Batteries and supercapacitors: An analytical perspective on electrode materials and performance challenges

Energy storage devices, especially batteries and supercapacitors, are essential components in portable electronics and electric vehicles, and their role in supporting renewable energy systems is becoming increasingly critical. This review investigates their principles, types, and performance challenges, with a particular focus on energy density, power density, charge/discharge rates, and cycle life. While lithium-ion batteries are widely used for their high energy density, they face significant challenges such as long charging times, high costs, and safety concerns. Consequently, alternative battery technologies, including lithium-sulfur, lithium-air, sodium-ion, and zinc-based systems, are under active investigation. Supercapacitors, known for their rapid charge/discharge cycles and high power density, are limited by their low energy density. A key area of ongoing research is the optimization of electrode materials, such as carbon-based compounds, metal oxides, and conductive polymers, to enhance the performance of both batteries and supercapacitors. This work discusses the mechanisms of energy storage, electrode degradation, and electrolyte stability, while offering insights into future developments. It underscores the importance of distinguishing between the performance characteristics of batteries and supercapacitors to avoid misconceptions, as each technology operates on distinct principles that affect their efficiency and applications. © 2025 Elsevier B.V.