PUB-2016-DCS

Direct Chemical Synthesis of MnO2 Nanowhiskers on Transition-Metal Carbide Surfaces for Supercapacitor Applications

Raghavan Baby Rakhi, Bilal Ahmed, Dalaver H Anjum, Husam N Alshareef "Direct Chemical Synthesis of MnO2 Nanowhiskers on Transition-Metal Carbide Surfaces for Supercapacitor Applications"
​ACS Appl. Mater. Interfaces, 2016, 8 (29), pp 18806–18814​
Raghavan Baby Rakhi, Bilal Ahmed, Dalaver H Anjum, Husam N Alshareef
cycle life; MXene; specific capacitance; symmetric supercapacitor; ε-MnO2/MXene
2016
Transition-metal carbides (MXenes) are an emerging class of two-dimensional materials with promising electrochemical energy storage performance. Herein, for the first time, by direct chemical synthesis, nanocrystalline ε-MnO2 whiskers were formed on MXene nanosheet surfaces (ε-MnO2/Ti2CTx and ε-MnO2/Ti3C2Tx) to make nanocomposite electrodes for aqueous pseudocapacitors. The ε-MnO2 nanowhiskers increase the surface area of the composite electrode and enhance the specific capacitance by nearly 3 orders of magnitude compared to that of pure MXene-based symmetric supercapacitors. Combined with enhanced pseudocapacitance, the fabricated ε-MnO2/MXene supercapacitors exhibited excellent cycling stability with ∼88% of the initial specific capacitance retained after 10000 cycles which is much higher than pure ε-MnO2-based supercapacitors (∼74%). The proposed electrode structure capitalizes on the high specific capacitance of MnO2 and the ability of MXenes to improve conductivity and cycling stability.