Gas physisorption results showed that HTC-600, HTC-650, and HTC-700 have similar BET surface areas of 1411, 1245, and 1581 m 2 g -1 , respectively, and similar pore size distributions (Figure , Figure and Table ), with all carbons being predominantly microporous (with pores below 2 nm diameter). In contrast, the surface area of HTC-750 is noticeably larger (2689 m 2 g -1 ), with clear differences in the pore size distribution compared to the other carbons (Figure ). Additional characterisation using X-ray photoelectron spectroscopy (XPS) measurements revealed high surface oxygen content (~15-20 at. %) for all synthesised carbons (Figure and Table ), though the oxygen content did not show any apparent correlation with gravimetric capacitance (Figure ), similar to our previous findings. We also note that the oxygen content in bulk is much lower (less than 10 wt%) (Table ). While oxygen-containing functional groups can affect the point of zero charge (PZC) of the nanoporous carbons and thus influence their performance in aqueous electrolytes, 10 these effects may be less significant in the organic electrolyte (1 M NEt4BF4 /ACN) used in the current study. Additionally, the C MAS (magic angle spinning) NMR spectrum of HTC-650, the sample with the highest surface %O content, showed that the carbon atoms are predominantly sp 2 hybridised, with no clear signature of sp 3 content observed (Figure ). Overall, these results suggest that while chemical functionalities and porosity are often considered key parameters for capacitance, the enhanced capacitance observed for the low temperature carbons reported here likely arises from other factors. To study the synthesised carbons' local structural order degree, Raman spectroscopy measurements of carbon powders were carried out (Figure ). Deconvolution of the Raman spectra suggested a trend of decreasing sizes of graphene-like fragments (ID/IG intensity ratio values decreasing, Stage 2 of Ferrari and