Enhancing hydrovoltaic power generation through heat conduction effects

Abstract

Restricted ambient temperature and slow heat replenishment in the phase transition of water molecules severely limit the performance of the evaporation-induced hydrovoltaic generators. Here we demonstrate a heat conduction effect enhanced hydrovoltaic power generator by integrating a flexible ionic thermoelectric gelatin material with a porous dual-size Al2O3 hydrovoltaic generator. In the hybrid heat conduction effect enhanced hydrovoltaic power generator, the ionic thermoelectric gelatin material can effectively improve the heat conduction between hydrovoltaic generator and near environment, thus increasing the water evaporation rate to improve the output voltage. Synergistically, hydrovoltaic generator part with continuous water evaporation can induce a constant temperature difference for the thermoelectric generator. Moreover, the system can efficiently achieve solar-to-thermal conversion to raise the temperature difference, accompanied by a stable open circuit voltage of 6.4 V for the hydrovoltaic generator module, the highest value yet.

Materials for evaporation‐driven hydrovoltaic technology

“…Real‐time voltage changes of the hydrovoltaic module and thermoelectricity module under one sun irradiation, respectively. [ 33 ] Copyright 2022, Springer.…”

“…This ingenious design was a major step forward in the development of improved output voltage for hydrovoltaic devices. [ 33 ]…”

“…[ 64 ] When changed the mass ratio of m200:m20 to 50:1 (m200 and m20 are the mass of 200 and 20 nm Al 2 O 3 , respectively), the maximum V oc , I sc , and power density of the EHD with the same size increased to 1.34 μA, 4 V, and 0.046 μW/cm 2 , respectively. [ 33 ] However, filling the voids with excessive 20 nm Al 2 O 3 particles (m200:m20 ≤ 5:1) could significantly reduce the channel size, increase the flow resistance of water in the channel, and bring a large number of cracks, thereby reducing the device performance. Therefore, it is important to find a balance between the channel size and flow resistance to achieve maximum power output.…”

“…(L) Reproduced with permission. [ 33 ] Copyright 2022, Springer. GO, graphene oxide; LDH, layered double hydroxide; MOF, metal‐organic framework; PET, polyethylene terephthalate; rGO, reduced graphene oxide.…”

Graphene oxide as a versatile platform for emerging hydrovoltaic technology

“…10,11 Thus, a hydrovoltaic generator is developed, which provides a new method to obtain energy from water. 12,13 .…”