemical conversion of polysulfide and improve the rate performance of Li-S batteries. Meanwhile, a quantity of adsorption sites is constructed by defects of the surface of LTO-CNF membrane to effectively immobilize polysulfide. The multifunctional LTO-CNF interlayer could impede the shuttle effect and enhance comprehensive electrochemical performance of Li-S batteries, especially high rate performance. With such LTO-CNF interlayer, the Li-S battery presents a specific capacity of 641.9 mAh/g at 5C rate. After 400 cycles at 1 C, a capacity of 618.0 mAh/g is retained. This work provides a feasible strategy to achieve high performance of Li-S battery for practical utilization. (C) 2018 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.