Abstract
Sn-based compounds with buffer matrixes possessing high theoretical capacity, low working voltage, and alleviation of the volume expansion of Sn are ideal materials for lithium storage. However, it is challenging to confine well-dispersed Sn within a lithium active matrix because low-melting-point Sn tends to agglomerate. Here, we apply a metal-organic framework (MOF) chemistry between Sn-nodes and lithium active ligands to create two Sn-based MOFs comprising Sn2(dobdc) and Sn2(dobpdc) with extended ligands from H4dobdc (2,5-dioxido-1,4-benzenedicarboxylate acid) to H4dobpdc (4,4’-dioxidobiphenyl-3,3’-dicarboxylate acid) with molecule-level homodispersion of Sn in organic matrixes for lithium storage. The enhanced utilization of active sites and reaction kinetics are achieved by the isoreticular expansion of the organic linkers. The reversible formation of coordination bonds during lithium storage processes is revealed by X-ray absorption fine structure characterization, providing an in-depth understanding of the lithium storage mechanism in coordination compounds.
Highlights
Sn-based compounds with buffer matrixes possessing high theoretical capacity, low working voltage, and alleviation of the volume expansion of Sn are ideal materials for lithium storage
Combined studies with in situ powder X-ray diffraction (PXRD), X-ray absorption fine structure (XAFS), high-resolution transmission electron microscopy (TEM) (HRTEM) characterization, ex situ Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectroscopy and theoretical modeling provided a detailed analysis of the lithium storage mechanism in these Snbased metal-organic framework (MOF), highlighting that the reversible formation of coordination bonds is the core and foundation to solve particle agglomeration and achieve satisfactory active site utilization in coordination compounds
In comparison with the lithium storage properties and synthetic methods of reported Sn-based nanomaterials and other typical anode materials (Supplementary Table 7), these two welldesigned Sn-based MOFs with uniformly confined Sn centers and organic ligands synthesized through a simple solution method achieve a high reversible capacity and long-term cycling stability, verifying the effectiveness of the coordination chemistry strategy for lithium storage
Summary
Sn-based compounds with buffer matrixes possessing high theoretical capacity, low working voltage, and alleviation of the volume expansion of Sn are ideal materials for lithium storage. The extension of the ligand resulted in enhanced utilization of active sites and favorable reaction kinetics for Sn2(dobpdc) with an isoreticularly extended framework structure, presenting a high reversible capacity of 1018 mAh g–1 over 200 cycles and excellent rate capability, which outperforms other coordination compounds (Supplementary Table 1). Combined studies with in situ powder X-ray diffraction (PXRD), X-ray absorption fine structure (XAFS), high-resolution TEM (HRTEM) characterization, ex situ FTIR and XPS spectroscopy and theoretical modeling provided a detailed analysis of the lithium storage mechanism in these Snbased MOFs, highlighting that the reversible formation of coordination bonds is the core and foundation to solve particle agglomeration and achieve satisfactory active site utilization in coordination compounds
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
