Synthesis Of The NiMoS₄ Composite Electrode Materials And Their Supercapacitive Properties

Owing to many advantages including the high theoretical specific capacity and easy availability,NiMoS₄ can be used as the electrode material for supercapacitors.However,the specific capacity is still much lower than its theoretical value,which is mainly attributed to the poor conductivity and agglomeration.Focusing on the above problems,the capacitance performance of NiMoS₄-based composites is improved in this paper by complexing with lamellar materials and conductive polymers or establishing the self-supporting electrodes.The contents are as follows:（1）The NiMoS₄/reduced graphene oxide（NiMoS₄/RGO）nanocomposites are prepared by their electrostatic attraction through the one-step hydrothermal method.The prepared NiMoS₄/RGO nanocomposite exhibits the specific capacity of 124 m Ah/g at the current density of 1 A/g,much higher than that of pure NiMoS₄（67 m Ah/g@1 A/g）.This is mainly attributed to the fact that the RGO with the high specific area and conductivity cannot only improve the charge transfer ability,but also inhibit the agglomeration of NiMoS₄ and facilitate the ion diffusion process.The assembled NiMoS₄/RGO-1//AC asymmetric supercapacitor can exhibit the energy density of 65 Wh/kg at the power density of 1125W/kg,and specific capacity retention rate of 81%after 5000 charge/discharge cycles.（2）The graphene oxide/polyaniline（GO/PANI）was firstly prepared by in-situ polymerization of aniline on GO surface,and then the NiMoS₄ is loaded on GO/PANI by the hydrothermal method to obtain the NiMoS₄@RGO/PANI nanocomposite.The specific capacity of NiMoS₄@RGO/PANI nanocomposite is 204 m Ah/g at 0.25 A/g.In addition,the NiMoS₄@RGO/PANI-1//AC asymmetric supercapacitor possess the energy density of 31Wh/kg at a power density of 1500 W/kg.After 6000 charge/discharge cycles,the specific capacity of this asymmetric supercapacitor can still retain 93.13%of the initial capacity,indicating the excellent cycle stability.（3）In order to avoid the addition of adhesive that block the charge migration,the NiMoS₄@RGO/Ni foam self-supporting electrode is successfully prepared by the hydrothermal method,which can be directly used as the supercapacitor electrode.The NiMoS₄@RGO/Ni foam exhibits the specific capacity of 408 m Ah/g at 1 A/g.The corresponding NiMoS₄@RGO/Ni foam-1//AC asymmetric supercapacitor exhibits the good capacitance performances such as the energy density of 67.4 Wh/kg at power density of562.5 W/kg,and the specific capacity retention of 88%after 8000 charge/discharge cycles.