Cobalt Tungstate Nano Materials with Cockscomb Flower

Supercapacitors are energy storage devices between batteries and traditional capacitors. Because of its high charging and discharging efficiency, high power density, long cycle life and friendly environment, it is widely used in transportation, mobile communications, information technology, aviation, aerospace and national defense science and technology.

Cobalt tungstate is a very important functional material, which has a wide range of applications in photocatalysis, optical fibers, capacitors, electrocatalytic oxidation and other fields. There are many preparation methods of cobalt tungstate, such as coprecipitation, hydrothermal, solvothermal, microemulsion, etc. The morphology of cobalt tungstate is more, such as cobalt tungstate nanowires, nanorods, nanospheres, etc. In addition, there is a cobalt tungstate with cockscomb-like morphology. This cobalt tungstate nanomaterial with cockscomb-like morphology is more special in theory. Basic research and practical application are of great significance.

Cobalt tungstate nano-materials with cockscomb flower shape were prepared by solvothermal synthesis under the condition of no model agent by controlling the crystallization temperature and time. The preparation method is simple, the morphology is special and the cost is low. Cobalt tungstate nano-material with cockscomb flower shape as electrode material has good electrochemical performance in KOH electrolyte. The preparation process includes:

S1: Using cobalt salt as raw material, adding a certain amount of cobalt salt to ethylene glycol or solvent containing ethylene glycol, stirring fully until cobalt salt dissolves, the cobalt salt solution with concentration of 0.05-0.8 mol/L is prepared.

S2: Sodium tungstate with the same molar amount of cobalt salt was added into the cobalt salt solution of S1, and the mixed solution was formed by stirring evenly.

S3: The mixed solution of S2 was transferred into the reactor and crystallized at 140-220 ℃ for 6-18 H. The product was naturally cooled to room temperature, washed several times with distilled water and ethanol, and then dried at 55-65 ℃ for 10-12 h to obtain cobalt tungstate nano materials.

Cobalt tungstate nano-material with cockscomb flower shape as electrode material has good electrochemical performance in KOH electrolyte. It achieves excellent specific capacitance, loop life and rate performance in three-electrode system. Under 1Ag-1 condition, the specific capacitance reaches 1016Fg-1. After 5000 charging and discharging cycles, the capacitance retention rate of cobalt tungstate electrode is still 90%.

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