Cyclooctatetrathiophene Based MOF-Derived Porous Materials as High- Performance Anode for Lithium-Ion Batteries

Extensive research on anodes with higher capacity than carbon materials is driven by the demand for lithium-ion batteries with higher energy density. But cycling stability of high-capacity anodes is hindered by the structural collapse. Metal-organic frameworks (MOFs) are an emerging class of crystalline materials, and their derivatives are expected as alternative high-capacity anodes, resulting from the merits of easy functionalization and pore engineering. In this study, a novel porous Co-MOF-derived composite anode was prepared by the pyrolysis of nonporous Co-cyclooctatetrathiophene tetrapyridine (Co-COTTTP) template. The resulting porous carbon based composite anode demonstrated high specific capacity and long cycling stability in the assembled cells. Co-COTTTP-500 delivered a high reversible specific capacity of 1005.7 mAh g ⁻¹ after 100 cycles at 0.1 A g ⁻¹ and can be cycled steady for 800 cycles at 1 A g ⁻¹ , indicating the structure stability during cell operation. The comprehensive investigation of the framework structure and the composition of Co-COTTTP-derived composite anodes revealed that the exposed rich redox active sites, appropriate degree of graphitization, and heteroatom doping in the composites effectively enhanced the electrochemical performance of the composite anodes. In summary, this study provides a feasible strategy to prepare high-performance MOF-derived anodes, contributing to the fabrication of high-energy-density lithium-ion batteries.