Porous carbon with large surface area derived from a metal–organic framework as a lithium-ion battery anode material

Abstract

A new Cd-based metal–organic framework (Cd-MOF), namely [Cd₃(TCPB)₂(H₂O)₂(DMF)₂]·7H₂O, has been constructed from Cd(NO₃)₂ and 1,3,5-tri(4-carboxyphenoxy)benzene (H₃TCPB) under solvothermal conditions. Single crystal X-ray diffraction analyses reveal that Cd-MOF displays a two-dimensional (3,6)-connected kgd net topology based on linear trinuclear Cd₃(COO)₆ secondary building units (SBUs) and exhibits one-dimensional opening channels. When treated as a precursor by calcining this Cd-MOF at 800 °C for 2 h, a porous carbon material was prepared. As an anode material for lithium-ion batteries (LIBs), the resulting porous carbon material exhibited an initial discharge of 2486 mA h g⁻¹ and a charge of 1683 mA h g⁻¹ at a current density of 300 mA g⁻¹ with a high initial coulomb efficiency of 98%. After 300 cycles, a high reversible capacity as high as 1285 mA h g⁻¹ could be still maintained, along with good rate capability and superior cyclic stability. The good electrochemical performance can be attributed to the unique pore structure and large surface area, which can largely offer more active sites for Li storage and cause an increase in the ability for the accumulation of charges.