Effect of Flow Rate or Pressure on the Potential of Tungsten Oxide Placed in Flowing Liquid

In this study, based on the phenomenon of solid-liquid electricity generation, the core sensitivity of tungsten oxide in flowing liquids is verified to be the liquid pressure rather than the flow rate by designing asymmetric and symmetric system experiments. The tungsten oxide electrode is also calibrated with a high-precision resistive liquid pressure sensor, and the sensitivity of the tungsten oxide liquid pressure sensor is found to be 0.18949 (V/kPa). Meanwhile, the Nyquist plots of the tungsten oxide electrode at different liquid pressures are obtained using the electrochemical impedance spectroscopy testing technique, and the equivalent circuit model of electrical double layer (EDL) on the tungsten oxide/liquid interface is derived. It is further revealed that the higher the liquid pressure, the thinner the thickness of EDL on the tungsten oxide/liquid interface and the lower the output potential of the tungsten oxide. This not only enriches the application of solid-liquid electricity generation in self-powered sensing, but also provides strong evidence for EDL theory in solid-liquid electricity generation.