Synthesis, Structure and Electronic Properties of Li₄Ti₅O₁₂ Anode Material for Lithium Ion Batteries

Abstract

Nanosized spinel Li4Ti5O12 was successfully synthesized by a solid state reaction method at 800°C according to the Li4Ti5O12cubic spinel phase structure. In this synthesizing process, anatase TiO2and Li2CO3were used as reactants. The average grain size of the synthesized powders was around 200 nm. The synthesized Li4Ti5O12powder was characterized X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectrometry (EDS), and Specific Surface Area Analyzer (BET, Brunner-Emmett-Teller) respectively. X-ray diffraction results show that calcination temperature and time have the important effects on the crystal structure of Li4Ti5O12powder. In this study, we used a first principle method, based on the density functional theory to explore electronic and structural properties of Li4Ti5O12, as anode material for lithium ion batteries. Differences on these properties between delithiation state Li4Ti5O12and lithiation state Li7Ti5O12are compared. All the predicted structural and electrochemical properties agree closely with the experimental findings in literature. The average intercalation voltage of 1.4V during charging/discharging were obtained. We have shown that the Li4Ti5O12material exhibits insulating behavior with the band gap of 3.16 and 3.90 eV using the GGA and GGA+U+J0calculations respectively. Li7Ti5O12becomes metallic as Li atoms inserted in Li4Ti5O12material. Spinel Li4Ti5O12has been regarded as an attractive anode material for the development of high-power lithium-ion batteries because of its unique attributes of high safety and rate capability.

Electrochromic Behavior and Phase Transformation in Li4+xTi5O12 upon Lithium-Ion Deintercalation/Intercalation

“…In 2010, Yu et al confirmed this electrochromic switching of LTO by depositing thin films on a transparent conductive oxide using pulsed laser evaporation . The same behavior was confirmed experimentally by others as well. , These observations are in general agreement with the electronic structure of the material − because Li 4 Ti 5 O 12 is observed as an insulator (hence should be transparent in the visible region of light due to wide band gap), whereas Li 7 Ti 5 O 12 shows metallic conductivity. However, the quantitative description of the electrochromic behavior [or the complex refractive index (CRI)] with the band structure of the material is still missing.…”

“…(a) Extinction coefficient and (b) real part of the CRI as extracted from the model traces, as shown in Figure b; (c) change of the first resonance [higher energy, corresponding to the first maxima in (a)] with the state of charge in the LTO electrode, the red dashed line represents a cubic spline interpolation of the measurement points; (d) total density of states of Li 4 Ti 5 O 12 and Li 7 Ti 5 O 12 …”

Azo‐Group‐Containing Organic Compounds as Electrode Materials in Full‐Cell Lithium‐Ion Batteries

“…The peaks are calibrated by the C−C peak at 284.7 eV in C 1s spectrum. The Li 1s XPS spectrum of pristine ADL electrode in LFP/ADL full‐cells exhibited an obvious characteristic peak at 53.48 eV, corresponding to Li−O bond due to the presence of lithium carboxylate in ADL (Figure a), which displayed a little deviation around at ∼53.62 eV with the charging voltage increase . The peak, located at ∼54.47 eV, represented the formation of a lithiated azo group (Li‐N−N‐Li) due to the electrochemical insertion of Li‐ions into azo N=N group .…”

Structural and electronic properties of the spinel Li₄Ti₅O₁₂

“…The LTO was prepared by solid state reaction method. The raw materials TiO 2 (99.9 %, Sigma Aldrich) and Li 2 CO 3 (99.9 %, Sigma Aldrich) were mixed by ball milling for 24 h and then calcined at 800 °C for 2 h in the air in the same technique as described in our previous investigation [25]. The powder X-ray diffraction (XRD) data of the sample was collected on a Maxima-X7000 diffractometer for the diffraction angles between 100 and 900 with the increment of 0.020.…”