Effect of bath temperature on electrochemical properties of the anodically deposited manganese dioxide

The effect of bath temperature on the electrochemical properties of electrolytic manganese dioxide (EMD) was studied. EMD was produced by anodic deposition from acidic aqueous solution of manganese sulfate at different bath temperatures in the range of 60-120 degreesC. At temperatures above the boiling point of water, the electrolysis was carried out in an autoclave. The EMD produced at 120 degreesC was of,gamma type, identified by X-ray diffraction (XRD). Furthermore, the materials produced at 115 and 120 degreesC were quality-controlled by cycling a sample as cathode mix in small size RAM-cells and by scanning electron microscopy. The results indicated an increase in cyclic charge/discharge performance and an improvement of crystallization conditions of EMD produced at elevated temperature when compared to data of commercially available gamma -MnO2. (C) 2001 Elsevier Science B.V. All rights reserved.