Pulse‐Plating of Mn–Cu–ZnO for Supercapacitors: A Study Based on Soft X‐ray Fluorescence and Absorption Microspectroscopy

Abstract

AbstractThis paper reports on the electrodeposition of Mn–Cu–ZnO for hybrid supercapacitors. This material exhibits a dual structure consisting of Mn‐rich highly active, but poorly electronically conducting, grains, which are locked by a Cu‐rich highly conductive network that also possesses some degree of charge‐storage capacity. This work focuses on morphological, compositional, and chemical‐state distributions with submicrometer lateral resolution. This information, which is crucial because doping distribution controls supercapacitor performance, has been obtained by combining electrochemical and in situ Raman measurements with synchrotron‐based X‐ray fluorescence and absorption microspectroscopy. Using a microfabricated thin‐layer three‐electrode microcell, we followed the morphochemical changes at different electrodeposition stages and found that pulse‐plating allows the growth of Mn‐ and Cu‐doped ZnO as self‐organized structures with a consistent spatially stable composition distribution.