Monitoring the Electrochemical Energy Storage Processes of an Organic Full Rechargeable Battery via Operando Raman Spectroscopy - A Mechanistic Study

The green, sustainable and versatile nature of using organic compounds that can be derived from biomass makes them extremely interesting materials for use in various rechargeable batteries. However, the overall electrochemical reaction mechanism of an organic full rechargeable battery has seldom been reported due to the lack of straightforward and accessible analytical techniques capable of probing the rechargeable battery system in real-time. Herein, we configured an organic full rechargeable battery composed of a porphyrin-metal complex [5,15-bis-(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP) anode, a graphite cathode and a 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI) ionic liquid electrolyte. Operando Raman spectroscopy was employed to simultaneously monitor the evolution of Raman bands from the anode, cathode and electrolyte of the battery caused by electrochemical energy storage (EES) processes. It was found that during EES processes, the electronic structural ch...