Method for removing salt by using three-dimensional carbon electrode

Abstract

The invention relates to a method for removing salt by using a three-dimensional carbon electrode, belonging to the field of sea water desalination. According to the method, natural wood is used as acarbon precursor, a three-dimensional carbon skeleton is prepared by using a process of firstly carrying out pre-carbonization and then activating, and the prepared three-dimensional carbon skeleton is prepared into a capacitor so as to be used for removing salt. The carbon skeleton has a large number of vertically aligned, parallel and low-bending macroporous channels, thus facilitating the direct transmission and diffusion of electrolyte ions. After activation is finished, a plurality of micropores are simultaneously formed inside the carbon skeleton, the micropores are distributed on the inner walls of ordered through holes, and the large number of micropores provide a place for salt ion electrosorption. Therefore, the carbon electrode of the structure significantly enhances the diffusion of the salt solution in the electrode, shortens the time and distance of the ions reaching the micropores, and finally improves the performance of desalting.

Description

technical field [0001] The invention relates to a method for desalting by using a three-dimensional carbon electrode, which belongs to the field of seawater desalination. Background technique [0002] Capacitive Deionization (CDI) is an emerging technology for seawater desalination. Compared with current commercial seawater desalination technologies (such as membrane reverse osmosis technology and multi-stage flash desalination technology), CDI technology has the advantages of high efficiency, low energy consumption, and easy miniaturization. The traditional CDI electrode preparation process usually consists of active material (usually activated carbon), binder (PTFE or PVDF) and conductive agent (usually carbon black) through mixing and stirring, and then scrape coating onto the current collector ( Usually on carbon paper), it is made after hot pressing and drying. However, this process will face the following difficulties in practical application: when the electrode is t...

AI Technical Summary

Problems solved by technology

However, the carbon electrodes with high loading capacity, especially activated carbon, have chaotic pores, which often affect the desalination performance due to slow mass transfer and diffusion.

For this kind of ultra-thick carbon electrode, it often takes a long time for the electrolyte to diffuse into the electrode, and it may not even be completely saturated. While the desalination capacity decreases, the desalination efficiency is also greatly reduced.

Therefore, it is also a great challenge to prepare a three-dimensional carbon electrode with high loading capacity and excellent electrical desalination performance (salt removal amount, desalination rate).

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