Efficient coupling of MnO/TiN on carbon cloth positive electrode and FeO/TiN on carbon cloth negative electrode for flexible ultra-fast hybrid supercapacitors

• Published in: RSC advances 2021-11, Vol.11 (57), p.35726-35736
• Main Authors: Li, Mai, Zhu, Kailan, Meng, Zheyi, Hu, Ruihua, Wang, Jiale, Wang, Chunrui, Chu, Paul K
• Format: Article
• ISSN: 2046-2069
• DOI: 10.1039/d1ra05742a

Recent research and development of energy storage devices has focused on new electrode materials because of the critical effects on the electrochemical properties of supercapacitors. In particular, MnO 2 and Fe 2 O 3 have drawn extensive attention because of their low cost, high theoretical specific capacity, environmental friendliness, and natural abundance. In this study, MnO 2 ultrathin nanosheet arrays and Fe 2 O 3 nanoparticles are fabricated on TiN nanowires to produce binder-free core-shell positive and negative electrodes for a flexible and ultra-fast hybrid supercapacitor. The MnO 2 /TiN/CC electrode shows larger pseudocapacitance contributions than MnO 2 /CC. For example, at a scanning rate of 2 mV s −1 , the pseudocapacitance contribution of MnO 2 /TiN/CC is 87.81% which is nearly 25% bigger than that of MnO 2 /CC (71.26%). The supercapacitor can withstand a high scanning rate of 5000 mV s −1 in the 2 V window and exhibits a maximum energy density of 71.19 W h kg −1 at a power density of 499.79 W kg −1 . Even at 5999.99 W kg −1 , it still shows an energy density of 31.3 W h kg −1 and after 10 000 cycles, the device retains 81.16% of the initial specific capacitance. The activation mechanism is explored and explained. MnO 2 ultrathin nanosheet arrays and Fe 2 O 3 nanoparticles are fabricated on carbon based TiN nanowires to produce binder-free and core-shell positive and negative electrodes for a flexible and ultra-fast hybrid supercapacitor.