Faradaic and Non‐Faradaic Self‐Discharge Mechanisms in Carbon‐Based Electrochemical Capacitors

Abstract Electrochemical capacitors (ECs) play a crucial role in electrical energy storage, offering great potential for efficient energy storage and power management. However, they face challenges such as moderate energy densities and rapid self‐discharge. Addressing self‐discharge necessitates a fundamental understanding of the underlying processes. This review sets itself apart from other reviews by focusing on the basic principles of self‐discharge processes in carbon‐based ECs, particularly examining the nature of the process and the involvement of redox reactions. This study delineates the potential conditions for various self‐discharge processes and proposes plausible criteria for differentiation, complemented by mathematical modeling. Additionally, the model selection, curve fitting, and effective tuning methods are explored to control self‐discharge processes.