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.