An efficient and stable solar flow battery enabled by a single-junction GaAs photoelectrode

Abstract

Converting and storing solar energy and releasing it on demand by using solar flow batteries (SFBs) is a promising way to address the challenge of solar intermittency. Although high solar-to-output electricity efficiencies (SOEE) have been recently demonstrated in SFBs, the complex multi-junction photoelectrodes used are not desirable for practical applications. Here, we report an efficient and stable integrated SFB built with back-illuminated single-junction GaAs photoelectrode with an n-p-n sandwiched design. Rational potential matching simulation and operating condition optimization of this GaAs SFB lead to a record SOEE of 15.4% among single-junction SFB devices. Furthermore, the TiO2 protection layer and robust redox couples in neutral pH electrolyte enable the SFB to achieve stable cycling over 408 h (150 cycles). These results advance the utilization of more practical solar cells with higher photocurrent densities but lower photovoltages for high performance SFBs and pave the way for developing practical and efficient SFBs.

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

“…Compared with connecting high-cost photovoltaic and battery modules, SPRBs store solar energy by driving nonspontaneous reversible redox reactions in PEC cells through photoelectrode materials. [89,163,164] And delivering energy through reverse electrochemical reactions in the same device is much more cost-effective. [165,166] In order to obtain high conversion efficiency and high durability, photoanode with suitable energy level (energy level matching) needs to be considered when designing integrated photoelectrodes to meet the requirements (light harvesting efficiency and charge separation efficiency) of different devices.…”

Photo-Rechargeable Li-Ion Batteries: Device Configurations, Mechanisms, and Materials

“…Several other PB devices based on redox flow batteries, − Na-ion, K-ion, and Zn-ion batteries − have also been developed in the recent past, and a few review articles have broadly described developments in the field of PBs as well as photocapacitors, redox flow batteries, and other metal-ion (Na + , Zn + , and Al + ) battery technologies. − However, given the industrial relevance and practical advantages of Li-ion batteries mentioned above, this review focuses only on the recent and significant developments of Li-ion based PBs by describing their classifications, device configurations, materials, and working mechanisms in detail. This review briefly sketches the evolution that PB devices have gone through recently and projects future trends and the opportunities offered by bringing the knowledge and techniques from the fields of battery and solar cell research together.…”

Highly Active Hollow Porous Carbon Spheres@Graphite Felt Composite Electrode for High Power Density Vanadium Flow Batteries

“…[ 1 ] However, the intermittency and volatility of renewable energies like solar and wind power call for large‐scale energy storage devices. [ 2–4 ] Among various electrochemical energy storage technologies, a flow battery, vanadium flow battery (VFB) in particular, is widely considered as one of the most ideal large‐scale energy storage technologies due to its attractive features of design flexibility, high safety, long cycle life, and high energy efficiency. [ 5–8 ] Heretofore, numerous megawatt‐level VFB systems have been already implemented in operation in different application scenarios.…”