Cobalt-Based MOFs as an Efficient Sulfur Host for High-Performance Lithium-Sulfur Batteries

Herein, the previously reported Co-(3-AIN)-bio-MOF, which possesses a rigid one-dimensional channel structure, was selected as sulfur host to construct a cathode for lithium-sulfur batteries. The as-synthesized MOFs and the resulting MOF@S composite were thoroughly characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), and Fourier-transform infrared spectroscopy (FTIR). Electrochemical performance evaluations demonstrated an initial discharge specific capacity of 851.61 mAh g–1 at 0.1 C, with a retained capacity of 555.63 mAh g–1 even at higher current rates. When the current rate was switched back to 0.1 C, a reversible capacity of 894.04 mAh g–1 was achieved, which corresponds to a 100 % recovery of the initial capacity. The results indicate that the cobalt-based MOF endows the sulfur cathode with high specific capacity, excellent cycling stability, and outstanding reversibility, demonstrating its promise for use as a cathode material for Li-S batteries. This work presents a novel strategy to tackle the critical challenges of poor solid-liquid interface contact and the polysulfide shuttle effects in sulfur-based cathodes.