Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6662935 | Journal of Electroanalytical Chemistry | 2013 | 9 Pages |
Abstract
Poorly crystalline porous δ-MnO2 is synthesized by hydrothermal route from a neutral aqueous solution of KMnO4 at 180 °C and the reaction time of 24 h. The as-synthesized sample and also the sample heated at 300 °C have nanopetals morphology with large surface area. On heating at temperatures ⩾400 °C, there is a decrease in BET surface area and also a change in morphology from nanopetals to clusters of nanorods. Furthermore, the poorly crystalline δ-MnO2 converts into well crystalline α-MnO2 phase. The electrochemical lithium intercalation and de-intercalation studies in a non-aqueous electrolyte provide a high discharge specific capacity (275 mAh gâ1) at a specific current of 40 mA gâ1 for the poorly crystalline δ-MnO2 samples. The rate capability is also high. There is a decrease in capacity on repeated charge-discharge cycling. The specific capacity values of the crystalline α-MnO2 samples are considerably less than the values of poorly crystalline δ-MnO2 samples. Thus, the hydrothermal route facilitates preparation of poorly crystalline electrochemically active porous MnO2.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Prasant Kumar Nayak, Tirupathi Rao Penki, N. Munichandraiah,