Design optimisation of supercapacitor-based energy storage systems for high peak power applications

This paper presents a design methodology, cell selection criteria, and optimisation framework for supercapacitor-based energy storage systems (SC-ESS) targeting high peak power applications, such as aerospace, across wide temperature ranges. Cell modelling and experimental testing were used to evaluate candidate cells under realistic application-specific cycling conditions. Results revealed significant deviations from rated specifications when subject to the harsh conditions of the target aerospace application, particularly under low temperatures. A multi-objective optimisation, incorporating energy density, thermal stability, and ESS system weight, initially identified one low-rated cell as the most promising option. However, subsequent cycle-ageing tests showed that this cell type did not sustain capacity over the required lifetime, whereas two other electric double-layer capacitor models were able to meet the 100,000-cycle threshold with variability between units. These findings highlight the importance of integrating long-term ageing performance alongside temperature stability and energy density when selecting supercapacitor technologies for high peak power ESS design. • Datasheet-driven design of aerospace supercapacitor energy storage for peak power. • Multi-objective optimisation trades energy density, temperature limits and weight. • High-power cycle ageing performed on various Electric double-layer capacitors (EDLCs). • EDLCs hit 100,000 cycles, with unit variability.