ABSTRACT This work explores the influence of two different fabrication strategies on the electrochemical performance of Fe doped TiO 2 nanotube electrodes for supercapacitors. Electrodes of anatase phase (TNT/Fe‐450) and mixed phases of TiO 2 (B) and brookite (TNT/Fe‐60) were prepared, respectively, by the conventional electrochemical anodization and a novel “water‐bath temperature‐controlled anodization” method, respectively. While the TNT/Fe‐450 electrode exhibited a maximum areal (gravimetric) specific capacitance of only 86.48 mF cm −2 (166.30 F g −1 ), the TNT/Fe‐60 showed nearly 10‐fold enhancement in energy storage efficiency, with a maximum specific capacitance of 952.59 mF cm −2 (1693.49 F g −1 ) from cyclic voltammetry. Galvanostatic charge discharge measurements yielded a maximum specific capacitance (Cs) of 1427.99 F g −1 , an energy density (ED) of 300 W h kg −1 and a power density (PD) of 2.43 kW kg −1 , for TNT/Fe‐60. Asymmetric supercapacitors of two configurations with TNT/Fe‐60 as the negative electrode and either activated conducting carbon cloth (ACC) or MnO 2 over CC, as the positive electrode were assembled. The MnO 2 ‐paired ASC demonstrated the best performance, with a high Cs of 352.19 Fg −1 at 10 mV s −1 , ED of 94.05 W h kg −1 , PD of 5.46 kW kg −1 , and 100% capacity retention in 5 k cycles, indicating its potential for high energy storage applications.
Nair et al. (Fri,) studied this question.