LAUSR

HighlightsCNT/MnO2/graphene-grafted carbon cloth electrode is designed and achieves high MnO2 mass loading (9.1 mg cm−2).The electrode with favorable electronic/ionic conductivity delivers a large areal capacitance and rate capability.The assembled asymmetric supercapacitor yields a large energy density of 10.18 mWh cm−3.AbstractFlexible supercapacitor electrodes with high mass loading are crucial for obtaining favorable electrochemical performance but still challenging due to sluggish electron and ion transport. Herein, rationally designed CNT/MnO2/graphene-grafted carbon cloth electrodes are prepared by a “graft-deposit-coat” strategy. Due to the large surface area and good conductivity, graphene grafted on carbon cloth offers additional surface areas for the uniform deposition of MnO2 (9.1 mg cm−2) and facilitates charge transfer. Meanwhile, the nanostructured MnO2 provides abundant electroactive sites and short ion transport distance, and CNT coated on MnO2 acts as interconnected conductive “highways” to accelerate the electron transport, significantly improving redox reaction kinetics. Benefiting from high mass loading of electroactive materials, favorable conductivity, and a porous structure, the electrode achieves large areal capacitances without compromising rate capability. The assembled asymmetric supercapacitor demonstrates a wide working voltage (2.2 V) and high energy density of 10.18 mWh cm−3.