Three HC structures prepared at different pyrolysis temperatures that resulted in distinct microstructures were studied with ex situ X-ray pair-distribution function (XPDF) analysis to determine the average local structure and sodium storage mechanisms. Samples prepared with pyrolysis temperatures of 1100°C, 1400°C, and 2000°C were investigated, denoted here as HC-1100, HC-1400, and HC-2000, respectively. To compare between different types of HC, we define a "state of sodiation" (SoS), where 0% SoS represents pristine HC and 100% represents the capacity at C/20 with a cutoff voltage of 0 V vs Na/Na + . For the second cycle sodiation, the SoS is defined relative to the maximum capacity achieved during the first cycle sodiation. Each HC variant exhibits a unique potential-capacity curve. As depicted in Figure ), HCs prepared at lower temperatures exhibit a higher slope capacity fraction, a smaller plateau capacity fraction, and a higher potential at the plateau onset compared to HCs prepared at higher temperatures.