Solid phase modifiers of the Fe(VI) cathode: effects on the super-iron battery

Cathodes comprised of Fe( VI) salts, and capable of three-electron reduction, are useful for the formation of energetic super-iron batteries. Several solid phase modifiers can significantly impact the electrochemical characteristics of the Fe(VI) cathode. The average discharge potential of the super-iron alkaline battery may be increased by similar to 150 mV by addition of a few percent by weight of solid Co(III) salts, such as Co2O3. This potential may be decreased by similar to 200 mV, through manganate or permanganate coating of the Fe(VI) particles with small amounts (for example, 1%) of MnO2. Evidence indicates that the modifier effects are electrocatalytic in origin. The addition of In, such as In2O3, to the cathode improves (decreases) the reversible charging potential of the Fe(VI) cathode and improves the cycle life of the super-iron metal hydride battery. (C) 1999 Elsevier Science S.A. All rights reserved.