A Technique for Evaluating Various Cathode Materials

Abstract

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.

An Investigation of the Discharge Characteristics of Groups VI–VIII Oxides in an Alkaline Electrolyte

“…The discharge curves were obtained by discharging these compounds at a rate of 0.005 amp/g in 480 g/1 A1C13.6H~O electrolyte. A similar relationship between the two dioxides also exists in strongly alkaline solution (13). The discharge curves for the two manganese dioxides in this acidic electrolyte are considerably flatter than those obtained for these compounds in solutions of higher pH.…”

“…Similarly, PtO.~ and PdO operate at potentials considerably below the theoretical values given by Latimer Pt(OH)~: + 2e-= Pt(OH).. + 40H-,E% = +0.1to +0.4 v [11] Pt(OH)~ + 2e-= Pt + 2OH-,E~ ----+0.15 v [12] Pd(OH)~+2e-=Pd+2OH-,E%= +0.07v [13] Figure 5 indicates that the reduction of Pro, to Pt appears to take place in two steps, whereas PdO exhibits a flat potential-time discharge curve in the alkaline electrolyte. For these oxides, electrode effl- Fig.…”

Investigation of the Electrochemical Characteristics of Organic Compounds

“…1 indicate the strong oxidizing character of the organic positive iodine compounds. The half-cell potential data were obtained by discharging these compounds at a rate of 0.005 amp/g .in 250 g MgBr~-6H20/1 electrolyte by a technique previously described (2) and used for the study of other organic oxidizing agents (3)(4)(5)(6)(7)(8).…”

“…C6H~IO + H~O -f-2e-= CoH.~I -k 2 OH- [1] C~HsIO~ + H20 -b 4e-= C~H~I + 4 OH- [2] The iodosobenzene and iodoxybenzene compounds operate initially at potentials comparable to those of organic positive N-halogen compounds and provide considerably higher electrode efficiencles (3). They differ from the latter compounds in that iodine is linked to a carbon atom rather than to a nitrogen 1Present address: Globe Battery ComDany, Division of Globe Union Inc., Milwaukee, Wisconsin.…”

“…1 and 2, along with the polarographic data of organic positive-iodine compounds in the literature (14), indicate that the reduction of iodoso and iodoxybenzene takes place according to Eq. [1] and [2].…”