Sealed Primary Lithium-Inorganic Electrolyte Cell
Abstract
This report summarizes the R and D activities carried out by P. R. Mallory and Company on the development of a primary Li/SOCl2 D cell. The original objective of this program was to develop a D cell which is storable and operable in the temperature range of -40 to 160 F and is capable of delivering in excess of 150 WHr/lb at the thirty hour rate and peak power density of 50 watts/lb and a capacity degradation of less than 10% after one month of storage at 160 F. We showed that all the above objectives can be met by the hermetic Li/ SOCl2 D cells developed by us. However, we found that the system suffered from two inherent deficiencies: (a) A voltage delay, particularly at low temperatures after high temperature storage. (b) A chemical instability that led to an explosion hazard, particularly on shorting and forced as well as on resistive load overdischarge. We studied the voltage-delay problem in sufficient detail to define its underlying causes and developed several methods for alleviating it. Lowering the electrolyte salt (LiAlCl4) concentration as well as a partial discharge alleviated the voltage delay to an extent that the cells show no voltage delay after a storage of 1 month at 72 C and test at -30 C at currents of 0.25, 1.0 and 3.0A. We consider the problem to be essentially solved for all practical purposes. We pursued both a physical and a chemical approach to solve the explosion hazard problem. We found that low pressure venting is an effective way of preventing cell explosions on external shorts. However, this approach was ineffective in preventing explosions from forced over discharge. Also, on occasion the cells exploded on resistive load overdischarge.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1977
- Accession Number
- ADA047054
Entities
People
- A. N. Dey