We will discuss the synthesis method of Ni (OH) 2-based materials, especially the new progress made in compounding with carbonaceous materials to improve the cycle stability and rate performance of Ni (OH) 2-based materials, including the synthesis of materials, special shapes Control of appearance and design of composite materials.
Supercapacitors have the advantages of large power density, long life and low production cost, and are considered to be one of the most promising energy storage systems. However, the low energy density of supercapacitors hinders its practical application. Since the stored energy is proportional to CV2, the energy density of the supercapacitor can be increased by increasing the capacitance "C" of the material or the operating voltage window "V" or both. However, organic electrolyte ions with a wide potential window tend to have poor conductivity, high cost, and easily cause environmental problems. Therefore, in order to improve energy density, electrode materials with high specific capacitance should be used. Therefore, designing suitable electrode materials with high specific capacitance has become a research hotspot. As the electrode material of supercapacitor, Ni (OH) 2 has the advantages of large theoretical capacity, low cost, natural abundance, and easy synthesis. It has attracted much attention in recent years. However, due to the low conductivity and small specific surface area of Ni (OH) 2, its capacity is seriously degraded. As an electrode material for electric double-layer supercapacitors, carbonaceous materials have an energy storage mechanism that depends on the adsorption and dissociation of electrolyte ions on the electrode surface. They have the advantages of good conductivity, abundant raw materials, low cost, and high electrochemical stability. Therefore, it is necessary to introduce highly conductive carbonaceous materials into Ni (OH) 2 to form composite materials to improve the capacitance performance. The author summarizes the synthesis methods of Ni (OH) 2-based materials, especially the new research progress in compounding with carbonaceous materials to improve the cycling stability and rate performance of Ni (OH) 2-based materials.
Composite materials based on Ni (OH) 2 all show the advantages of high specific capacity and good cycle performance, and all these materials include the use of carbonaceous materials. This shows that the low cost and environmental friendliness make the Ni (OH) 2 / carbon composite electrode gain broad application prospects in the field of energy storage. In addition, the latest developments in the synthesis methods and structures of electrode materials composed of Ni (OH) 2 and different carbon materials are reviewed, including the synthesis of original Ni (OH) 2 materials.
Based on the swelling effect and the principle of dissolution equilibrium, the research group of the author creatively uses CS2 / NMP mixed solvent to adopt extraction back extraction method to divide coal into heavy group, sparse middle group, dense middle group and light group at room temperature , And develop its utilization value according to the characteristics of each component, greatly improving the utilization efficiency of coal. Activated carbon obtained by acid treatment and alkali activation of the heavy groups not only has a large specific surface area, but also can effectively increase specific capacitance and improve rate performance. If this kind of activated carbon is combined with Ni (OH) 2, electrode materials of supercapacitors with better performance can be expected.
Generally, Ni (OH) 2-based supercapacitor equipment may play a key role in renewable energy, and is expected to solve environmental pollution problems and reduce the use of hydrocarbon fuels. With the rapid development of Ni (OH) 2-based electrode materials, high-performance supercapacitors with safe operation and environmental friendliness are suitable for practical energy storage devices. Therefore, the excellent electrochemical performance and reasonable structural design of Ni (OH) 2 composite materials have practical application potential in energy storage.