Study On Preparation Of Transition Metal Sulfide/ Oxide Electrode Materials And Their Supercapacitor Performance

The development of supercapacitors with high performance,high energy density has been a research hotspot.Transition metal sulfides and oxides have multiple active sites,accelerating the rate of electron transfer and mass transfer and promoting electrolyte diffusion into the nanoelectrode.Based on the above analysis,the specific research content is as follows:1.One-step solvothermal method was used to synthesize the pine tower-like structure Ni-Co-Sx nanoarray.The optimized Ni-CO-S4 material has a higher specific capacitance(2215 F g-1 at 0.5 A g-1),and the capacitor retention rate is still 90.16%after 10,000 cycles.In addition,Ni-Co-S4 is used as an anode material in combination with cathode activated carbon to assemble a high-performance asymmetric supercapacitor(Ni-Co-S4//AC),with a high energy density of 36.6 W h kg-1,and two in series Ni-Co-S4//AC can light up the LED for up to 15 minutes.2.The Co-MOF material is deposited on the foamed nickel by the Solvothermal method and used as a precursor(Co-MOF/NF).Using electrochemical deposition method,Ni-Co alloy was electrodeposited on the surface of the precursor Co-MOF/NF to prepare a Ni-Co@Co-MOF/NF nano-electrode material without binder and conductive additives.The Ni-Co@Co-MOF/NF material completely and evenly covers the precursor,forming a three-dimensional cross porous structure similar to nano honeycomb.The Ni-Co@Co-MOF/NF electrode has a specific capacitance of up to 2697.5 F g-1 at a current density of 1 A g-1.Using Ni-Co@Co-MOF/NF as the anode material and activated carbon(AC)as the cathode material,assembled into an asymmetric supercapacitor Ni-Co@Co-MOF/NF//AC showed good cycle stability(10000 times 80.2%retained after cycling)and maximum energy density 61.4 W h kg-1(power density 853 W kg-1).3.Using Co-MOF as a template,CUCo2S4 nanomaterials were prepared on the electrode using the electro-chemical co-deposition method and changing the electrodeposition temperature.Studies have shown that when the electrodeposition temperature is 45?,high-performance electrode materials(CuCo2S4-45)can be prepared,whose micro-morphology has a unique porous three-dimensional three-dimensional ultra-thin honeycomb structure.The specific capacitance of CuCo2S4-45 material reaches 3079 F g-1 at 1A g-1.When the current density increases to 20 A g-1,the specific capacitance is 2512 F g-1.The asymmetric supercapacitor CuCo2S4-45//AC with activated carbon(AC)has excellent cycle stability(82.02%retention after 10,000 cycles),maximum energy density 63.6 W h kg-1(power density 700 W kg-1),This shows that the material has great practical application.