Saving electric energy by integrating a photoelectrode into a Li-ion battery

Abstract

We here report a novel photoassisted chargeable Li-ion battery (LIB) consisting of a LiFePO₄ cathode, a lithium anode and a TiO₂ photoelectrode coupled with an iodide (I⁻) ion redox shuttle for saving electric energy. Due to the contribution of the photovoltage, the photocharging voltage of the LiFePO₄ cathode is reduced to 2.78 V, which is lower than the discharge voltage of 3.41 V, resulting in ∼20% electric energy saving. This new conceptual design will provide a possible route for direct conversion and storage of solar energy in LIBs.