Practical use of a large capacity electric double layer capacitor for altitude use of the energy

在这项工作中，首次用PEA方法测量了EDLC中正负电荷的时空行为。同时，将PEA法和能量转换法得到的电容进行了比较。结果表明，采用比表面积为2000m~2/g、平均孔径为2.72 nm的活性碳作为EDLC电极材料，其负电荷密度约为-173C/m2，正电荷密度约为70.7C/m2，正负电荷空间分布不均匀，电荷聚集区集中在炭质电极的中心部位。用PEA方法测得的正负电荷行为反映了EDLC中异质电荷的分布。此外，为了提高电容…，极化电极使用了凯金黑而不是常规使用的乙炔黑更多的是基于活性碳的EDLC。通常情况下，与乙炔黑相比，凯金黑具有更高的导电性，因此可以认为凯金黑是一种导电填料。通过放电特性对所制备的EDLC的电容进行了评价。结果表明，与乙炔黑相比，含有EDLC的凯金黑具有很高的比容量。其中，含有EDLC的8wt%的凯金黑的比容量最高。其中最好的乙炔黑的比电容为59.2F/g，从10wt%的乙炔黑和8wt%的凯金黑的电容随温度的变化来看，8wt%的乙酮黑的比容量在高温下表现出非常稳定的电容。此外，还对碳质材料进行了改性，以提高EDLC的电容和电荷密度。在150℃下，考察了10min~1h的最佳等离子体表面处理条件。等离子体源为氮气中的高频辉光放电。工作气体压力为13.3Pa.电极的设置使得EDLC样品被辉光放电覆盖。结果表明，碳素材料经等离子体表面处理后，空间电荷密度有所提高。此外，还对活性炭片进行了改性，以提高EDLC的容量和能量密度。血浆表面处理时间分别为1、5、10、20、30min。等离子体源为Ar气体中直流辉光放电。压力为20Pa，正负极间距为20 mm。直流功率为70W。用直流辉光放电将活性炭片覆盖在炭片上。作为等离子体表面处理的结果，由于活性炭片的BET比表面积随着Ar等离子体刻蚀而增大，因此具有活性炭片的EDLC单电池在更高的放电率下变得更加明显。此外，通过等离子体表面处理可以提高EDLC单电池的电容。在高倍率放电条件下，经过1min等离子体表面处理后的EDLC电池比采用原活性炭片的EDLC电池的容量提高了2%。较少

In this work, it is first measured the spatio-temporal behavior of positive and negative charges in EDLC using the PEA method. At the same time, the capacitance obtained by the PEA method was compared with those obtained by the energy conversion method. As the results, in the case of using activated carbon which has 2000 m^2/g of specific surface area and 2.72 ran of average pore diameter as the materials of electrode for EDLC, negative charge density was about -173 C/m^2 and positive charge density was about 70.7 C/m^2. The result also showed that the distributions of positive/negative charges were spatially uneven and that the charge accumulation region concentrated on central part of the carbonaceous electrode of EDLC. The behavior of negative and positive charges measured by the PEA method reflected the hetero-charges distribution in EDLC. Additionally, ketjen black was used for polarized electrodes instead of conventionally used acetylene black in order to improve the capacitance … More of activated carbon-based EDLC. Usually, ketjen black exhibits higher conductivity compared with acetylene black, so that ketjen black could be considered as conducting filler. The capacitance of prepared EDLC was evaluated through discharge characteristics. It was found that the ketjen black containing EDLC showed very high capacitance compared to acetylene black one. Especially, 8 wt% ketjen black containing EDLC showed the highest capacitance among the prepared samples. The specific capacitance of the best one was evaluated as 59.2F/g. It was also found that the 8 wt% ketjen black containing EDLC exhibited very stable capacitance at elevated temperature from temperature dependence of capacitance for 10 wt% acetylene black containing EDLC and 8 wt% ketjen black one. Furthermore, carbonaceous materials were modified in order to improve capacitance and charge density in EDLC. Optimal conditions for plasma surface treatment of activated carbon have been examined for times from 10 min to 1 h at 150℃. The plasma source was a high-frequency glow discharge in N2. The operating gas pressure was 13.3 Pa. The electrode was set up so that the EDLC sample was covered with the glow discharge. As the results, space charge density was improved by the plasma surface treatment of carbon materials. Moreover, an activated carbon sheet was modified, to improve capacitance and energy density of EDLC. The plasma surface treatments were carried out for 1, 5, 10, 20, and 30 min. The plasma source was a DC glow discharge in argon gas. The pressure was 20 Pa and the distance between positive and negative electrodes was 20 mm. DC power was 70W. The activated carbon sheets were set up to cover the sheets with the DC glow discharge. As the results of plasma surface treatment, EDLC single cells with the activated carbon sheets became more marked at higher discharge rate because the BET surface area of activated carbon sheet increased with argon plasma etching. In addition, capacitance of EDLC single cells can be improved by the plasma surface treatment. Capacitance of the EDLC cells with the activated carbon sheets after 1 min plasma surface treatment was increased 2% compares to EDLC cells with the original activated carbon sheet at a high discharge rate. Less