Kinetically driven switching and memory phenomena at the interface between a proton-conductive electrolyte and a titanium electrode

Numerous studies have examined the switching properties of semi- or ion-conductors and isolators; however, most of these have focused on the ohmic resistance characteristics. Here, we report a new type of polarity-dependent switching phenomenon obtained for electrical devices with the configuration: metal working electrode│Si0.97Al0.03H0.03P2O7-polytetrafluoroethylene composite electrolyte│Pt/C counter electrode. The counter electrode is reversibly active for the water vapor oxidation and evolution reactions. The composite electrolyte exhibits high withstanding voltage capability in the bias voltage range of ±7 V. When titanium was employed as the working electrode, the anodic polarization resistance was approximately two orders of magnitude greater than the cathodic polarization resistance. The ohmic resistance of the device was almost unchanged, regardless of the bias voltage polarity. Moreover, kinetically induced high-resistance/low-resistance states could be cyclically switched through positive/negative bias voltage pulses, and these states were also confirmed to be memorized at open circuit.