Design of Bronze-Rich Dual-Phasic TiO2 Embedded Amorphous Carbon Nanocomposites Derived from Ti-Metal-Organic Frameworks for Improved Lithium-Ion Storage

Dual-phasic (DP)-TiO2-based composites are considered attractive anode materials for high lithium-ion storage because of the synergetic contribution from dual-phases in lithium-ion storage. However, a comprehensive investigation on more efficient architectures and platforms is necessary to develop lithium-storage devices with high-rate capability and long-term stability. Herein, for the first time, a rationally designed bronze-rich DP-TiO2-embedded amorphous carbon nanoarchitecture, denoted as DP-TiO2@C, from sacrificial Ti-metal-organic frameworks (Ti-MOFs) via a two-step pyrolysis process is proposed. The bronze/anatase DP-TiO2@C nanocomposites are successfully synthesized using a unique pyrolysis process, which decomposes individually the metal clusters and organic linkers of Ti-MOFs. DP-TiO2@C exhibits a significantly high density and even distribution of nanoparticles (<5 nm), enabling the formation of numerous heterointerfaces. Remarkably, the bronze-rich DP-TiO2@C shows high specific capacities of 638 and 194 mAh g(-1) at current densities of 0.1 and 5 A g(-1), respectively, owing to the contribution of the synergetic interfacial structure. In addition, reversible specific capacities are observed at a high rate (5 A g(-1)) during 6000 cycles. Thus, this study presents a new approach for the synthesis of DP-TiO2@C nanocomposites from a sacrificial Ti-MOF and provides insights into the efficient control of the volume ratio in DP-TiO2 anode architecture.

Automated summary

A bronze-rich dual-phasic TiO2-embedded amorphous carbon nanoarchitecture, DP-TiO2@C, was synthesized for the first time using sacrificial Ti-metal-organic frameworks. This material exhibits high specific capacities and high-rate capability, as well as long-term stability and even distribution of nanoparticles.