Assessing the Effect of Stabilization and Carbonization Temperatures on Electrochemical Performance of Electrospun Carbon Nanofibers from Polyacrylonitrile

Supercapacitors (SCs) are considered a promising alternative to batteries to power up portable and wearable devices. Among different categories of materials for SCs, carbon nanofibers (CNFs) are particularly appealing for their electrochemical, morphological, and mechanical properties, coupled with the ease of synthesis. Electrospinning is a simple and low‐cost technique to prepare the polymer‐based precursors for CNFs, allowing to obtain fibers with a tunable morphology and a diameter in the nanometer range. However, even if electrospun CNFs were intensely studied over the years, in the literature there is a lack of information regarding the optimization of the thermal treatment to prepare bare CNFs with high specific capacitance (C _s). Herein, a systematic study on the optimization of the stabilization and carbonization temperatures for electrospun CNFs prepared from polyacrylonirtile is reported, achieving a maximum C _s of 49 F g⁻¹ at 0.5 A g⁻¹ in a symmetrical SC device based on 1 

H₂SO₄ electrolyte. Aspects related to the specific surface area, nitrogen doping, and carbon microstructure are examined concerning the different thermal treatments, allowing to define structure–property–function relationships in these capacitive nanoarchitectures.