Efficient Bifunctional Photoelectric Integrated Cathode for Solar Energy Conversion and Storage

The integrated photoelectric battery serves as a compact and energy-efficient form for direct conversion and storage of solar energy compared to the traditional isolated PV-battery systems. However, combining efficient light harvesting and electrochemical energy storage into a single material is a great challenge. Here, a bifunctional lead phytate-cesium lead bromide (PbPA-CsPbBr₃) cathode is explored for the solid-state batteries in terms of CsPbBr₃ in situ grown on the PbPA framework. Specifically, CsPbBr₃ nanocrystals generate electron-hole pairs under sunlight, the holes contribute to the lithium desorption of the discharged PbPA, and the electrons participate in the formation of the cathode interfacial film through oxygen reduction. The obtained solid-state photoelectric lithium-metal battery achieved a photoconversion efficiency of 0.72%, outperforming other systems under the same lighting conditions. The reasonable cathode design and its application in integrated solid-state batteries provide an efficient way for solar energy utilization.