Intermittent electro-anaerobic digestion: A flexible alternative solution for renewable energy storage

Intermittent electro-anaerobic digestion (EAD) combines electrochemical regulation with anaerobic digestion, potentially improving the efficiency of biomethane production and achieving efficient storage of renewable electricity. In this process, the electrodes periodically act as electron donors or acceptors, and by regulating the charging and discharging rhythm, the metabolic activity of microorganisms, the electron transfer rate and the community synergy are significantly enhanced. This work critically reviews emerging progress in our understanding of the electron transfer mechanism, the evolutionary patterns of the composite microbial community, electrochemical performance, and biofilm morphology under various intermittent polarization EAD strategies. The potential for low-carbon energy conversion processes within circular bioeconomy systems with industrial applications is emphasized, while perspectives for future engineering optimization are proposed.