Because of the intermittent nature of solar radiation, being able to simultaneously convert and store solar energy is a significant advance for efficiently harnessing solar energy. Solar fuels have already been recognized as a promising method towards this goal and have attracted tremendous research interest recently. Alternatively, this goal can also be achieved by using the solar-powered electrochemical energy storage (SPEES) strategy, which integrates a photoelectrochemical cell and an electrochemical cell into a single device. The integrated device is able to harvest solar energy and store it in situ within the device via a photocharging process and also distribute the energy as electric power when needed. This essay reviews the past SPEES research and analyzes its future prospects with a special emphasis on chemical design and material choices. We hope that the article will help draw more research attention to this field and stimulate additional exciting investigations toward more efficient solar energy utilization.

Solar-powered electrochemical energy storage: an alternative to solar fuels

Photorechargeable air batteries which discharge by reducing oxygen in the air and which can he charged by light irradiation, are new types of secondary batteries We have investigated recharging this type of battery via the photoelectrochemical reaction that occurs at its metal hydride-semiconductor/electrolyte interface. This paper discusses the photorecharging capability of an air hattery using a metal hydride anode, namely, a SrTiO 3 -LaNi 3.76 Al 1.24 H n |KOH|O 2 cell. We have confirmed that our new negative electrode not only prevents self-discharge hut is also capable of semiconductor hand bending which is the most important requirement for photorecharging We have demonstrated that this battery can be photorecharged and discharged by using a metal hydride electrode and oxygen from air.

A Photorechargeable Metal Hydride/Air Battery

Photoelectrolysis of H2S using an n-CdSe photoanode

An electrochemical apparatus for energy storage and power generation comprises a single cell or an array of unit cells (10), each cell comprising a +ve electrode (12) and a -ve electrode (14) with a dual membrane in each cell dividing it into +ve chambers (22C and 24C) for posilyte and anolyte solutions (22, 24) which are recirculated through separate pumps (26, 28) and storage tanks (32, 34) and back to the chambers. The dual membranes in each cell provide a third chamber (23C) between the +ve chamber (22C) and the -ve chamber (24C), through which an idler electrolyte is circulated. During the operation of the cell, any ionic species which cross the cation exchange membranes, which in an ideal system would remain in either the +ve chamber or the -ve chamber of the cell, will collect in the buffer chamber or chambers.

Electrochemical apparatus for energy storage and/or power delivery comprising multi-compartment cells

Solar Redox Flow Batteries: Mechanism, Design, and Measurement

The authors have determined the diffusion coefficients and fluxes of sulfide and polysulfide species through Nafion membranes in order to correlate the physical properties of these membranes with their actual performance in three-electrode photoelectrochemical storage cells. Diffusion coefficients for sulfide range from about 3 x 10 -9 to 1 x 10/sup 7/ cm/sup 2//sec, depending on the equivalent weight and thickness of the membrane, and the pH of the solution. Diffusion coefficients for polysulfide are considerably lower, and we discuss some reasons. A Nafion 315 membrane was chosen for the first test in the storage system and the results of the test are presented.

P. Bratin

Papers

Transport Properties of Nafion Membranes for Use in Three‐Electrode Photoelectrochemical Storage Cells

Transport properties of nafion membranes for use in three-electrode photoelectrochemical storage cells