Mixed-phase composites derived from cobalt terephthalate as efficient battery-type electrodes for high-performance supercapattery

摘要

Interfacial engineering of two-dimensional(2D)monometallic phosphides enables remarkable structural and electrochemical properties in energy storage devices.Herein,2D nanosheets(NSs)of FeP_(2)/Co_(2) P were grown on Ni-foam(FCP)using a solution-based and phosphorization approach to be used as freestanding for high-performance energy storage devices.An effective phosphorization strategy is successfully de-veloped to improve the overall crystalline phase,tailor the morphology,and boost the electrochemical performances of electrodes.The FCP NSs electrode exhibits a battery-type redox behavior with a maxi-mum high areal capacity of 1.96 C cm^(-2) at 4 mA cm^(-2) in 6 M KOH aqueous electrolyte compared to the other counterparts.The superior electrochemical performance was achieved by increasing the electroac-tive sites and high conductivity via surface tailoring and fast redox reactions.Moreover,a supercapattery was assembled utilizing FCP and activated carbon(AC)electrodes and it revealed maximum specific en-ergy(E_(s))and specific power(P_(s))of 41.2 Wh kg^(-1) and 7578 W kg^(-1) with good cycling stability of 91%after 10,000 cycles at 5 A g^(-1).Eventually,the supercapattery has been explored in practical applications by lighting up light-emitting diodes(LEDs),representing the real-time performance of superior energy storage devices.