Rational design of sucrose-derived graphitic carbon coated MnMoO4 for high performance asymmetric supercapacitor

Abstract

The utilization of rich chemistry originating from redox activity of manganese-based compounds has spurred an increasing interest into energy storage technologies including supercapacitors and rechargeable batteries. En-gineering manganese molybdate would offer peculiar electronic properties, significantly amplify intrinsic elec-trochemical properties. Herein, graphitic carbon layers successfully coated around MnMoO4 via one-pot hydrothermal approach to form crystalline microcube-shaped structure embedded carbon matrix (su-GC@MnMoO4). Electrochemical measurements reveal, su-GC@MnMoO4 electrode demonstrated specific capacitance of 528 F g- 1 at 2 A g- 1 and a cycling retention of 98.7 % of initial capacitance after 5000 cycles. In a two-electrode system of asymmetric supercapacitor with su-GC@MnMoO4 as cathode and activated carbon (AC) as anode, we achieved specific energy of 35.4 W h kg-1 at specific power of 223 W kg-1 and 96.7 % of initial capacitance was retained after consecutive 10,000 cycles. These profound capacitive properties are ascribed to synergy between Mn redox strength and electronic-mechanical properties of sucrose derived carbon.