Waste-to-carbon-based supercapacitors for renewable energy storage: progress and future perspectives

Materials for Renewable and Sustainable Energy https://doi.org/10.1007/s40243-024-00285-4 (2025) 14:8 REVIEW PAPER Waste‑to‑carbon‑based supercapacitors for renewable energy storage: progress and future perspectives Perseverance Dzikunu1,2 · Eugene Sefa Appiah1,2 · Emmanuel Kwesi Arthur1 · Samuel Olukayode Akinwamide2,3 Emmanuel Gikunoo1 · Eric A. K. Fangnon2 · Kwadwo Mensah‑Darkwa1,4 · Anthony Andrews1 · Pedro Vilaça2 · Received: 10 July 2024 / Accepted: 4 December 2024 © The Author(s) 2025 Abstract The increasing demand for cost-effective materials for energy storage devices has prompted investigations into diverse waste derived electrode materials for supercapacitors (SCs) application. This review examines advancements in converting waste into carbon-based SCs for renewable energy storage. In this context, different carbon-based waste precursor sources have been explored over the years as electrodes in SCs. These waste sources comprise of industrial, plastics and biowastes, including plant and animal wastes. The energy storage capabilities of the various waste derived SCs electrodes are highlighted to provide an understanding into the unique features that make them applicable to SCs. In addition, some challenges associated with the waste-derived SCs electrodes in terms of energy storage have been emphasized. Here, we also provided insights into the recent progress in SCs electrode synthesis techniques and their effects on electrochemical performance. SCs performance tailoring with material structures through the incorporation of different materials to form composites and optimized synthesis methods is an effective strategy. Hence, the synthesis methods outlined include pyrolysis, hydrothermal, microwave-assisted, template-assisted, and sol–gel techniques. The effect of the various synthesis methods on SCs performance has also been discussed. Overall, this review highlights waste valorization with future research directions and scaling challenges. Keywords Waste-to-energy · Renewable energy storage · Supercapacitors · Carbon-based electrode · Plastic waste · Biowaste Introduction * Perseverance Dzikunu * Samuel Olukayode Akinwamide 1 Department of Materials Engineering, College of Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana 2 Department of Mechanical Engineering, Aalto University, Espoo, Finland 3 Centre for Nanoengineering and Advanced Materials, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, Johannesburg, South Africa 4 Brew‑Hammond Energy Centre, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana Advancements in technology have been able to solve almost every problem in the human arena. However, one major issue associated with increasing technological advancement is the generation of tonnes of wastes that exceeds the capacity of the environment due to the ever-increasing demand for production [1–3]. The constant growth in population makes the demand for products that complement our day-to-day wellbeing skyrocket each day. Although most industries generate colossal amounts of waste annually, a significant portions are treated before disposal [4, 5]. For instance, most industries generate wastes in either solid or liquid form depending on the purpose they serve [1, 6, 7]. Besides industries, anthropogenic factors also generate a variety of wastes, such as biowastes, which are plant [8, 9] and animal [10] based wastes. The environment has combated plastic waste pollution for many decades due to the widespread single-use of plastics [11]. The predominant plastic waste is polyethylene Vol.:(0123456789) 8 Page 2 of 45 terephthalate (PET) because of its high demand for beverage and food packaging [12, 13]. Subsequently, the environment cannot decompose the various sources of waste at the same rate. This suggests the urgent need to process, recover, or convert waste into useful applications. In terms of waste decomposition, most developing countries resort to open fire burning as the main solution to minimize the waste generated in the environment [11, 14]. This leads to the release of harmful greenhouse gases into the environment, especially when plastics are involved [15]. Biowastes (plant/animalbased) although do not contain detrimental substances can still contribute to excessive generation of greenhouse gases during decomposition or burning. Recent evidence [16] suggests that most researchers are finding alternative commercial, municipal, and industrial waste uses. A typical scenario is the conversion of wastes into energy storage materials as reported in the literature [17, 18]. These wastes are usually transformed into porous carbon for several energy storage applications. Carbon is an electrode material in most energy storage systems, including SCs and batteries. This property has increased the demand for carbon sources to supplement the fossil fuel reserves that are gradually declining [19–21]. Several advanced techniques have been developed to convert wastes into highly porous carbon for energy storage applications [22, 23]. Among the carbon derivatives from wastes, activated carbon has been reported to be one of the most economical and easy to produce [24, 25]. Recent studies [26–28] have shown that utilization of waste derived carbon can effectively tackle waste management problems in the environment. The composition of industrial [29, 30], plastic [26, 31, 32], and biowastes [33, 34] makes them a viable option for synthesizing carbon with excellent properties for energy storage applications. The synthesis techniques such as pyrolysis [35, 36], hydrothermal carbonization [37, 38], sol–gel method [39, 40], and microwave-assisted approach [41, 42] can be used to convert waste into useful carbon. Due to the sustainable development drive, renewable resources for energy creation has been reported by most researchers [43, 44]. Renewable energies are always in abundance compared to fossil fuel reserves which are gradually declining [21]. However, renewable energies face the challenges of intermittency and interruption, therefore needs to be stored. The storage of these energies require devices such as batteries [45, 46] and SCs [44, 47]. These energy storage systems have been used in several applications including electric vehicles, hybrid electric vehicles, solid state drives, uninterruptible power supply, and smart systems. In addition, SCs are preferred to other energy storage because they store energy at extremely low voltages and currents. For the past decade, SCs studies have been dedicated to improving energy density by optimising electrode properties such as microstructure, porosity, and electrical conductivity Materials for Renewable and Sustainable Energy (2025) 14:8 [48, 49]. Several electrode materials, including carbon with its derivatives, metal oxides [50], and conducting polymers [51] have been used in SCs but to reduce production co (...truncated)