CNT/High Mass Loading MnO₂/Graphene-Grafted Carbon Cloth Electrodes for High-Energy Asymmetric Supercapacitors.

ABSTRACT: Flexible 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.

SUBMITTER: Lyu L 

PROVIDER: S-EPMC7770775 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature