The increasing demand for rapid-charging, long-life energy storage in electric mobility, wearable electronics, and grid systems has expedited the development of supercapacitors. Carbon-based electrodes continue to lead the field due to their tunable porosity, high conductivity, and structural stability. However, challenges such as low energy density, sluggish ion transport in thick electrodes, and restacking of low-dimensional nanocarbons remain major bottlenecks. While much research focuses on understanding charge-storage mechanisms and improving carbon architectures, there is limited discussion of functionalization strategies, the role of heteroatoms, and the integration of carbon-based pseudocapacitive components into scalable devices. This review provides a critical overview of recent advancements in carbon electrode engineering strategies from the last two to three years. The discussions link structure–property relationships across zero- to three-dimensional architectures, highlighting transformative approaches such as hierarchical pore design, binder-free architecture, and flexible device integration. This review also covers sustainable carbon sources, scalable fabrication routes, and synergy between electric double-layer and pseudocapacitive contributions. Additionally, we analyze key scientific and manufacturing challenges, particularly emerging directions toward high-mass-loading electrodes and next-generation flexible supercapacitors. By presenting a unified roadmap, this review aims to advance sustainable, high-energy carbon-based supercapacitor technologies and serves as a valuable reference for researchers entering the field.
Chettiannan et al. (Wed,) studied this question.