Abstract
In recent years, a series of electrochemical-based systems known as CAPMIX has been proposed as a method to capture salinity gradient energy from mixing of fresh and saline water. Among them, membrane-less Capacitive energy extraction based on double layer expansion (CDLE) is a promising technique owing to its active material’s relative low-cost and high durability. In this study, the author analyzed the relationship of 3 different parameters: geometric surface area of the electrode, active material on the electrode and charging potential to the performance of CDLE. The experiments was planned using Box-Behken Design approach and Surface Response Methodology was adopted to analyzed data. Based on the empirical model, the importance of each factors for energy extraction are as follow: the mass of active material, the charging potential and geometric surface area. The optimum operating condition for activated carbon based CDLE is 12.4 mg/cm2, 461 mV with an energy extraction of 7.00 mJ per cycle. The author also explored the feasibility of carbon hollow sphere as the electrode material of CDLE, but concluded that carbon hollow sphere suffers large charge leakage owing to its larger pore size.