Large Li/CFx cell performance

Abstract

The characteristics of a family of large, high energy density lithium/carbon monofluoride primary cells are described. The family of cells ranges in size from 'C' to a 2737 cm/sup 3/ (1200 Ah) cell. Emphasis is on the 'DD' and larger cells. Construction details are presented, including the use of a unique miniature McHenry-Ziegler compression seal in place of a glassed terminal and the use of an epoxy-carbon-fiber sleeve on the largest cell to maintain high strength with low weight. Electrochemical and real time data to date indicate no corrosive attack or degradation of the compression seal, eliminating a common cell failure mechanism. Full electrical performance data is presented for the 'DD' size cell and preliminary performance data for the larger cell sizes. Specific energy in excess of 600 Wh/kg and energy density in excess of 1000 Wh/L is routinely achieved in the 'DD' size cell. Specific energy of almost 1200 Wh/L has been achieved in the as yet unoptimized 1200 Ah size cell. Response of the large cells to common physical and electrical abuse conditions is presented, including shorting, reversal, charging incineration, spiking, crushing and heating per NAVSEA 9310. The worst response noted was deflagration under the incineration, spiking and some of the crushing tests.