Energy storage for power applications: Volumetric comparison of commercial 18650 storage technologies

This paper presents an experimentally grounded volumetric benchmark of selected commercial energy-storage devices in, or close to, the standard 18650 format. The investigated set includes commercially available Lithium-Ion batteries (LIB), Sodium-Ion batteries (SIB), Hybrid Supercapacitors (HSC), and Electric Double-Layer Capacitors (EDLC), selected to represent different regions of the power–energy spectrum. By applying common experimental procedures, the study identifies the device-level strengths and limitations of these representative 18650-format implementations and provides a directly measured cross-technology benchmark. The experimental campaign combines electrochemical impedance spectroscopy across a wide temperature range with high-rate cycling to assess dynamic performance and thermal stability. Within the investigated devices and test conditions, no single solution is superior across all metrics; rather, the tested devices exhibit distinct trade-offs that are relevant to different application requirements. To support transparency and reproducibility, the complete dataset is available Open Access on IEEE Data Port at doi:10.21227/j87p-7n21 .