Healable Liquid-Free Osmotic Power Generator Using Nanofluidic Membranes of 2D Vanadium Pentoxide Nanosheets

Here, we report an osmotic power generator (OPG) using a restacked membrane of vanadium pentoxide (V₂O₅) nanosheets and an ion-infused gelatin hydrogel. This gel osmotic power generator (GOPG) has several advantages over traditional liquid-based OPG in portability, power output, and spillage safety. Under a 1000-fold salinity gradient, the GOPG achieved an output power density of 0.13 W m^-2. We have studied the effect of different ions, the concentration gradient, and the membrane thickness to achieve maximum power output. Notably, physical damage to the V₂O₅ membrane can be healed by adding a drop of water. Cracks or damage to the gelatin gel can be healed by reheating and cooling. The GOPGs can be easily connected in series and/or parallel to add up the voltage and/or current values generated by individual devices for practical powering applications. We have demonstrated lighting up an LED and powering a humidity meter using a series of combinations with the GOPG.