Iron oxides are promising materials for application in supercapacitors owing to their high theoretical redox capacitance (2299 F g À1 ). Nevertheless, iron oxide nanostructures experience constant stress during cycling due to repeated expansion and contraction resulting in structural degradation. Such structural instability makes it challenging to develop freestanding and binderfree iron oxide-based electrodes with superior electrochemical performance. In this work, the authors report a facile way to fabricate iron-based carbon nanofibers using a simple and fast technique of electrospinning followed by an in situ electrochemical conversion. The final composite electrode consists of iron oxide embedded in carbon nanofibers which possesses a robust contact and support in addition to freestanding and binder-free nature. The electrodes exhibit a capacitance of 460 F g À1 at a galvanostatic discharge current density of 1 A g À1 and retains $82% of its capacitance after 5000 cycles in a wide negative potential window of 1.3 V. Extensive spectroscopic investigation is conducted to monitor phase transformation of the electrodes during oxidation and reduction to provide a understanding of the redox mechanism during electrochemical cycling.