Numerical Simulation of Micro Power Generation Driven by Ion Transport in Carbon Nanotube Composite Paper

Abstract

Carbon nanotube (CNT) composite paper has been proposed and is expected to be applied to micro-power generation. The composite paper generates electricity when a drop of pure water or an inorganic salt solution such as hydrochloric acid penetrates into the composite paper. However, the mechanism of power generation has not been fully clarified. In this study, an ion transport model in CNT composite paper was established and its micro-power generation characteristics were clarified by time-dependent one-dimensional numerical simulation. Results showed that the electromotive force is generated by the space charge generated near the liquid-composite paper interface. Furthermore, it was shown that under low flow velocity conditions, the space charge near the interface increases due to polarization caused by diffusion, which results in an increase in electromotive force. It was also clarified that higher concentrations of hydrochloric acid enhances output power.