The Cycling Behaviour of MnO2 as Investigated By Synchrotron XRD, Stepped Potential Electrochemical Spectroscopy (SPECS) and Cycling on the Electrochemical Quartz Crystal Microbalance (EQCM)
One possible problem with the long term utilisation of pseudo capacitors, such as metal oxides, is that they can undergo structural change during cycling. This presentation will cover the cycling behaviour of Birnessite, Ramsdellite and Pyrolusite as examined by a number of different techniques. SPECS experiments performed in-situ at the Australian Synchrotron to map structural changes with respect to the state of charge of a manganese oxide material. In addition, data obtained on the mass changes during SPECS cycling of the three phases on the EQCM will be presented. The mass change, when corroborated with the amount of charge passed, gives information about the type of ions being inserted into the structure. In the case of these experiments, % values of K+ and H+ insertion have been obtained. In addition, values for retention of these ions during repeated cycling have been elucidated, which will provide valuable information for researchers engaging in the intelligent design of electrochemical capacitors utilising MnO2.
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