Ellipsoid-like Li₄Ti₅O₁₂–TiO₂ composites constructed by nanocrystals for lithium ion batteries

Abstract

Porous ellipsoid-like Li4Ti5O12–TiO2 composites with a unique micro/nano structure have been successfully fabricated via a facile sol–gel route followed by calcination.

Single particle structure characterization of solid-state synthesized Li4Ti5O12

“…This particle has rather specific shape and looks divided into two equal parts, shifted a little bit, and fused together again. Two-composition single particles were shown previously by HRTEM [46,[50][51][52][53][54][55][56] , so we can propose that they are rather common, but interface between two phases/compounds is expected to be mechanically unstable thus leading to particle disruption into two smaller singlecomposition particles during solid-state synthesis. Also some particles with Raman spectra attributed to single-composition particles can indeed have some small inclusions of other compositions, which were not detected during Raman spectra analysis.…”

The novel and facile preparation of multilayer MoS2 crystals by a chelation-assisted sol–gel method and their electrochemical performance

“…33,34 The medium-frequency semicircle corresponds to the charge-transfer resistance R ct and CPE 2 of the electrode/electrolyte interface. 35,36 The inclined line is assigned to the lithium-diffusion within the electrode material. 37 According to EIS equivalent circuit in Fig.…”

Solvothermal synthesis method for dual-phase Li4Ti5O12/TiO2 composites for high-stability lithium storage

“…The LTO/ TO exhibits two pairs of cathodic/anodic peaks at 1.5/1.6 V and 1.7/2.0 V, while the LTO has an additional pair of redox peaks located at 1.5/1.6 V, which corresponds to the typical charge and discharge plateau for Li + intercalation and removal in Li 4 Ti 5 O 12 (equation (1)). This weak peak at 1.7/2.0 V indicates the redox reactions of the Ti 4+ /Ti 3+ couple in TiO 2 (equation (2)) [24,25]. The dQ/dV curves correspond well with the first charge/discharge diagram.…”

“…Evidently, the charge-transfer resistances of the LTO/TO are lower than those of LTO. This suggests that the grain boundary and phase interfaces of Li 4 Ti 5 O 12 can be enriched by the incorporation of TiO 2 , which can effectively improve the electrochemical performance [22,24]. Two-phase LTO/TO sample has excellent electrochemical properties.…”