Li–CO 2 batteries offer a promising avenue because they have a high energy density of 1876 kW h g –1 and can convert greenhouse gases into energy. The carbon‐based air‐breathing cathode of Li–CO 2 batteries plays a crucial role in facilitating CO 2 reduction and ensuring stable battery operation. However, despite recent advancements, the fundamental understanding and research on the intrinsic traits and electrochemical performance of these carbon host materials remain insufficient. In this article, we fabricated the electrically conducting carbon nanofibers (eC‐CNFs) via electrospinning followed by postcarbonization treatment. Furthermore, we established the correlation between structural, morphological, and electrochemical properties—modulated by the carbonization temperature—and battery performance of air‐breathing eC‐CNFs. Although the eC‐CNF1500 had the highest electrical conductivity, the eC‐CNF1100 demonstrated more stable battery cycling performance than eC‐CNF1500, suggesting a trade‐off between mechanical stability and electrical property as the carbonization temperature increases. Beyond the evaluation of Li–CO 2 battery performance, this study provides comprehensive insights into the intrinsic traits—mechanical properties and electrical conductivity—of eC‐CNFs tuned by the carbonization temperature.