A highly efficient perovskite photovoltaic-aqueous Li/Na-ion battery system

Batteries coupled to photovoltaic (PV) modules have been identified as a viable power source for independent “internet of things” portable electronic devices and to reduce the grid load during peak times. However, the poor matching of these systems can adversely affect the power conversion efficiency, safety, and cost due to increased charge control strategies and supporting load management equipment. In this work, we significantly improve the rate performance of the battery electrodes by asphalt-derived carbon coating, and strategically couple high-efficiency n-i-p type perovskite solar cells with either aqueous lithium or sodium (Li/Na)-ion batteries, for the first time, to create a low-cost and high-performance photovoltaic battery system. Both photovoltaic battery systems demonstrate stable cycling performance for at least 30 cycles. We also demonstrate a high energy-conversion and storage efficiency of about 9.3% at a high discharge rate of 2 C and show that this is significantly superior than previously integrated photovoltaic battery systems. We suggest that the enhanced power and efficient energy transfer between the perovskite solar cells and aqueous Li/Na-ion batteries make this system attractive for a wide range of energy needs.