The Fabrication Of Rayon Mesoporous Activated Carbon Fiber

Supercapacitor （SC） as a new generation energy-stored apparatus started at the end of 1970s. Compared with the conventional capacitor, supercapacitor has the higher energy density, while its rate power density is larger than cell’s. Because of its no pollution discharge, supercapacitor is the best candidate to solve the energy crisis and also benefits to the green environment. However, the development of supercapacitor encounters a big challenge due to the material of electrode. How to improve the energy density of supercapacitor and reduce the cost of electrode is the central aim for researchers to conquer.The materials of electrode now are mainly focused on activated carbon, carbon gas jell, metal oxide, carbon nanotube and so on. Whereas, those materials are inefficiency for the large scale application on industrialization, due to the disadvantages of electricity properties, produce procedure, environment pollution and cost.Activated carbon fiber （ACF）, soft, small resistance and fiber form, which lies in the dominant advantage in the absorption area, is very suitable for the electrode of supercapacitor. However, with low strength, small mesopore rate and other disadvantages, ACF is not favorable for the researchers. Basing on the learning from literature, detail analysis of requirements for the SC electrode and the many years theory and practice accumulation of our group in the investigation of rayon thread with high strength and rayon carbon fiber with high purity and high strength, in the thesis we firstly fabricated the high strength rayon carbon fiber with pore-expanded elements, using rayon carbon proto-thread produced in domestic as the raw material. Following the formation theory of mesoporous activated carbon, we have expanded micro-porous of rayon carbon fiber into meso-structure which is required by SC electrode, in other words, we have produced the rayon mesoporous activated carbon fiber （RMACF） with certain strength and mesopore rate which meets the requirements of SC electrode.Considering the dense texture carbon fiber and the low strength activated carbon fiber, we have utilized the rayon carbon fiber （RCF） to produce mesopore in the fabrication technology. The formation of mesopore is more favorable due to RCF’s large pore gap structure which is helpful for the pore-expanded elements incoming. For the choose of the pore-expanded materials, we have used metal salt Ni（CH₃COO）₂ and FeCl₃ which have not been used as adding element for mesopore before, basing on the fabrication technology of meso-activate carbonBy deep investigation of the formation mechanism of mesopore which influenced by technology procedure and structure properties of fiber such as strength, special surface area and the distribution of pore, we have fabricated ACF, using domestic rayon carbon proto-thread. ACF fits the fundamental requirements of every department in 863 program, and its strength and mesoporous rate properties are confirmed by them.The new aspects of the thesis are following: firstly, we have used rayon carbon fiber for the first time as the raw material, and fabricated high strength rayon carbon fiber with the pore-expanded elements by exploring a new technology procedure to produce high strength. Secondly, after we had a better learning of properties of the pore-expanded elements and its effect on technology procedure and fiber structure properties, we have arrived RMACF having both certain strength and mesoporous rate from the high strength carbon fiber mentioned above. Then the mechanism of formation of mesopore is demonstrated fundamentally.