Synthesis Of Transition Metal Sulfide Electrode Materials And Research On The Performance Of Supercapacitors

In recent years,environmental problems caused by the large use of non-renewable resources such as fossil fuels have become increasingly serious,so the search for green and renewable energy sources is imminent.The storage of new energy has always been a topic of widespread concern among scientists.Supercapacitors are gradually appearing in people’s field of vision,and supercapacitors have higher power density and better cycle stability than batteries in the traditional sense.The electrode material is one of the main reasons for determining the performance of supercapacitors,among which transition metal sulfides have gradually attracted the attention of scholars due to their low price and large conductivity,and transition metal sulfides can also effectively improve the electrochemical performance of other types of electrode materials.However,most transition metal sulfide synthesis methods are complex,which is not conducive to their widespread promotion as electrode materials.In this paper,Co Mo O₄/Mo O₃@Cu Co Ni-S and Ni₃S₂/Co₉S₈/Ni S electrode materials were successfully synthesized by simple hydrothermal and electrodeposition methods,as follows:（1）Co Mo O₄/Mo O₃@Cu Co Ni-S nanomaterials were synthesized by hydrothermal method and electrodeposition method,and the electrochemical properties of Co Mo O₄/Mo O₃ before and after the recombination of Cu Co Ni-S were compared.Due to the core-shell structure formed after compounding with Cu Co Ni-S,the specific capacitance of Co Mo O₄/Mo O₃@Cu Co Ni-S is as high as 2600.0 F g^-1 at a current density of 1 A g^-1.With Co Mo O₄/Mo O₃@Cu Co Ni-S as the positive electrode,activated carbon as the negative electrode,and KOH/PVA as the solid electrolyte,an asymmetric supercapacitor was assembled.When the power density of the device is800.2 W kg^-1,the Co Mo O₄/Mo O₃@Cu Co Ni-S//AC device displays an energy density of up to 42.1 Wh kg^-1 and successfully lights up the LED bulb.The results show that the electrode material has broad application prospects.（2）Ni₃S₂/Co₉S₈/Ni S nanomaterials were synthesized by one-step electrodeposition method,and the effects of different deposition circles on their electrochemical performance were analyzed.The specific capacitance of the Ni₃S₂/Co₉S₈/Ni S-7electrodes obtained by optimizing the number of deposition turns is as high as 2785.3 F g^-1 at a current density of 1 A g^-1,and the capacitance retention rate is 84.8%after 3000cycles of constant current charge-discharge cycle.In addition,an asymmetric supercapacitor was assembled with Ni₃S₂/Co₉S₈/Ni S-7 as the positive electrode,activated carbon as the negative electrode,and KOH/PVA as the solid electrolyte.The unit provides an energy density of 40.1 Wh kg^-1 at a power density of 799.3 W kg^-1 and successfully lights up the LED bulbs.The results show that Ni₃S₂/Co₉S₈/Ni S-7 have broad prospects in the application of supercapacitor electrode materials.