Equipment, AAP 2018
Team : RMES, Chimie de la Matière Condensée de Paris
Project leader : Natacha Krins
This project aims at studying the photocharges generated in bifunctional electrodes for Li-ion photorechargeable battery. The future of these batteries mostly relies on achieving a good cyclability and a fast photo-recharge. Both performances strongly depend on an efficient transport of the photo-generated carriers in terms of path, fate, and dynamics. It is important to note that in a bifunctional electrode, the lithium host material also ensures the light harvesting. Therefore, depending of the state of charge of the battery, the material evolves, together with its conversion efficiency. The material dynamic brings great value to the system, however its characterization is complex. We intend to use intensity modulated photocurrent spectroscopy (IMPS) to evaluate the effective diffusion coefficients of the charge-carriers. The determination of the effective lifetime of electrons (before their recombination) will be evaluated using intensity modulated photovoltage spectroscopy (IMVS). The quantum efficiency will also be evaluated (Incident Photon to Current Conversion Efficiency - IPCE). These techniques are used routinely for classical photoelectrodes (in photovoltaics). Here, we intend to specifically design the experiments to study our system at different states of charge.