Shape-controlled synthesis of Ti 4O 7 nanostructures under solvothermal-assisted heat treatment and its application in lithium-sulfur batteries

摘要

AbstractHere we report a facile approach to synthesize a series of pure Ti4O7nanostructures via solvothermal process and subsequent thermal treatment. The one-dimensional of Ti4O7nanorods (1D Ti4O7NRs) and three-dimensional of Ti4O7nanoparticles (3D Ti4O7NPs) were successfully achieved and investigated well by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HR-TEM), and Brunauer-Emmett-Teller analysis (BET). The as-prepared Ti4O7nanostructures were used as additive to prepare Ti4O7/sulfur composite cathodes. The initial discharge capacity of the sulfur cathode with the added Ti4O7NRs was 1050?mAh g?1, and remaining capacity was 580?mAh g?1after 300 cycles at 1C. Even at a high current density of 2C, it also kept at a high discharge capacity of 590?mAh g?1. Compared with Ti4O7NPs/sulfur electrode, the electrodes containing Ti4O7NRs show the excellent cycling and rate performance, confirming that the morphology of Ti4O7could effectively influence its electrochemical performance for lithium sulfur batteries. The good electrochemical properties of Ti4O7NRs can be attributed to the higher catalytic activity in the lithium-sulfur redox reaction, the lower charge-transfer resistance and larger lithium ion diffusion coefficient.Graphical abstractDisplay OmittedHighlights?1D and 3D nanostructures of electrically-conductive oxide Ti4O7are constructed as sulfur hosts.?The morphology of Ti4O7effectively influences its electrochemical performance for Li-S battery.?The Ti4O7NRs/sulfur keeps a discharge capacity of 580?mAh g?1after 300 cycles at 1C.]]>