A comparative study of increased lithium storage with low resistance at structural defects in amorphous titanium dioxide electrode

Abstract

Various studies are conducted with an aim to increase the capacity and reduce of the lithium diffu-sion resistance during the charge/discharge of titanium oxide (TiO2), which is used as anode material in lithium-ion batteries. However, it is difficult to overcome the limited storage capacity and high dif-fusion resistance because of the intrinsic crystalline features of TiO2. This study demonstrates that the lithium storage limit and high lithium diffusion resistance of crystalline titanium oxide (c-TiO2) can be overcome by using amorphous titanium oxide (a-TiO2). The results of X-ray diffraction, X-ray absorp-tion spectroscopy, and galvanostatic intermittent titration show that a-TiO2 can store more Li-ions and has a reduced lithium diffusion resistance than c-TiO2. In contrast, the lithium storage of the crystalline structure is limited and its lithium diffusion resistance is high. The better performance of a-TiO2 can be ascribed to anomalous amorphous lithium storage sites, which provide additional lithium storage and open lithium diffusion paths. (C) 2021 Elsevier Ltd. All rights reserved.