Matching CP@NCOH/NF Cathode and GH/FNP/NF Anode for High-Performance Asymmetric Supercapacitor.

Abstract

It is extremely crucial to design and match high-quality cathode and anode for achieving high-performance asymmetric supercapacitors (ASCs). Herein, Co3 (PO4 )2 @NiCo-LDH/Ni foam (CP@NCOH/NF) cathode with hierarchical morphology and graphene hydrogel/Fe-Ni phosphide/Ni foam (GH/FNP/NF) anode with the robust and porous structure are elaborately designed and prepared, respectively. Owing to their unique and profitable structures, both CP@NCOH/NF and GH/FNP/NF electrodes yield the superior capacity (10760 and 2236 mC cm-2 at 2mA cm-2 , respectively), good rate capability (63% retention at 200mA cm-2 and 52% retention at 50mA cm-2 , respectively), and excellent cycling stability (72% and 74% retention after 10000 cycles, respectively). Benefiting from their matchable electrochemical performances, the configured solid-state CP@NCOH/NF//GH/FNP/NF ASC outputs both competitive energy density (80.2Wh kg-1 /4.1 mWh cm-3 ) and power density (14563W kg-1 /750mW cm-3 ), companied by remarkable cyclability (71% retention after 10000 cycles), manifesting its great promise for large-scale integrated energy-storage system.