Single-fiber-based hybridization of energy converters and storage units using graphene as electrodes.

Recently, there has been great interest in wearable and stretchable energy generation and storage devices utilizing nanotechnology for applications such as self-powering nanosystem that harvests its operating energy from the environment. [ 1 ] Solar, mechanical and thermal energy can be scavenged from the environment using devices that were fabricated using fl exible or stretchable substrates. For example, textile-fi bre-based nanogenerators have been demonstrated utilizing ZnO nanowires (NWs) grown on Kevlar fi bres to scavenge low-frequency mechanical energy. [ 2 ] Twisted fi bre-like electrodes have been used for harvesting solar energy using the dye-sensitized solar cells (DSSCs) approach. [ 3 ] Once the energy is harvested from the environment, an energy storage device is required in order to maintain the operation of the system, but it is usually a separated unit from the energy converters. Flexible batteries. [ 4 ]