Solvent‐Free Synthesis of Uniform MOF Shell‐Derived Carbon Confined SnO₂/Co Nanocubes for Highly Reversible Lithium Storage

Abstract

Tin dioxide (SnO ) has attracted much attention in lithium-ion batteries (LIBs) due to its abundant source, low cost, and high theoretical capacity. However, the large volume variation, irreversible conversion reaction limit its further practical application in next-generation LIBs. Here, a novel solvent-free approach to construct uniform metal-organic framework (MOF) shell-derived carbon confined SnO /Co (SnO /Co@C) nanocubes via a two-step heat treatment is developed. In particular, MOF-coated CoSnO hollow nanocubes are for the first time synthesized as the intermediate product by an extremely simple thermal solid-phase reaction, which is further developed as a general strategy to successfully obtain other uniform MOF-coated metal oxides. The as-synthesized SnO /Co@C nanocubes, when tested as LIB anodes, exhibit a highly reversible discharge capacity of 800 mAh g after 100 cycles at 200 mA g and excellent cycling stability with a retained capacity of 400 mAh g after 1800 cycles at 5 A g . The experimental analyses demonstrate that these excellent performances are mainly ascribed to the delicate structure and a synergistic effect between Co and SnO . This facile synthetic approach will greatly contribute to the development of functional metal oxide-based and MOF-assisted nanostructures in many frontier applications.

Applications of Metal–Organic‐Framework‐Derived Carbon Materials

“…After 500 cycles, large reversible capacities of 734, 591, and 505 mA h g −1 were still remained at 1, 2, and 5 A g −1 , respectively. Later, a brand solvent‐free approach was designed to construct uniform MOF shell‐derived carbon confined SnO 2 /Co nanocubes (SnO 2 /Co@C) . The fabrication process is shown in Figure f.…”

“…Copyright 2016, American Chemical Society. e–g) Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

Hollow Metal–Organic‐Framework Micro/Nanostructures and their Derivatives: Emerging Multifunctional Materials

“…MOF‐derived hollow structures consisting of or doped with metal oxides (SnO 2 , Mn 2 O 3 , Fe 2 O 3 , Co 3 O 4 , CuO, ZnO, and so on) and metal sulfides (Co 9 S 8 , ZnS, and so on) have been extensively used as anode electrode materials in LIBs with large capacity, high power, and long cycle stability. It is believed that hollow porous electrode materials containing well‐connected carbon matrices and metal‐based compounds may not only support abundant active sites and fast ion transport, but also help buffer the volume expansion caused by Li + intercalation.…”

Rational Microstructure Design on Metal–Organic Framework Composites for Better Electrochemical Performances: Design Principle, Synthetic Strategy, and Promotion Mechanism

“…The MOFs@CoSnO 3 composite was then transformed into C@SnO 2 ‐Co, displaying a reversible capacity of 400 mAh g −1 after 1800 cycles at 5 A g −1 as anode materials for lithium‐ion battery. Further studies showed that the Co nanoparticles not only ensured fast electron conduction, but also prevented the migration and agglomeration of the Sn species during repeated cycling processes . Interestingly, by using Co 3 O 4 nanocages as the growing seeds, hollow nanotube‐like Fe III ‐MOF‐5 nucleated from the surface of Co 3 O 4 to one direction outward by simply adding Fe(acac) 3 , Zn(NO 3 ) 2 , and H 2 BDC in a Co 3 O 4 ‐containing DMF–ethanol mixed solution and the subsequent hydrothermal reaction, finally obtaining starfish‐shaped Co 3 O 4 /Fe III ‐MOF‐5 composite.…”