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

Abstract

Extensive research on anodes with higher capacity than carbon-based materials is driven by the great demand for lithium-ion batteries with higher energy density. However, the cycling stability of high-capacity anodes is usually hindered by significant volumetric changes and structural collapse during the cycling process. In this study, a novel porous Co-MOF-derived composite anode was prepared by the pyrolysis of nonporous Co-cyclooctatetrathiophene tetrapyridine (Co-COTTTP) template. X-ray absorption spectroscopy and high resolution transmission electron microscopy revealed that the precise composition of Co-COTTTP-derived composite anodes with exposed rich redox Co3O4 active sites, appropriate degree of graphitization, and N, S-doping, which effectively enhanced the electrochemical performance of the composite anodes. Thus, the resulting porous MOF-derived composite anode demonstrated high specific capacity and long cycling stability in the assembled batteries. Specifically, the cells assembled with Co-COTTTP-500 anodes 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. This study provides a feasible strategy to prepare high-performance MOF-derived anodes and deep understanding for the structure-activity relationship, contributing to the fabrication of high-energy-density lithium-ion batteries.

Keywords: metal-organic frameworks, MOF-derived anode, Co-cyclooctatetrathiophene tetrapyridine, N, S-doping, Lithium-ion batteries