Mitochondrial Bioenergy Transformation: The Discharge/Charge Reaction of Vitamin B2 in Lithium-Ion Batteries

Organic electrode materials are progressively becoming a research hotspot for energy storage materials due to their renewable and environmentally friendly features. Inspired by the energy transduction mechanism of flavin adenine dinucleotide (FAD) on the inner mitochondrial membrane of living organisms, the lithium storage electrochemical behavior of riboflavin (RF, vitamin B2) in lithium-ion batteries (LIBs) has been explored. The students are encouraged to find inspiration from organisms to design energy storage materials. This course is used to teach the principles of energy storage devices and the electrochemical mechanism of organic small molecules for upper-division undergraduates. This novel theory and experiment module is suitable for students with a foundation of computational chemistry, physical chemistry, and modern testing technology. The redox reaction mechanism of RF with multiple active sites is clarified through density functional theory (DFT) calculations. The LIBs assembled by the students are evaluated by using a battery testing system with electrochemical methods. The relative potentials calculated by DFT for the stepwise lithiation reactions are consistent with the reduction peak potential of the cyclic voltammetry and the plateau potential of the discharge curve, which demonstrates the rationality of the proposed electrochemical reaction mechanism. These findings confirm the expectation of using bioinspired redoxactive moieties for LIBs and the development of organic electrode materials. The course can increase students' interest in the field of organic active materials and renewable energy.