Salinity‐Difference‐Driven Power Generation by a Hybrid Capacitive Approach

The extraction of salinity gradient energy remains a challenging task. In this paper, we propose a new method for the extraction of salinity gradient energy by using a hybrid capacitor, which consists of a battery electrode and a porous carbon electrode. The potentials of the Na4Mn9O18 (NMO) and activated carbon (AC) electrodes show opposite dependencies on salt concentration, so that as fresh water and salt water flow alternately through the hybrid capacitor, the voltage difference between the electrodes can be increased by 110 mV. Our results demonstrate the viability of this new method to harvest salinity gradient energy without using membranes or precious metals.