Multiwalled Carbon Nanotubes Decorated Ɛ-Mno2nanoflowers Cathode with Oxygen Defect for Aqueous Zinc-Ion Batteries

Abstract

As a potential cathode for aqueous zinc-ion batteries, the low electrical conductivity and poor electrochemical kinetics of MnO2 limit its further development and application. Herein, multiwalled carbon nanotubes decorated MnO2 nanoflowers with hexagonal structure (ɛ-MnO2/MWCNTs) were synthesized by one-step co-precipitation method. The ɛ-MnO2/MWCNTs inherit the advantages of highly conductive MWCNTs and nanostructured MnO2, thus showing excellent zinc-ion storage capacity. The ɛ-MnO2/MWCNTs display high invertible capacity of 335.6 mAh g-1 at 0.2 A g-1 after 150 cycles, and long-term capacity of 115.7 mAh g-1 at 2.0 A g-1 after 4000 cycles. The results of kinetics tests further reveal that the MWCNTs decoration can reduce polarization of MnO2 and accelerate its reaction kinetics. Thanks to these merits, the ɛ-MnO2/MWCNTs hold great potential for high performance eco-friendly batteries cathode material.

Keywords: ɛ-MnO2, MWCNTs, Oxygen defect, Cathode, Zinc-ion batteries