Preparation And Properties Of Supercapacitor Electrode Materials

As a new kind of energy storage device, supercapacitors have aroused huge attentions of the researchers worldwide due to its high power density, rapid charge-discharge energy storage, long cycle life, wide temperature range, easy to maintenance and friendly to the environment. Among them, the electrode material is one of the key factors to the supercapacitors' electrochemical performance, but most of the current electrode materials exhibt some natural shortcomings, such as poor electrical conductivity, low specific capacity and unstable structure, which lead to the low energy density, short life cycle and poor rate capability. With the intense research of supercapacitors, the preparation of electrode materials with excellent performance and low cost gradually becomes the focus of attention. Based on these considerations, we start from the structure building of materials and select different raw materials using varieties of methods to prepare electrode materials with some special composition and microstructure, therefore, they possess excellent electrochemical performance. The specific methods are shown as follows:(1) Nitrogen-doped porous carbon materials based on silk cocoon for supercapacitors: We choose silk cocoon as the carbon resource, because it is rich in nitrogen content. Using a two-step synthesis method consist of carbonization and activation, we obtained nitrogen-doped porous carbon material with high specific surface area(3841 m2/g). Through charge-discharge test, it exhibits a specific capacitance up to 408 F/g.(2) Amorphous Ni-Co binary oxide for supercapacitors: We prepared precursor via chemical bath deposition by using nickel acetate and cobalt acetate as raw materials, then the final product was synthesized through the low temperature calcination. This material shows a high specific capacitance of 1608 F/g at a current density of 0.5 A/g.(3) Hybrid Ni-Co oxide @ 3D carbon skeleton derived from pollen grains for supercapacitors: Using the carbonized pollen grain as the carbon skeleton, then the precursor was deposited on the surface of pollen grain and final product was synthesized via calcinations, eventually. This special composite exhibits high specific capacitance(1625 F/g) and excellent cycle stability.