A review on nano-structured electrodes for high-performance supercapacitors: panoramic insights across dimensional spectra

Abstract The design architecture of electrode materials plays a pivotal role in shaping the electrochemical performance of supercapacitor. The dimensionality of electrode material proposes trade-off between specific surface area, pore architecture, mechanical strength and flexibility. This review undertakes a comprehensive classification of electrode materials into zero-dimensional, one-dimensional, two-dimensional, and three-dimensional architectures, further correlating their structural characteristics with surface area, electrical conductivity, and ion transport dynamics. Various classes of materials, including carbon-based nanostructures, transition metal oxides, transition metal dichalcogenides, MXenes, and metal–organic frameworks, are analysed with respect to morphology-dependent performance characteristics. The design of heterostructures and multi-dimensional electrodes, as well as various synthesis methods, and the crucial elements of sustainability and scalability, are also taken into account. Furthermore, viewpoints for future avenues that pave the way for the development of supercapacitors are presented. Overall, this review aims to bridge the understanding between dimensional architecture, synthesis approach and performance, offering acuity in rational material design strategies for sustainable, high-performance supercapacitor systems.