Recent Research in the Development of Integrated Solar Cell Supercapacitors

Recent research on synergistic integration of photoelectric energy conversion and electrochemical energy storage devices has been focused on achieving sustainable and reliable power output. The energy conversion device (solar cells), when integrated with energy storage systems such as supercapacitors (SC) or lithium-ion batteries (LIBs), can self-charge under illumination and deliver a steady power supply whenever needed. This review highlights the progress in the development of various self-charging power packs with a supercapacitor as an energy storage system in detail. This integrated assembly is often referred to as a self-charging power pack, photocapacitor, or solar capacitor. Herein, a supercapacitor is chosen as the energy storage unit, since it is capable of providing high power density and long-term stability. In order to utilize these power packs in practical applications, various factors are considered, including overall energy conversion efficiency, fabrication techniques, safety, and the cost of the device. In the present review, various device configurations, operation mechanisms, and performance of several photocapacitors are presented. Finally, the existing challenges and limitations of self-charging power packs are elaborated.