title: Extraction of Salinity-Gradient Energy by a Hybrid Capacitive-Mixing System.
abstract: Salinity-gradient energy (SGE) is a renewable energy source available wherever two solutions with different salinity mix. Capacitive-mixing (Capmix) is a technology that directly extracts the SG potential through the movements of ions in high- and low-concentration solutions. However, the energy-harvesting performance of Capmix needs further improvement. Herein, a hybrid Capmix that consists of a battery and capacitive electrodes is proposed. In this system, sodium ions and anions are captured/released by the metal oxide and carbon electrodes, respectively. The hybrid Capmix extracted an energy density that was approximately three times higher (130 J m-2) and exhibited a notable power output (97 mW m-2) compared to the previous Capmix using ion-exchange membranes. Furthermore, the hybrid system operated successfully with real river water and seawater. These results suggest that the hybrid Capmix could be a viable option to harvest energy from salinity gradients.
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, Gwanak-gu, Daehak-dong, Seoul, 151-742, Republic of Korea.
authors.forename: Jiho
authors.initials: J
authors.lastname: Lee
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, Gwanak-gu, Daehak-dong, Seoul, 151-742, Republic of Korea.
authors.forename: Hongsik
authors.initials: H
authors.lastname: Yoon
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, Gwanak-gu, Daehak-dong, Seoul, 151-742, Republic of Korea.
authors.forename: Jaehan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Civil and Environmental Engineering, Penn State University, University Park, PA, 16802, USA.
authors.forename: Taeyoung
authors.initials: T
authors.lastname: Kim
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, Gwanak-gu, Daehak-dong, Seoul, 151-742, Republic of Korea.|Asian Insititute for Energy, Environment & Sustainability(AIEES), Seoul National University, Gwanak-gu, Daehak-dong, Seoul, 151-742, Republic of Korea.
authors.forename: Jeyong
authors.initials: J
authors.lastname: Yoon
mesh_terms: D002606:Charcoal / Q000737:chemistry; D025802:Electric Capacitance; D004553:Electric Conductivity; D011211:Electric Power Supplies; D004566:Electrodes; D017895:Manganese Compounds / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D016062:Porosity; D054712:Salinity
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D002606:Charcoal; C027424:manganese oxide
keywords: capacitive mixing; electrochemistry; energy conversion; salinity-gradient energy; sodium manganese oxide