Fabrication and electrochemical performance of unprecedented POM-based metal–carbene frameworks

Abstract

Unprecedented polyoxometalate based metal–carbene frameworks (POM-based MCFs) [Cu₁₀(H₃trz)₄(Htrz)₄](HPW₁₂O₄₀) (1) and [Cu₁₀(H₃trz)₄(Htrz)₄](H₂SiW₁₂O₄₀) (2) have been fabricated via a hydrothermal reaction between 1,2,4-triazole and Cu(CH₃COO)₂ with the saturated Keggin polyoxoanion [PW₁₂O₄₀]³⁻/[SiW₁₂O₄₀]⁴⁻ as a template for the first time. Single crystal X-ray diffraction analysis reveals the successful encapsulation of Keggin POMs into the three-dimensional POM-based MCFs with lvt-a topology based on their effective coordination with Cu ions. Interestingly, these novel 3D POM-based MCFs exhibit good electrochemical performance in lithium-ion batteries (LIBs) as anode materials, with first discharge capacities of ca. 1620 and 1245 mA h g⁻¹ for 1 and 2, respectively, at a current density of 100 mA g⁻¹, and stabilized discharge capacities of ca. 570 mA h g⁻¹ for 1 and 426 mA h g⁻¹ for 2 after 100 cycles. This, in combination with their high thermal stability, suggests their good LIB application potential.