Optoelectronic and photo-charging properties of CH3NH3PbI3/LiFePO4 system

Summary The photo-responsive capability of lithium battery materials is a prerequisite to realize new-generation light-weight photo-rechargeable batteries. However, the photo-charging property is not available for common battery electrode materials such as LiFePO 4 . In this manuscript, we provide evidence that the halide perovskite material CH 3 NH 3 PbI 3 is able to activate the photo-charging properties of the lithium-ion battery electrode material LiFePO 4 . The photoelectrochemical measurement demonstrates that the photo-responsive property of the CH 3 NH 3 PbI 3 /LiFePO 4 composite is significantly improved; the photo-induced signals are neither observed in the individual halide perovskite nor the lithium battery material tested under the same condition. The first-principles calculations reveal strong interactions between the CH 3 NH 3 PbI 3 layer and the LiFePO 4 layer via the coordination between the Lewis acid and Lewis base species; this forms a heterostructure that assists the photo-charging process. We propose that the combination of halide perovskite materials and lithium battery electrode materials is a viable way to achieve light-weight photo-batteries. Suggestions to address the stability and voltage issues of the halide perovskite-based hybrid systems toward the photo-battery application are provided. This study facilitates the fundamental understanding of the integrated photo-rechargeable battery materials and highlights the importance of halide perovskite materials for the lithium-ion and photo-rechargeable batteries.