| With the rapid development of energy storage devices,supercapacitors have attracted more and more attention and research.Supercapacitors are characterized by fast charge and discharge,stable safety performance,high energy density and power density.In order to develop high-performance supercapacitor devices,researching and developing the electrode materials with unique morphology and excellent electrochemical performance have become the key issues for supercapacitors.Nickel-based materials are widely used as transition metal compounds in supercapacitor electrode materials,and have high specific capacitance,stable performance,and various features of the morphology.Based on the morphology,structure and function,this paper designs and successfully prepares a variety of composite electrode materials based on nickel-based materials.By studying its structure,morphology,electrochemical properties and other aspects,the unique advantages of its materials are described.The main research content can be summarized as the following aspects:NiO/nitrogen-doped reduced graphene oxide composites were synthesized by a high-temperature and high-pressure reaction vessel.The preparation process is simple and efficient,and the process of reducing calcined graphene nanosheets by calcined in high temperature is avoided.At the same time,in the hydrothermal process,adding ammonia can not only dope non-metallic nitrogen elements that can lead toimproving the conductivity of graphene,but also can have a certain cutting effect on the graphene nanosheets under the alkaline conditions that can improve the specific surface area of the r-GO material.The composite materials have a discharge specific capacitance of 233 F·g-1 at a constant current of 1A·g-1.After 8,000 cycles life tests,the capacity retention rate can reach 86%,and can realize long-time operation.The nanoflower-like NiB-Co-P-O electrode material was synthesized by hydrothermal method,and the mass ratio of doped Co was changed.The use of Ni,Co metal in the redox reaction synergy can improve the electrochemical performance.When the mass ratio of Ni:Co is 8:1,the prepared Nis-Co-PO has the best electrochemical performance.Under the galvanostatic current density of 1A·g-1,the material has a tantalum-capacitance ratio.The capacitance reaches 956 F·g-1.At the same time,in order to prove the commercial value of synthetic materials,it is assembled into a hybrid supercapacitor with a window voltage of up to 1.8 V.At a constant current density of 1 A·g-1,the specific capacitance of the device reaches 106 F·g-1.The nano-tubular material FeCo2O4 was deposited on the Ni foam by a chemical deposition method,and the nano-sheet CoNi2S4 was loaded on the FeCo2O4 tube wall by electrochemical cyclic voltammetry.By controlling the plating reaction time,we strive to achieve the best performance,study the morphology and the structure of the composite material,and test the electrochemical properties of the electrode material.The SEM images clearly shows the differences due to the plating time.The TEM image shows that the nanosheets are loaded on the tube wall of the tubular material and the inside diameter and the length of the tube.Under the three-electrode system,the composite material under the condition of 10 cycles of electroplating was measured.The test results showed that the specific capacitance of the synthetic electrode material reached 11.607 F·cm-2 at a constant current density of 5 mA·cm-2. |
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