Pomegranate-like C@TiO2 mesoporous honeycomb spheres have been synthesized through two simple steps: formation of TiO2 mesoporous honeycomb spheres and the coating of polypyrrole followed by carbonization. TiO2 mesoporous honeycomb spheres are of large specific surface area of 153 m2 g−1 and contain abundant mesopores, which leads to high electrochemical activity and good kinetic performance of TiO2. A layer of amorphous carbon shell with the thickness of 30–40 nm tightly encapsulates a TiO2 mesoporous honeycomb sphere, forming a novel pomegranate-like small sphere, which significantly improves electronic conductivity and structural stability of TiO2. Benefiting from the unique pomegranate-like structure, C@TiO2 mesoporous honeycomb spheres exhibit high specific capacity, stable long-term cycling performance and good rate capability as an anode material for lithium ion batteries (LIBs). After 500 cycles at 1 C, the discharge capacity still reaches 184 mAh g−1. The electrochemical performance is superior to pure TiO2 mesoporous honeycomb spheres and most of the reported high-performance TiO2-based composites. This work provides a new high-performance TiO2-carbon-based composite material for LIBs as well as a new valuable research strategy.
High-porosity mesoporous framework structures are attractive for electrochemical energy storage and other applications. Herein we demonstrate a novel synthesis strategy to make zeolitic imidazolate framework-67 oxidize to a Co3O4 three-dimensional mesoporous framework structure. This strategy relies on the oxygen-limitation effect of the closed nanocage and the affinity effect of polyvinylpyrrolidone towards zeolitic imidazolate framework-67. Several TiO2 nanospheres, as the unique structure junctions, are uniformly embedded within the Co3O4 framework to enhance the framework strength. The TiO2/hydrous titania polyhedron nanocage, as the protecting shell, further encapsulates the Co3O4 framework, forming a perfect capsule-type hybrid. As anode materials for lithium-ion batteries, TiO2@Co3O4 framework capsules show superior lithium storage performance with high reversible capacity, stable cycling life and good rate capability. A reversible capacity of 1042 mAh g−1 can be delivered after 200 cycles at a current density of 300 mA g−1. The average discharge capacity over 200 cycles reaches 926 mAh g−1. This demonstrates the superiority of this material structure and its great potential as an anode for high-performance lithium-ion batteries. This work indicates a new strategy to take advantage of metal-organic frameworks to synthesize their mesoporous framework derivatives.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.