Self‐discharge in supercapacitors. Part II: Factors influencing it and mitigation

Supercapacitors have emerged as drivers for the advancement of green energy technologies in energy storage systems and energy‐efficient devices. Their ability to rapidly acquire and deliver charge at high current densities and long cycle life is key. However, their high self‐discharge rate prevents their potential use in a wide range of applications, especially when utilizing commonly available activated carbon electrodes. Addressing this bottleneck is hindered by the lack of a comprehensive understanding of the discharge process. In this review, we delve into a comprehensive review of factors (temperature, initial voltage, charging conditions, history, functional groups, pore geometry, and the impurities present) that influence self‐discharge in supercapacitors and attempts made in the literature on its mitigation (electrode, electrolyte, and separator modification). This article is categorized under: Emerging Technologies > Energy Storage