Support Effect on the Structure and Properties of Manganese Oxide Electrode Materials

Abstract

The composite electrode material of manganese oxide supported on poly glucose (PGS) was prepared by using KMnO 4 as manganese source. In order to study the influence of the support on the structure and properties of the composite electrode materials, the changes of the composition of the composite electrode materials were investigated in different weight ratio of KMnO 4 /PGS (3:1, 3:3, 3:5, 3:7, 3:9). The characterization results of XRD, Raman special and XPS indicated the composition of manganese oxides was greatly influenced by the content of PGS. When the PGS content is lower, the composition of manganese oxide in hybrid material is single-component oxide (MnOOH or Mn 3 O 4 ). With the increasing PGS content, a mixture of Mn 3 O 4 and MnCO 3 was observed, furthermore proportion of MnCO 3 in mixture also increased, and up to higher PGS content (KMnO 4 /PGS=3:9), single-component MnCO 3 was founded on hybrid material. In addition, the change of composition of hybrid materials also led to an obvious difference in electrochemical performance. With the increase of PGS content, the specific capacitance of hybrid materials increases firstly, and reaches the maximum with the weight ratio of KMnO 4 /PGS equal to 3:3, and then gradually decreases. This was attributed to the higher electrochemical performance of Mn 3 O 4 than that of MnOOH and MnCO 3 .