Study On Electrode Materials Of Conductive Polymer And Technology Of Solid Electrolyte Capacitor

As a novel kind of energy storage component, organic solid electrolyte capacitor (OSEC) has lots of merits such as with high energy density, high power density, long life time and broad temperature range for practical application et al. OSECs have already been applied in fields such as computer, radar, missile, supersonic airplane, automatic control system. Due to the wide application field and huge commercial value, more and more attention is being paid on the research of OSECs. Currently, studies on OSECs are mainly focused on the preparation of high performance electrode materials and device. In this dissertation, we systematically studied on the preparation of high performance device involving in material, electrode, and capacitor, which includes the synthesis of high yield conductive polymer monomer, the preparation high conductive and stable polymer electrode thin films, the processing, fabrication , and mechanism of thin film for slice OSEC, the fabrication and property of high frequency low ESR OSEC, the disable mechanism and reliability of OSEC, and the feasibility of large scale production for OSEC. The main results are as following.1. Synthetic method and processing for novel monomer to synthesize conductive poly(3,4-ethylene dioxythiophene) (PEDT) polymer as a cathode material fro sliced solid capacitor was optimized. The results show that using this novel in situ chemical polymerization technique equivalent series-wound resistance decreased from 300 mΩto 40 mΩ. The frequency range increased from 10 KHZ to 100 KHZ. The capacitor and its fabrication method were patented via No. 03105908.2.2. During the synthesis of PEDT monomer, using porous copper as a de-carboxylic agent, reaction temperature reduces 50℃, and reaction time decreases 6 hr. On the other hand, final target yield increases from 25% using proton type solvent which is soluble for reactant but insoluble for product, and the product can be easily purified by separation funnel and distillation to attain high grade. Moreover, solvent can be recycled as well as environmental friendly. This result is applied patent through appl. No. 200610055264.X.3. As the reaction of PEDT polymerization involves in cationic free polymeric mechanism, which the reaction rate is very fast and uneasily controlled, in this work a novel method for using unique oxidant, solvent system, and polymerization improver was applied. As a result, the conductivity of polymer film can be modified from 10 to 100 S/cm, which was patented via No. ZL03105755.1.4. Using surfactant active processing and thin film absorption technique, the eduction yield of capacitance increased from 35% to 95% (Patent No. ZL03105907.4).5. Using in situ doping into in situ deposition PEDT electrode, the defect in metal oxide was remedied, and the conductivity of polymer film was greatly improved. At the same time, film processing procedure was simplified. This work was patented through No. 03105908.2.6. It is first time to deposit silane coupling agent on surfactant polished the core surface of OSEC and fabricate silane coupling agent-PEDT interfacial material as internal separator. It was found that as internal separation technique is significantly helpful to improve the pressure endurance capability of the OSECs, e.g., in the case of identical volume and exterior size, the working pressure of product using internal separation technique has been doubled.7. The variation rule of OSEC conductivity of polymer films deposited on flat and porous surface was found, and thin film formation mechanism and model in limited space was established, which paved base stone for polymer thin film deposition on porous surface.8. The working pressure of the obtained PEDT OSEC is 2-16 V, and the capacitance ranges from 10 to 20μF. The parameter of working pressure , capacitance, wasting, frequency and temperature characteristic is much better than those of MnO₂ capacitor, which is comparable to the device performance listed in USA KEMET Co. product catalogue. At the present stage, large scale production is being attempted in relevant enterprise using the result and technique achieved in this work.In summary, a novel series of capacitors based on PEDT conductive polymer were systematically studied, and high performance device was achieved. It can be anticipated that more novel kind of capacitors using other different organic electronic materials can be exploited with the pioneering study in this work.