Electrochemical construction and sodium storage performance of three-dimensional porous self-supported MoS_2 electrodes

摘要

Three-dimensional (3D) porous self-supported MoS2 electrodes are constructed by electrodepositing coupled with high-temperature heat treatment using 3D porous Cu prepared via electroless plating as the substrate, and directly used as anode of sodium-ion battery. The 3D porous structure can accommodate the volumetric expansion/shrinkage and alleviate the stress caused from the large volumetric changes of MoS2 electrodes during electrochemical cycling. Meanwhile, large surface area of this unique configuration enables sufficient electrode/electrolyte interaction and fast electron transportation. Besides, the influence of heat treatment temperatures on the sodium storage performance of MoS2 electrode is also investigated. The electrochemical test result shows that the 3D porous self-supported MoS2 electrode heat treated at 350 degrees C has the best electrochemical performance. It demonstrates a high first reversible capacity of 714.1 mAh g(-1) at 50 mA g(-1) with a high first Coulombic efficiency of 84%, and a good capacity retention of 306.8 mAh g(-1) after 100 cycles at 2 A g(-1). The reversible capacity at 3.2 A g(-1) shows high value of 241 mAh g(-1), which is 37% of that at 0.05 A g(-1).