Electrodes Based on Se Anchored on NiCoP and Carbon Nanofibers for Flexible Energy Storage Devices
Mohd Afshan, Sushil Kumar, Daya Rani, Mansi Pahuja, Rishita Ghosh, Shumile Ahmed Siddiqui, Sk Riyajuddin, Kaushik Ghosh
Abstract
In an energy storage device, it is indeed a necessity to develop a flexible binder-free electrode. However, the rational design of such a binder-free electrode with high energy density and long cyclic stability is a great challenge for the scientific community. Herein, Se-anchored NiCoP nanoparticles have been developed that are in situ decorated on the surface of polyacrylonitrile-based heat-treated flexible carbon nanofibers (CNFs). The as-designed electrode demonstrates a remarkable specific capacitance/capacity of 994 F g–1/497 mAh g–1 at 1 A g–1. The flexible solid-state symmetric supercapacitor (SSC) device delivers 76.86 Wh kg–1 energy density at a power density of 843.75 W kg–1 at 0.75 A g–1 and retains a promising energy density of 22.75 Wh kg–1 at an ultrahigh power density of 11250 W kg–1 at 10 A g–1, respectively. The device also shows excellent long cyclic stability in terms of 94.12% capacitive retention along with 98.65% Coulombic efficiency after 15000 cycles at an applied high current density of 10 A g–1. The synergetic effect of Se-anchored NiCoP with CNF along with the significant protection of NiCoP by a thin graphitic shell as well as suitable anchoring of electroactive materials on a CNF matrix via Se bridging may help to achieve such a high-performance energy storage device. The four sets of 1 × 1 cm2 prototype devices (connected in series) are capable of enlightening a red-light-emitting diode (2.2 V) for 8 min and rotating a 3 V electric direct-current motor for 4 min via charging through a standard Si solar panel (6 V) illuminated by a 50 W street light for 2 min. The study creates an avenue toward the realistic drive of renewable energy conversion via the development of a high-performance flexible energy storage device.