An Electrochemical Evaluation of Manganese Dioxide for Dry Battery Use

An apparatus and technique are described which enables a quick preliminary evaluation to be made of various manganese dioxides and other cathode materials in various electrolytes. Data are presented which show that the capacity of the manganese dioxide electrode exceeds that calculated for its reduction to Mn203.H20 when discharged at low current drains or with a flow of electrolyte over the electrode. It is also shown that the structure of the manganese dioxide material is an important property which detel~nines the performance that is obtained when the electrode is discharged, not only in a NH4C1-ZnCI: type of electrolyte, but also in a basic electrolyte.

Section: Capacity Studiessupporting

confidence: 90%

A Technique for Evaluating Various Cathode Materials

Morehouse¹,

Glicksman²

1956

“…ZnO-Mn~O3 -F 2H~O [3 ] Some years ago, it became increasingly clear that chemical reactions [2] and [3] were sufficiently slow to limit seriously the output of the Leelanch~ cell on many of the shorter time tests and heavy drain applications. A concerted study of the conditions governing the chemical or recuperation reactions was, therefore, undertaken.…”

Section: Discussionmentioning

confidence: 99%

The Influence of the Active Surface on the Cathodic Reduction of MnO[sub 2]

Cahoon¹,

Korver²

1962

Self Cite

The surface area of samples of manganese dioxide is shown to be an important factor in influencing its behavior. Four samples of MnO~ of widely different origins, electrolytic, activated, natural ore, and synthetic pyrolusite, with total surface area values of 52.8, 50.5, 7.4, and 1.6 mS/g, respectively, are used as examples. The rates of the recuperation reaction at temperatures of 21~ 50~ are shown to be related to the total surface area of the oxides by a complex relation, dependent on temperature and other factors. The product of the reaction MnOOH develops on the surface and in the pores of the original MnO~ particle, thus increasing the diameter and resulting in reduced pore volume, respectively. The MnOOH made under these conditions, from all four starting materials, appears as rod-shaped units in electron micrographs.

“…In addition to these solid products, soluble manganese has been found in the electrolyte of a discharged cathode (3). It is the purpose of this paper to extend the co-ordination of part of these findings already presented (4) to include all the above reaction products and to offer a rational theory of the cathodic reaction process.…”

mentioning

confidence: 81%

Cathode Reactions in the Leclanche Dry Cell

Cahoon¹,

Johnson²,

Korver³

1958

Self Cite

The reactions at the cathode of the Leclanch~-type dry cell are considered in terms of three heterogeneous chemical reactions for which there is advanced a plausible mechanism, leading to a unified theory of the cathode process. When reviewed in terms of this theory, the numerous observations of others that formerly have appeared to be incongruous are correlated and rationalized in terms of the over-all cathode reaction.