Fabrication of Pressure-Responsive Energy Device from Nanofluidic Vanadium Pentoxide and Polymeric Hydrogel

Owing to their unique advantages like environmental compatibility, low cost, and high energy density, metal–water batteries are gaining a great deal of attention. The principles of metal–water batteries were applied here to develop a sustainable pressure-responsive energy delivery system. Application of a gentle pressure of 56 kPa on agar and a glycerol-based hydrogel membrane sandwiched between the aluminum foil and the nanofluidic V₂O₅ membrane (Al-gel-VO device) generates open-circuit voltage up to 1.3 V accompanied by an output current of 85 μA (power density = 0.45 W m^–2). The output power of Al-gel-VO can be further improved by tuning parameters like lateral dimensions of the layers, applied pressure, and ionic conductivity of the gel membrane. Remarkably, under ambient conditions, the hydrogel and V₂O₅-based devices can provide a constant potential difference up to five consecutive days. Unlike typical humidity-powered energy systems, the energy output of the current device is resistant to the diurnal variations in environmental conditions. Remarkably, both gel and V₂O₅ membranes can be completely regenerated after damage caused by prolonged use or accidents without any deterioration in the energy efficiencies. Moreover, the Al-gel-VO devices can also be connected in series (or parallel) to add up the voltage (or current) values of the individual devices.