Flexible self-powered fiber-shaped photocapacitors with ultralong cyclelife and total energy efficiency of 5.1%

Fiber-shaped photocapacitors (FPCs) combine functions of energy harvesting and storage in a single device has attracted great attention for their potential applications in portable and wearable electronics . However, the FPCs suffer from the low photochemical-electric energy conversion efficiency and poor cycling stability due to the limitation of the fiber-shaped electrodes. Herein, high crystalline conductive polymer fibers with high electrocatalytic activity and energy storage efficiency for both energy harvest and energy storage are prepared and used as shared electrode to fabricate efficient and stable FPCs. Synergistically, the FPCs fabricated by combining a fiber-shaped dye-sensitized solar cell and a fiber-shaped supercapacitor into one device by sharing one electrode exhibit a remarkable total photochemical-electric energy conversion efficiency up to 5.1%, which is higher than that of reported energy fibers and even close to those of the planar devices in previous reports. Meanwhile, the fabricated FPCs show superior cycling capability for more than 1700 photocharge/galvanostatic discharge cycles (63 days) with efficiency retention of 70.6%. The FPCs woven into the textile can steadily power the ultraviolet photodetector after photocharged in natural sunlight, showing potential in the application of wearable electronics.