Vicran Zharvan, Eko Hadi Sujiono, Kuwat Triyana
Activated carbon derived from biomass has emerged as a promising electrode material for supercapacitors due to its low cost, environmental sustainability, and tunable porous structure. Among various biomass precursors, coconut shell stands out because of its high lignin content, rigid structure, and high carbon yield, which enable the formation of stable microporous carbon suitable for electrical double-layer capacitance (EDLC)-based energy storage. Extensive research has been devoted to synthesizing coconut shell–derived activated carbon using physical and chemical activation methods, particularly alkali-based activation, to enhance surface area and pore accessibility. However, reported electrochemical performance varies significantly, even for materials prepared with similar activation strategies, indicating that surface area alone cannot fully account for the charge-storage behavior.This review critically examines the relationships among activation methods, pore architecture, surface chemistry, and the electrochemical performance of coconut shell–derived activated carbon used as supercapacitor electrodes. Both non-composite activated carbon and composite-based electrodes incorporating conductive carbon or metal oxides are discussed, with non-composite systems emphasized as the fundamental baseline. Rather than providing a descriptive summary, this work evaluates structure–property–performance correlations. It highlights common misinterpretations in the literature, such as the overestimation of specific surface area as the dominant performance parameter.Importantly, this review identifies a clear research gap in the rational design of coconut shell–derived activated carbon, where pore size distribution, surface functional groups, and interfacial charge transfer are rarely optimized in a coordinated manner. The primary objective of this review is to establish a unified framework that links synthesis strategy to charge-storage mechanism, while outlining future research directions focused on controlled pore engineering, interface-tailored composite design, and device-level performance evaluation to enable the development of high-performance, scalable coconut shell–based supercapacitor electrodes. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, PO Box BLS 21, Yogyakarta, 55281, Indonesia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Makassar, Jl. Mallengkeri, Makassar, 90224, Indonesia
