Mesoporous\nIron Family Element (Fe, Co, Ni) Molybdenum\nDisulfide/Carbon Nanohybrids for High-Performance Supercapacitors

Abstract

As the demand for fuel continues to increase, the development\nof\nenergy devices with excellent performance is crucial. Supercapacitors\n(SCs) are attracting attention for their advantages of high specific\nenergy and a long cycle life. At present, the development of high-performance\nelectrode materials is the main point for research and development\nof SCs. Transition metal sulfides have the advantages of a large interlayer\nspace and high theoretical capacity, making them promising electrode\nmaterials. Herein, we reported a series of ultrathin mesoporous iron\nfamily element (Fe, Co, Ni) molybdenum disulfide (M_<i>x</i>Mo_1–<i>x</i>S₂/C, M\n= Fe, Co, and Ni) by a template method. The original monolayer mesoporous\nstructure of MoS₂/C was maintained, and accumulation and\nagglomeration of MoS₂/C were avoided. Based on our investigations,\nthe best performance was that of Co_<i>x</i>Mo_1–<i>x</i>S₂/C nanohybrids. Furthermore,\nthe concentrations of Co and Mo ions were modulated to obtain the\nbest performance, in which Mo and Co ions were released at 1:1, 1:2,\nand 1:3 ratios and they were named Co_<i>x</i>Mo_1–<i>x</i>S₂/C-1, Co_<i>x</i>Mo_1–<i>x</i>S₂/C-2, and Co_<i>x</i>Mo_1–<i>x</i>S₂/C-3, respectively. Overall, these materials\nrepresent a significant improvement and show promise as high-performance\nSC electrode materials due to their enhanced capacitance and stability.\nAt a current density of 0.5 A g^–1, Co_<i>x</i>Mo_1–<i>x</i>S₂/C-2 has the optimal specific capacitance of 184 F g^–1. Co_<i>x</i>Mo_1–<i>x</i>S₂/C-2 as an SC electrode exhibited better reversible\ncapacity and cycling stability than MoS₂/C, which is an\nimprovement over MoS₂/C regarding reversible capacity and\ncycling stability.