Mesoporous Iron Family Element (Fe, Co, Ni) Molybdenum Disulfide/Carbon Nanohybrids for High-Performance Supercapacitors

Abstract

As the demand for fuel continues to increase, the development of energy devices with excellent performance is crucial. Supercapacitors (SCs) are attracting attention for their advantages of high specific energy and a long cycle life. At present, the development of high-performance electrode materials is the main point for research and development of SCs. Transition metal sulfides have the advantages of a large interlayer space and high theoretical capacity, making them promising electrode materials. Herein, we reported a series of ultrathin mesoporous iron family element (Fe, Co, Ni) molybdenum disulfide (M_xMo_1-xS₂/C, M = Fe, Co, and Ni) by a template method. The original monolayer mesoporous structure of MoS₂/C was maintained, and accumulation and agglomeration of MoS₂/C were avoided. Based on our investigations, the best performance was that of Co_xMo_1-xS₂/C nanohybrids. Furthermore, the concentrations of Co and Mo ions were modulated to obtain the best performance, in which Mo and Co ions were released at 1:1, 1:2, and 1:3 ratios and they were named Co_xMo_1-xS₂/C-1, Co_xMo_1-xS₂/C-2, and Co_xMo_1-xS₂/C-3, respectively. Overall, these materials represent a significant improvement and show promise as high-performance SC electrode materials due to their enhanced capacitance and stability. At a current density of 0.5 A g^-1, Co_xMo_1-xS₂/C-2 has the optimal specific capacitance of 184 F g^-1. Co_xMo_1-xS₂/C-2 as an SC electrode exhibited better reversible capacity and cycling stability than MoS₂/C, which is an improvement over MoS₂/C regarding reversible capacity and cycling stability.