Highly Exfoliated 2D Nanosheets of MnO2 Assembled Alternatively with Carbon Layers for High Performance of Thick Electrode (at High Loading Mass)

초록

Owing to high theoretical capacitance and high natural abundance, manganese dioxide (MnO₂) has received great attention as a promising pseudocapacitive material. Unfortunately, the charge storage performance of MnO₂ is usually limited for commercially available mass loading electrodes because of the significant decrease of electron and ion migration kinetics in thick electrodes. Here, we report an alternatively assembled two-dimensional (2D) layered material consisting of exfoliated MnO₂ nanosheets and nitrogen-doped carbon layers for ultrahigh-mass-loading supercapacitors without sacrificing energy storage performance. A layered birnessite-type MnO₂ is efficiently exfoliated and intercalated by carbon precursor of dopamine using a fluid dynamic-induced process, resulting in interlayer-expanded MnO₂/nitrogen-doped carbon (MnO₂/C) materials after self-polymerization and carbonization. The alternatively intercalated carbon layers between MnO₂ nanosheets enable to expand interlayers of MnO₂, thus providing a fast and efficient electron and ion pathways. © 2023, The Minerals, Metals & Materials Society.

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