2021 Nat. Commun.: SOEE 15.4%! New formation of SFB promotes the development of practical solar cells
Top-Notch Due to It’s Precision!
Nature Communications (IF 14.919) published the research by Song Jin from the University of Wisconsin-Madison, Jr-Hau He from City University of Hong Kong and others in January 2021. The increasing demand for clean and renewable energy has stimulated the development of intermittent energy-solar simultaneous conversion and storage. Among them, if the hydrogen and reduction of carbon dioxide produced by solar-driven photoelectrochemical (PEC) water splitting are used as the production of fuels, they can be used to harvest solar energy and store it as chemical energy. However, practical PEC technologies still have problems such as poor stability of many photoelectrode materials under PEC conditions, and the need for additional fuel cell devices to regenerate electricity from solar fuels. Therefore, solar flow batteries (SFB) produced by monolithically integrate photovoltaics (PVs) or regenerative PEC cells and redox flow batteries (RFBs) have become an alternative method to solve the difficulties of conventional PEC devices.
However, it has recently been proved that the high solar-to-output electricity efficiency (SOEE) in SFBs, the complex multi-junction photoelectrodes used are not desirable for practical applications. In this study, the authors propose a more stable and efficient integrated SFB, which is composed of a back-illuminated single-junction GaAs photoelectrode with an n-p-n sandwiched design.
Schematic design of the SJ-GaAs solar cell and the SFB device and its PV performance.
Enlitech’s QE-R Quantum Efficiency Measurement system and other instruments were used in this study to characterize the solar cells. It was found that the rational potential matching simulation and operating condition optimization of GaAs SFB made the SOEE of the single-junction SFB devices reach 15.4%. In addition, the TiO2 protective layer and the powerful redox couples in neutral pH electrolyte enable the SFB to achieve stable cycle over 408h (150 cycles). These results have prompted the use of more practical solar cells with higher photocurrent densities but relatively lower photovoltages for high-performance SFB. It is expected to realize off-grid electrification applications, such as solar home systems, to expand new paths for the further development of practical SFBs.
The quantum efficiency measurement system is used for EQE (external quantum efficiency) spectral analysis of perovskite solar cells. It also provides a comparison of Jsc (short-circuit current density) for the short-circuit current of solar cells under sunlight to prove the experimental results.
The potential matching simulation and the characteristics of SFB cycling. (c) Cell potential (blue) and photocurrent density (red) vs. time of the integrated SFB device during cycling. An impressive average SOEE of 15.4% for 10 cycles of SFB cycling by using the BTMAP-Fc and NMe-TEMPO redox couples.
SFB performance in comparison with representative previous works.