High-efficiency perovskite/silicon tandem solar cells combine with aqueous organic redox flow batteries to form a high-performance, stable solar flow battery device. The technology developed by an international research team facilitates the collection and storage of solar energy in one system.

Solar flow batteries marry the merits of photovoltaic cells that convert sunlight into electricity with the advantages of flow batteries, which use tanks of reactive chemicals to produce electricity and are recharged by The integrated solar flow battery contains both a solar cell and chemicals to generate, store and redeliver renewable electricity from the sun in one device. Source: Wenjie Li/University of Wisconsinsolar cells. To assemble the system, perovskite-silicon solar cells were designed with an additional protection layer on the silicon surface, and two organic compounds dissolved in saline solution were selected for the flow battery reactants on the basis of theoretical modeling.

A solar-to-output electricity efficiency of 20% over hundreds of hours and hundreds of charge-discharge cycles was documented for the solar flow batteries. Improved device lifetime, solar power conversion utilization ratio and capacity utilization rate were also demonstrated.

The researchers plan to continue advancing solar flow batteries to improve efficiency, reduce costs and investigate ways to scale them up for practical large-scale use. Scientists from the University of New South Wales (Australia), University of Sydney (Australia), University of Wisconsin, Utah State University, City University of Hong Kong and King Abdullah University of Science and Technology (Saudi Arabia) contributed to this development.