Affiliation:
1. Department of Physics Indian Institute of Technology Roorkee Roorkee 247667 Uttarakhand India
2. Department of Physics and Joint Faculty Center for Sustainable Energy Indian Institute of Technology Roorkee Roorkee 247667 Uttarakhand India
Abstract
AbstractFlexible energy storage devices are attracting a great attention nowadays in the rapidly growing area of implantable/wearable electronics. This bloom has generated great demands on flexible wire‐shaped supercapacitors (WSC) as power sources in wearable electronic systems that can offer tunable sizes, shapes, and versatile designs. Herein, a flexible WSC is fabricated using MgMn2O4 nanofibers (MMO‐NFs) over a flexible carbon yarn substrate via the electrophoretic deposition method in the first report. The binder‐free deposition of highly porous and one‐dimensionally aligned MMO‐NFs over carbon yarn offers excellent ionic/charge transport into the fabricated device. The assembled WSC device at 0.1 mA/cm current rate shows capacitances of 386 mF/cm2 and 45.5 mF/cm. A capacitance retention of 88 % for a WSC device after 10,000 cycles indicates its good cyclability. Further, the WSC exhibits good flexibility, retaining 94 % of capacitance at 0.5 mA/cm after 2000 bending cycles. Furthermore, the flexible WSC device shows power and energy density of 744 μW/cm and 14.2 μWh/cm, respectively. Additionally, WSC devices demonstrate their practical energy storage capabilities in a video that shows three similar devices being knitted into a wearable glove and glowing a red light‐emitting diode (LED) for more than five minutes in various bending positions.