Strongly coupled manganese ferrite/carbon black/polyaniline hybrid for low-cost supercapacitors with high rate capability

• Low-cost ternary MnFe2O4/carbon black/PANI hybrid was synthesized.
• The ternary hybrid maintained over 98% capacitance from 0.5 A g−1 to 40 A g−1.
• The assembled symmetric device showed good cycling stability for 100,000 cycles.
• The strongly coupled effects remarkably improved the capacitive performance.

Hybrid nanostructures with reliable electrochemical performances (e.g., high rate capability and long cycling lifetime) and low fabrication costs are attractive for extensive application for next-generation energy storage devices. Herein, based on the inexpensive commercial carbon black (CB), a ternary manganese ferrite/carbon black/polyaniline (MCBP) hybrid is designed and synthesized through a facile two-step approach. It is found that the synergistic effects in this strongly coupled ternary hybrid nanostructure can remarkably enhance the electrochemical performances, including the impressively high rate capability (∼98% capacitance retention at a current density of as high as 40 A g−1) and excellent cycling stability (∼80% capacitance retention after 10,000 cycles at 5 A g−1). A symmetric supercapacitor is fabricated using ternary MCBP hybrid, which presents excellent rate capability (over 94% capacitance retention at 10 A g−1) and long cycle life (∼75% capacitance retention after 100,000 cycles at 5 A g−1). Such a low-cost integrated ternary hybrid is a promising electrode material for commercial applications in supercapacitors.

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