Incorporation of Impurity Metal Ions in Electrolytic Manganese Dioxide

Abstract

The amounts of impurity metal ions incorporated into electrolytic manganese dioxide (EMD) during its preparation were measured as a function of metal ion concentrations and current densities. The amount of incorporated ions increased in proportion to the concentration in solution and at a fixed concentration it was different from ion to ion: Ni 2. < Zn 2. < Co 2. < Cu z* < Fe 3. < Pb 2+. The specific surface area of the formed EMD was larger for impurity ions with higher incorporation affinity. Further, the adsorption of ions on the surface of a ready-made manganese dioxide sample (IC12) was examined, and modeling of the adsorption behavior was attempted. The amounts of adsorbed ions at a fixed concentration in solution and pH 0.7 (where EMD is produced) were obtained by the ion-adsorption model. There was a strong correlation between the amount incorporated and the amount of adsorption, suggesting a mechanism in which EMD is eontaminated through adsorption on its new growing surface. The increase in specific surface area of EMD with contaminants was interpreted to be due to a suppression of the growth of EMD at the adsorbed foreign ion sites, resulting in EMD with many defects or smaller particle sizes. The opposite effect of current density on incorporation for the two groups of metal ions was discussed.

Electrodeposition of Pluronic F127 assisted rod-like EMD/carbon arrays for efficient energy storage

“…Today it is used in alkaline primary and secondary batteries. The reversibility of this cell as being a major bottleneck, most of the Zn-MnO 2 work has focused on incorporating metal oxides additives to manganese dioxide in order to make this cell rechargeable [12][13][14][15][16][17][18][19]. EMD is one of the widely used cathode materials for alkaline batteries, lithium manganese primary batteries.…”

Manganese dioxide electrodeposition in sulphate electrolytes: the influence of ferrous ions

“…As was commented upon previously, when there is no convection reaction (8) between MnOOH and Fe 2þ ions may be predominant. However, the fact that the decrease of current in Fig.…”

“…Paul and Cartwright [7] analysed the deposition of MnO 2 in a disk and ring system in the presence of ferrous ions, and they found that the deposit can be corroded by reduction with ferrous ions at electrode potentials that seem sufficiently positive to protect the manganese oxide deposit anodically. Tamura et al [8] have studied the incorporation of metallic ion impurities, and have found that Fe 3þ ions are incorporated into the crystalline structure of the EMD, and the resulting material presents good behaviour during discharge. Elsherief [9] discussed some aspects of electroleaching of MnO 2 ore with sulphuric acid and found that the presence of ferrous ion greatly increased the speed of the reaction.…”

Electrodeposition of Sea Urchin and Cauliflower‐like Nickel‐/Cobalt‐Doped Manganese Dioxide Hierarchical Nanostructures with Improved Energy‐Storage Behavior

“…These factors resulted in a larger surface area with a porous nature, as discussed in Section 2.1. For the chosen bivalent Ni 2+ or Co 2+ dopants, the effect of nucleation rate promotes the adsorption of these ions, owing to their activity in adsorption . Together, the doped EMD materials have been successfully electrodeposited with improved physicochemical characteristics from the smaller particle sizes that enable their use as electrodes in rechargeable alkaline batteries.…”