Advances and Challenges in Photoelectrochemical Redox Batteries for Solar Energy Conversion and Storage

Abstract

The photoelectrochemical redox battery (PRB) has been regarded as an alternative candidate for large‐scale solar energy capture, conversion, and storage as it combines the superior advantages of photoelectrochemical devices and redox batteries. As an emerging solar energy utilization technology, significant progress has been made towards promoting and proliferating the practical applications of PRBs. However, wide market penetration of PRBs is still being significantly inhibited by limited photocatalytic activity, low efficiency, among other critical issues. Furthermore, the integration of each component, including solar materials, redox couples, and membranes and their interaction in PRBs play vital roles towards achieving smooth operation and high performance. Herein, the materials, mechanisms, recent advances, and challenges in the use of PRBs are presented. The crucial influence of redox couples, photoelectrode materials, membranes on the performance of the system including how they affect solar energy capture, reaction kinetics, and internal losses are systematically discussed. In addition, the recent advances of a single‐battery of photoelectrode mode and an integrated device of solar cell mode are summarized. Furthermore, the state of the art performance of PRBs and their upscaling progress are also discussed. Finally, the challenges and perspectives for the future development of PRBs are highlighted.

Integrated Photovoltaic Charging and Energy Storage Systems: Mechanism, Optimization, and Future

“…In addition to the above-mentioned high matching of photoelectrode materials, another core issue is that photoelectrodes must possess good PEC properties, including high light absorption, fast charge separation/transfer, and energy level matching, in order to realize high-efficiency photovoltaic cells (Figure 6a). [60,82] High light absorption in the visible light region is a process that utilizes light energy to generate more photocarriers and promotes redox reactions in photocells; [13] fast charge separation/transfer can generate efficient holes and electrons, reducing The recombination of holes and electrons improves the stability of electrode cycling and accelerates the reaction; [83] suitable energy level matching can increase the photocurrent, reduce the electron transfer resistance and expand the energy density. [84] Therefore, in order to accelerate the industrial application of high-efficiency photovoltaic cells, we will analyze and summarize the above three optimization mechanisms in detail.…”

“…In DSSC, the dye absorbs light to form excitons, which then generate charges at the semiconductor-dye interface, with the semiconductor and electrolyte acting as charge transport materials. [58,60,61] Therefore, the overall efficiency of DSSC depends on the optimization and compatibility of each of its components. [62,63] In order to improve the overall efficiency of DSSC, it can be carried out from the aspects of modifying the dye ligands and optimizing the integrated device of the dye/electrode overall.…”

“…device and the load of the dye in SPRBs. [60,86] Therefore, nanostructured photoelectrodes are usually used. In SPRBs, most photogenerated carriers disappear due to recombination when illuminated.…”

“…The rational design of the photovoltaic cell structure is beneficial to avoid problems such as mismatch between energy levels, carrier transport, reaction kinetics, and effective light absorption, and low efficiency. [60,141,142] In addition, a reasonable structural system can expand its applicable conditions, increase the universal scope of SPRBs, and provide favorable support for the next generation of efficient and functional SPRBs systems. Therefore, in this chapter, we give detailed analytical summaries from liquid and solid bases, which are summarized in tables at the end of this paper (Table 1).…”

Solar Energy Storage in an All-Vanadium Photoelectrochemical Cell: Structural Effect of Titania Nanocatalyst in Photoanode

“…In comparison with the solar to hydrogen conversion, the use of a photoelectrochemical cell (PEC) to convert solar energy to electrochemical energy in the redox couples also allows efficient storage of solar energy because of the unique potentials for both the oxidation and reduction reactions [10][11][12]. Among those reversible redox pairs in the PECs, the + /VO 2+ and V 3+ /V 2+ pairs have been considered as competitive candidates for solar energy storage due to the following merits, including the large storage capacity, the avoidance of electrolyte cross-contamination, the fast electrochemical reaction kinetics [13][14][15][16].…”