Progress in integrated photo-rechargeable battery technologies

Integrated photo-rechargeable battery systems represent a significant advancement in sustainable energy storage and conversion by combining photovoltaic energy harvesting with direct energy storage in a compact design. Although initially studied in the 1970s, interest in this field has surged in recent years. Due to the multidisciplinary nature of this topic, researchers from diverse backgrounds approach it with varying methodologies, resulting in highly diverse cell designs and inconsistent performance metrics. These variations complicate the comparison and evaluation of system efficiency and functionality. This review presents a comprehensive overview of the field's development and current state, from early photoelectrochemical approaches to modern integrated designs. Additionally, it addresses the challenge of performance evaluation by compiling current approaches to performance measurement and proposing standardized evaluation parameters under defined conditions. This dual focus on field overview and metrics standardization aims to provide both a thorough understanding of solar electrochemical energy storage technologies and a framework for their consistent evaluation, which is critical for advancing these technologies.