Carbonized peat moss electrodes for efficient salinity gradient energy recovery in a capacitive concentration flow cell
Document Type
Article
Publication Date
1-20-2019
Abstract
The globally extractable salinity gradient (SG) energy from the mixing of seawater and river water is estimated to be 3% of worldwide electricity consumption. Here we applied carbonized peat moss (CPM) electrodes to a capacitive concentration flow cell that is capable of harvesting SG energy based on the capacitive double layer expansion (CDLE) together with the Donnan potential. The electrodes were made from the visually inexhaustible peat moss by a facile and environmental benign pyrolysis process. With two identical CPM electrodes and a cation-exchange membrane, the cell produced a peak power density of 5.33 W m−2 and an average power density of 950 mW m−2, the highest ever reported for CDLE-based techniques, using synthetic seawater (30 g L−1 NaCl) and river water (1 g L−1 NaCl). The excellent performance was a result of the macroporous structure of the CPM electrodes, the assistance of Donnan potential, and the double-channel structure of the cell. This system was durable as it could extract energy from highly saline water (300 g L−1 NaCl) and it still worked well after 100 cycles. This study provides a new method to efficiently and continuously harvest SG energy based on the CDLE without an external charge.
Publication Source (Journal or Book title)
Electrochimica Acta
First Page
240
Last Page
248
Recommended Citation
Zhu, H., Xu, W., Tan, G., Whiddon, E., Wang, Y., Arges, C., & Zhu, X. (2019). Carbonized peat moss electrodes for efficient salinity gradient energy recovery in a capacitive concentration flow cell. Electrochimica Acta, 294, 240-248. https://doi.org/10.1016/j.electacta.2018.10.053