Abstract

Capacitive deionization (CDI) shows promising potential for water desalination due to its high performance, energy efficiency, and environmental friendliness. Because of their excellent conductivity, chemical stability, and high surface area, carbon derivatives are the most used capacitive deionization electrode materials. Among these carbon materials, graphene is quite attractive because of its exceptional electrical conductivity and very large surface area compared with other carbon materials. In addition to the low energy requirements of the CDI that in many scenarios outperforms reverse osmosis, further reduction in the energy can be realized through recovering some of the input energy. The recovered energy can be used to power additional CDI cells, stored in other energy storage devices such as supercapacitors, or used in any other application. This study summarizes recent progress in implementing graphene as an electrode material for CDI and the different methods used for recovering energy from CDI cells. Furthermore, the energy consumption in CDI with and without energy recovery is compared with the most common desalination technologies such as reverse osmosis, multiple-effect distillation, and multistage flash distillation.

摘要

电容去离子 (CDI) 因其高性能、能源效率和环境友好性而在海水淡化方面显示出广阔的潜力。由于其优异的导电性、化学稳定性和高表面积，碳衍生物是最常用的电容去离子电极材料。在这些碳材料中，与其他碳材料相比，石墨烯具有出色的导电性和非常大的表面积，因此颇具吸引力。除了在许多情况下优于反渗透的 CDI 的低能量要求外，还可以通过回收部分输入能量来进一步降低能量。回收的能量可用于为额外的 CDI 电池供电，这些电池存储在其他储能设备中，如超级电容器、或用于任何其他应用程序。本研究总结了石墨烯作为 CDI 电极材料的最新进展，以及用于从 CDI 电池中回收能量的不同方法。此外，将有和没有能量回收的 CDI 的能耗与最常见的脱盐技术（如反渗透、多效蒸馏和多级闪蒸）进行了比较。