Heightened Integration of POM-based Metal-Organic Frameworks with Functionalized Single-Walled Carbon Nanotubes for Superior Energy Storage.

Abstract

To increase the conductivity of polyoxometalate-based metal-organic frameworks (POMOFs) and promote their applications in the field of energy storage, herein, a simple approach was employed to improve their overall electrochemical performances by introducing a functionalized single-walled carbon nanotubes (SWNT-COOH). A new POMOF compound, [Cu18 (trz)12 Cl3 (H2 O)2 ][PW12 O40 ] (CuPW), was successfully synthesized, then the size-matched functionalized SWNT-COOH was introduced to fabricate CuPW/SWNT-COOH composite (PMNT-COOH) by employing a simple sonication-driven periodic functionalization strategy. When the PMNT-COOH nanocomposite was used as the anode material for Lithium-ion batteries (LIBs), PMNT-COOH(3) (CuPWNC:SWNT-COOH=3:1) showed superior behavior of energy storage, a high reversible capacity of 885 mA h g-1 up to a cycle life of 170 cycles. The electrochemical results indicate that the uniform packing of SWNT-COOH provided a favored contact between the electrolyte and the electrode, resulting in enhanced specific capacity during lithium insertion/extraction process. This fabrication of PMNT-COOH nanocomposite opens new avenues for the design and synthesis of new generation electrode materials for LIBs.