电解质种类对锥形纳米通道中动电能量转换特性的影响

Pressure-driven electrokinetic energy conversion in nanochannels has the ability of directly converting the hydrodynamic energy to the electric power, which is a clean and renewable way for electricity generation. Considering the nanochannels fabricated with nonuniform cross-section, this paper focuses on a typical nanochannel of nonuniform cross-section, i.e., conical nanochannel, and solves the coupled multiphysical fields governing the electrokinetic energy conversion in nanochannel with the numerical simulation, and then thoroughly discusses the effects of electrolyte (LiCl, NaCl, KCl) and nanochannel conicity on the electrokinetic energy conversion and the regulation effects of the performance parameters. The study found that the aqueous electrolyte solution with a smaller cation diffusion coefficient under the conditions of a forward pressure difference and a small channel conicity can achieve a higher value of the energy conversion efficiency, e.g., the energy conversion efficiency of LiCl solution is 0.85%, which is higher than NaCl solution (0.7%) and KCl solution (0.53%). The conclusions from this study are of significance for the selection of the electrolytes, the serial or parallel configuration and the direction of applied pressure difference during the design and operation of electrokinetic energy conversion devices.