Manganese oxide (MnO2) has long been investigated as a pseudo-capacitive material for fabricating fiber-shaped supercapacitors but its poor electrical conductivity and its brittleness are clear drawbacks. Here we electrochemically insert nanostructured MnO2 domains into continuously interconnected carbon nanotube (CNT) networks, thus imparting both electrical conductivity and mechanical durability to MnO2. In particular, we synthesize a fiber-shaped coaxial electrode with a nickel fiber as the current collector (Ni/CNT/MnO2); the thickness of the CNT/MnO2 hybrid nanostructured shell is approximately 150 μm and the electrode displays specific capacitances of 231 mF cm−1. When assembling symmetric devices featuring Ni/CNT/MnO2 coaxial electrodes as cathode and anode together with a 1.0 M Na2SO4 aqueous solution as electrolyte, we find energy densities of 10.97 μWh cm−1. These values indicate that our hybrid systems have clear potential as wearable energy storage and harvesting devices.
All Science Journal Classification (ASJC) codes
- Materials Chemistry
- Environmental Chemistry