Concentration Flow Cells for Efficient Salinity Gradient Energy Recovery with Nanostructured Open Framework Hexacyanoferrate Electrodes

Document Type

Article

Publication Date

5-30-2018

Abstract

Salinity gradient (SG) energy is a large and renewable resource for clean energy production, which naturally exists between seawater and river water, and can also be created during desalination processes and at various industry sites. Recently, a new approach for efficient SG energy recovery was proposed based on concentration flow cells. However, it is not clear what the working principle of this new system is and how the electrode properties will affect the performance of this system. In this study, four different hexacyanoferrate electrodes (copper hexacyanoferrate, CuHCF; nickel hexacyanoferrate, NiHCF; manganese hexacyanoferrate, MnHCF; zinc hexacyanoferrate, ZnHCF) were explored in this system and the properties of these electrodes after discharging in synthetic seawater and freshwater were fully examined. Na+ intercalation/deintercalation processes on the hexacyanoferrate electrodes were confirmed by cyclic voltammetry, X-ray powder diffraction, and X-ray photoelectron spectroscopy, which significantly depend on the crystal structures and elemental compositions of the electrodes. NiHCF and CuHCF worked well, while MnHCF and ZnHCF showed much worse performance. Additionally, it is clearly demonstrated that this system works likely to sodium-ion batteries and cation intercalation desalination, with Na+ intercalation at the cathode and Na+ deintercalation at the anode during discharging, but charged by salinity gradients instead of electrical power.

Publication Source (Journal or Book title)

ChemistrySelect

First Page

5571

Last Page

5580

This document is currently not available here.

Share

COinS