Improved Cathode Systems for High-Energy Primary Batteries.
Abstract
The improvement of cathode performance in primary organic electrolyte batteries by conversion of the active material to an electronic semiconductor was investigated in this program. A series of n-type cadmium fluoride single crystals was prepared by a two-stage high-temperature doping process. Initial efforts to prepare n-type manganous fluoride by analogous procedures did not yield a conductive material. The cadmium fluoride crystals were characterized by the measurement of bulk and contact resistivities, using indium amalgam contacts. The crystal specimens were then examined electrochemically by cathodic discharge at constant current density in a lithium perchlorate - propylene carbonate electrolyte. An electronic mechanism for the discharge of n-type cadmium fluoride was confirmed by the observation of cadmium deposition at the semiconductor/electrolyte interface. An undoped crystal was inactive when examined in the same electrode configuration. Two problems were encountered in the use of semiconducting cadmium fluoride as a cathode material: (1) passivation of the crystal surface, and (2) a requirement for careful preparation of the contact between the semiconductor and the external circuit. Recommendations for future work include investigation of the passivation process and means for its control, comparison of reaction rates for electronic and other discharge mechanisms, and continued efforts to prepare semiconducting transition metal halides. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1969
- Accession Number
- AD0861898
Entities
People
- Margie M. Nicholson