In recent years, interest has risen in fast-charging energy storage devices such as supercapacitors, driven by the current climate and energy crises . In the past three years alone, more than 20000 publications have been published in this area , and various approaches have been taken to attempt to improve the energy and power performances of supercapacitors. The performances of existing carbon electrode materials have been improved through heteroatom doping, compositing with pseudocapacitive materials, and by structure optimisation . Novel electrode materials with performances on-par with or exceeding carbon materials have also been developed, including MXenes, metal-organic frameworks (MOFs), and transition metal oxides (TMOs) . Further research has focussed on developing new electrolytes with higher stable voltage windows and greater ionic conductivities . While improving the performance of these devices is crucial, successfully integrating supercapacitors with other energy conversion and storage technologies, including in practical and wearable devices, is also critical for many future applications . In all these papers, performance metrics such as total capacitance, specific capacitance, and internal resistance are commonly reported by researchers . However, with more groups beginning to venture into the field and an increasing number of reported devices exhibiting non-ideal capacitive behaviour, variation in data analysis can lead to inconsistent and unreliable results being reported across different laboratories.