Comparative performances of some indigenous manganese dioxides in experimental dry cells

The paper describes the fabrication of dry cells with five different manganese dioxides namely N.M.L. electrolytic, synthetic (imported), West African Ore and two indigenous ores, using different amounts of Shawinigen carbon black. Light Industrial Flash Light tests and a few short circuit current capacity tests show that N.M.L. electrolytic manganese dioxide is very suitable for high drain cells. It is also shown that N.M.L. electrolytic manganese dioxide alone or in admixture with the other four dioxides gives satisfactory performance in dry cells in fresh state and after ageing for six months. (Mr. P.L. Joseph, Senior Scientific Assistant, NML, (now Scientists, Central Electro-chemical Research Institute, Karaikudi), Mr. H.K. Chakrabarti, Scientist, NML and Dr. T. Banerjee, Scientist-in-charge, NML, Jamshedpur