English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Although manganese oxide- and graphene-based supercapacitors have been widely studied, their charge storage mechanisms are not yet fully investigated. In this work, we have studied the charge storage mechanisms of K-birnassite MnO 2  nanosheets and N-doped reduced graphene oxide aerogel (N-rGO ae ) using an  in situ  X-ray absorption spectroscopy (XAS) and an electrochemical quart crystal microbalance (EQCM). The oxidation number of Mn at the MnO 2  electrode is +3.01 at 0 V vs. SCE for the charging process and gets oxidized to +3.12 at +0.8 V vs. SCE and then reduced back to +3.01 at 0 V vs. SCE for the discharging process. The mass change of solvated ions, inserted to the layers of MnO 2  during the charging process is 7.4 μg cm −2 . Whilst, the mass change of the solvated ions at the N-rGO ae  electrode is 8.4 μg cm −2 . An asymmetric supercapacitor of MnO 2 //N-rGO ae  (CR2016) provides a maximum specific capacitance of ca. 467 F g −1  at 1 A g −1 , a maximum specific power of 39 kW kg −1  and a specific energy of 40 Wh kg −1  with a wide working potential of 1.6 V and 93.2% capacity retention after 7,500 cycles. The MnO 2 //N-rGO ae  supercapacitor may be practically used in high power and energy applications.

Charge storage mechanisms of manganese oxide nanosheets and N-doped reduced graphene oxide aerogel for high-performance asymmetric supercapacitors