Unwanted degradation in pseudocapacitors: Challenges and opportunities

Lithium-ion batteries and supercapacitors are commonly used for energy storage, but their ability to provide high power and high energy density simultaneously is limited. Pseudocapacitors offer a potential solution to this problem and have received significant attention in recent years. In this review, we delve into the development of pseudocapacitors, including an examination of degradation mechanisms at the microstructure, electrode, and cell levels. Our analysis of different examples shows that the materials used for the electrode and the manufacturing process are critical factors that contribute to degradation. Additionally, the electrolyte used plays an important role in slowing down the rate of degradation. These findings suggest that pseudocapacitors could be one of the most stable energy storage devices during cycling and could help optimize material selection and design not only for pseudocapacitors but also for batteries and supercapacitors.

Automated summary

Lithium-ion batteries and supercapacitors have limitations in simultaneously providing high power and high energy density. Pseudocapacitors offer a potential solution to this issue and have gained significant attention in recent years. This review explores the development of pseudocapacitors, including an examination of degradation mechanisms at various levels. The findings show that the materials and manufacturing process of the electrode, as well as the choice of electrolyte, play crucial roles in degradation. Pseudocapacitors could be a stable energy storage option during cycling and contribute to improving material selection and design for not only pseudocapacitors but also batteries and supercapacitors.