Abstract
In this study, ultrahigh electrochemical performance for interconnected meso/macro-porous 2D C@α-Fe2O3 synthesized via sucrose-assisted microwave combustion is demonstrated. Hematite (α-Fe2O3) synthesized via the same approach gave an encouraging electrochemical performance close to its theoretical value, justifying its consideration as a potential supercapacitor electrode material; nonetheless, its specific capacitance was still low. The pore size distribution as well as the specific surface of bare α-Fe2O3 improved from 145 m2 g-1 to 297.3 m2 g-1 after it was coated with sucrose, which was endowed with ordered symmetric single-layer graphene (2D graphene). Accordingly, the optimized hematite material (2D C@α-Fe2O3) showed a specific capacitance of 1876.7 F g-1 at a current density of 1 A g-1 and capacity retention of 95.9% after 4000 cycles. Moreover, the material exhibited an ultrahigh energy density of 93.8 W h kg-1 at a power density of 150 W kg-1. The synergistic effect created by carbon-coating α-Fe2O3 resulted in modest electrochemical performance owing to extremely low charge transfer resistance at the electrode-electrolyte interface with many active sites for ionic reactions and efficient diffusion process. This 2D C@α-Fe2O3 electrode material has the capacity to develop into a cost-effective and stable electrode for future high-energy-capacity supercapacitors.
Original language | English |
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Pages (from-to) | 15751-15762 |
Number of pages | 12 |
Journal | RSC Advances |
Volume | 10 |
Issue number | 27 |
DOIs | |
State | Published - 21 Apr 2020 |