Seawater-Mediated Solar-to-Sodium Conversion by Bismuth Vanadate Photoanode- Photovoltaic Tandem Cell: Solar Rechargeable Seawater Battery

Abstract

Conversion of sunlight to chemical energy based on photoelectrochemical (PEC) processes has been considered as a promising strategy for solar energy harvesting. Here, we propose a novel platform that converts solar energy into sodium (Na) as a solid-state solar fuel via the PEC oxidation of natural seawater, for which a Na ion-selective ceramic membrane is employed together with photoelectrode (PE)-photovoltaic (PV) tandem cell. Using an elaborately modified bismuth vanadate-based PE in tandem with crystalline silicon PV, we demonstrate unassisted solar-to-Na conversion (equivalent to solar charge of seawater battery) with an unprecedentedly high efficiency of 8% (expected operating point under 1 sun) and measured operation efficiency of 5.7% (0.2 sun) and long-term stability, suggesting a new benchmark for low-cost, efficient, and scalable solid solar fuel production. The sodium turns easily into electricity on demand making the device a nature-friendly, monolithic solar rechargeable seawater battery.

Halide Perovskite Materials for Energy Storage Applications

“…[ 10,11 ] The halide perovskite materials share unique properties including tunable bandgap, superior solar energy harvesting performance, and ambipolar properties with a facile and cost‐effective fabrication method, which enable various optoelectronic and solar energy conversion applications. [ 12–19 ]…”

A short review on graphene derivatives towards photoelectrochemical water splitting

“…Its broad optical absorption spectrum, spanning from ultraviolet to visible wavelengths, facilitates the effective utilization of various solar photons [23]. This property positions GO as a promising candidate for solar-driven applications, wherein the photoanode's ability to adeptly harness solar energy holds paramount importance, such as in photovoltaics and photoelectrochemical water splitting [24].…”

Dual‐Use of Seawater Batteries for Energy Storage and Water Desalination

“…designed a combined photoelectrode (PE)– photovoltaic (PV) device to accomplish the solar energy‐driven rechargeable seawater batteries. [ 193 ] In the cell, NiFeO x /H, 1% Mo:BiVO 4 , and a series‐connection of crystalline silicon solar cells or lead halide perovskite solar cells were applied as the cathode, and the other components were adopted from conventional rechargeable seawater batteries (Figure 8C). Oxygen and hydrogen are obtained during the charging process on the cathode side, while on the anode side, the sodium ions precipitate as metallic sodium, as shown in Figure 8D.…”