Light Rechargeable Lithium-ion Batteries Using V2O5 Cathodes

Abstract

Solar energy is one of the most actively pursued renewable energy sources, but like many other sustainable energy sources, its intermittent character means solar cells have to be connected to an energy storage system to balance production and demand. To improve the efficiency of this energy conversion and storage process, photo-batteries have recently been proposed where one of the battery electrodes is made from a photo-active material that can directly be charged by light without using solar cells. Here, we present photo-rechargeable lithium-ion batteries (Photo-LIBs) using photocathodes based on vanadium pentoxide nanofibers mixed with P3HT and rGO additives. These photocathodes support the photo-charge separation and transportation process needed to recharge. The proposed Photo-LIBs show capacity enhancements of more than 57% under illumination and can be charged to ~ 2.82 V using light and achieve conversion efficiencies of ~ 2.6% for 455 nm illumination and ~ 0.22% for 1 sun illumination.