Influence of the Lithium-Ion Concentration in Electrolytes on the Performance of Dye-Sensitized Photorechargeable Batteries

Abstract

Dye-sensitized photorechargeable batteries (DSPBs) haverecentlygained attention for realizing energy recycling systems under dimlight conditions. However, their performance under high storage efficiency(i.e., the capacity charged within a limited time) for practical applicationremains to be evaluated. Herein, we varied the lithium (Li)-ion concentration,which plays a dual role as energy charging and storage components,to obtain the optimized energy density of DSPBs. Electrochemical studiesshowed that the Li-ion concentration strongly affected the resistancecharacteristics of DSPBs. In particular, increasing the Li-ion concentrationimproved the output capacity and decreased the output voltage. Consequently,the energy density of the finely optimized DSPB improved from 8.73to 12.64 mWh/cm(3) when irradiated by a 1000-lx indoor light-emitting-diodelamp. These findings on the effects of Li-ion concentrations in electrolyteson the performance of DSPBs represent a step forward in realizingthe practical application of DSPBs.