Capacitive mixing (CapMix) is an emerging technique that uses supercapacitors for harvesting salinity gradient energy. Here, positively charged quaternized poly(4-vinylpyridine) coated activated carbon and negatively charged nitric acid oxidized activated carbon are employed as electrodes for asymmetric CapMix (Asy-CapMix), enabling the production of electricity via four-step or two-step energy generation cycles without using an external power source and selective membranes. The voltage rise of this capacitor is 150.0 mV, and the average power density can reach as high as 65.0 mW m⁻². Both values are higher than those of CapMix using symmetric electrodes and an external power source or selective membranes and better than those of previous Asy-CapMix, including those with external power supplies. Such superior performance can be attributed to the high surface charge density and the good conductivity of the chemically modified activated carbon electrodes, which may give insight into the design of electrodes for high performance Asy-CapMix.

中文翻译：

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高性能非对称电容混合，带相反电荷的碳电极，可利用盐度差产生能量

电容混合（CapMix）是一种新兴技术，使用超级电容器来收集盐度梯度能量。在这里，带正电荷的季铵化聚（4-乙烯基吡啶）包覆的活性炭和带负电荷的硝酸氧化的活性炭被用作不对称CapMix（Asy-CapMix）的电极，从而可以通过四步或两步发电来发电无需使用外部电源和选择性膜即可循环运行。该电容器的电压上升为150.0 mV，平均功率密度可高达65.0 mW m ^-2。这两个值均高于使用对称电极和外部电源或选择性膜的CapMix的值，并且优于包括外部电源在内的以前的Asy-CapMix的值。如此优异的性能可以归因于化学修饰的活性炭电极的高表面电荷密度和良好的电导率，这可以深入了解高性能Asy-CapMix电极的设计。