Development of Design Model of Electric Double-Layer Capacitors as All-Purpose Energy Recovery Devices for Reducing COィイD22ィエD2 Emission

电双层电容器（EDLC）有望成为一种减少二氧化碳排放的通用能量回收装置。为了合理、可靠地使用带有活性炭电极的EDLC，必须建立一个描述EDLC平衡和动力学特性的模型。本研究项目对EDLC的充放电行为进行了研究，得到了以下结果：表征：采用氮气吸附法测定不同活化程度的高表面积活性炭的孔径、微孔体积、微孔表面积。孔径范围为0.6 ~ 1.0 nm，与水溶液中水合离子的孔径大小比较。平衡：通过监测p。p后的电流，成功地测量了具有不同孔隙特征和不同表面特征的活性炭组成的EDLC的静态容量，而不是恒流电荷测量的表观容量。所采用的碳被发现具有明显比那些具有相似表面积的活性炭纤维更大的容量。这种特性被认为来自于所使用的碱活性炭的内表面的随机性。动力学：利用构建的在线实验系统，成功地测量了EDLC充放电的瞬态过程。我们成功地建立了充电/放电行为的模型。该模型采用能斯特-普朗克方程来描述阴离子和阳离子，并考虑了碳电极的电阻。通过分析得到的时间常数表明，水合离子尺寸附近孔径的微小差异会极大地改变离子的迁移率，这可能是由于离子运动中的空间干扰。此外，还可以预测各种电阻对电容器充放电能力总体性能的影响。通过以上研究，成功建立了基于平衡和动力学特性的EDLC性能预测模型，并为活性炭EDLC的设计提供了实用的工具。少

Electric double-layer capacitor (EDLC) is expected to stand as an all-purpose energy recovery device for reducing carbon dioxide emissions. For reasonable and reliable use of the EDLC with activated carbon electrodes, a model for describing both equilibrium and kinetic characteristics of the EDLC must be established. This research project pursued charging/discharging behavior of EDLC and obtained the following results.1.Characterization : Employing nitrogen adsorption, we determined pore-sizes, micropore volumes, micropore surface area of high-surface-area activated carbons with different degree of activation. Pore sizes ranged form 0.6-1.0 nm, which compare with the sizes of hydrated ions in aqueous solution.2.Equilibrium : Static capacities -- not the apparent ones by constant current charge measurement -- of EDLC's composed of activated carbons with various pore characteristics and with various surface characteristics were measured successfully by monitoring electric current after p … More otential disturbance. The carbons employed were found to have significantly larger capacities than those of activated carbon fibers with similar surface areas. This characteristics are thought to come from the random nature of the interior surface of the alkali-activated carbons used.3.Kinetics : Transient processes of charging/discharging EDLC was successfully measured with on-line based experimental system constructed in this study. We succeeded in modeling the charging/discharging behavior. The model employed the Nernst-Planck equation for describing anions and cations, and included electric resistance of the carbon electrodes. The time constants obtained through the analysis showed that a small difference in pore diameter near the size of hydrated ions drastically changes the mobility of the ions probably because of steric disturbance in the movement of ions. Further, it was made possible to predict the effect of various resistances onto the total performance of the charge/discharge ability of capacitors.Through all the above study, a model for predicting performance of EDLC based both on equilibrium and kinetic characteristics has been successfully established, and showed usefulness as a design tool for activated carbon EDLC. Less