Enhancing the electrokinetic energy conversion performance with a high dielectric membrane channel

Nanofluidic electrokinetic energy conversion is widely regarded as a promising, environmentally friendly, and simple power generation technology. However, previous research has predominantly focused on electrolyte solution regions, with little consideration of the impact of solid membrane properties. In this work, the ion transport model in the dielectric membrane channel was established, and the effects of dielectric constant, salt concentration, solution pH, and pore size on the electrokinetic energy conversion performance were investigated. The results demonstrate that the permittivity, salt concentration, solution pH, and nanopore size jointly influence the surface charge density. The presence of dielectric membranes expands the range of electric field intensity, enhancing the electrostatic interactions and favoring improved electrokinetic energy conversion performance. In particular, under low concentration conditions, the energy conversion efficiency with a dielectric membrane channel is 1.26 times higher than that without a dielectric membrane channel. Furthermore, with increasing salt concentration, output power and conversion efficiency initially increase before decreasing. Increasing solution pH is detrimental to enhancing output power and conversion efficiency. Enlarging nanopore size facilitates higher output power but hinders improvement in conversion efficiency. These results provide valuable insight for designing and optimizing practical nanofluidic energy conversion devices.