Investigation of Performance Difference between Photo‐Charging and Conventional Constant Current Charging for Energy Storage Batteries

Abstract Solar cells offer clean and abundant power sources for directly photo‐charging rechargeable batteries, which shows great potential for the development of integrated power supply. In order to deepen the understanding of the novel type of charging process, this research takes silicon solar cells and lithium cobalt oxide batteries as examples to compare the performance difference between photo‐charging and conventional constant current charging in detail. Surprisingly, the photo‐charging turns out to be superior in charging efficiency, polarization mitigation, and cyclic performance even with the intrinsic instability of the solar cells when compared with constant current charging mode. Finally, this research optimizes the calculation method of energy storage efficiency in the integrated power supply by calculating the actual power during the photo‐charging process by recording the voltage and current change with time. Besides, the power matching degree is quantified by the ratio of to η₁, providing new ideas for the matching method of solar cells and rechargeable batteries in integrated power supplies.