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

© 2023 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0
Interfacial engineering of two-dimensional (2D) monometallic phosphides enables remarkable structural and electrochemical properties in energy storage devices. Herein, 2D nanosheets (NSs) of FeP2/Co2P 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 developed 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 maximum 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 electroactive 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 energy (Es) and specific power (Ps) 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.
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