DISCHARGE BEHAVIOR OF COPPER(II) HALIDE CATHODES WITH MOLTEN NITRATE ELECTROLYTES

This paper describes the discharge behaviour between 150 and 220 degre es C of cells using copper(II) halide as the cathode material and molt en nitrate as the electrolyte for a reserve battery of high energy den sity running at medium temperatures. At these temperatures a lithium-a luminium alloy/copper(II) chloride cell can be discharged at a current density of 50 mA cm(-2). The open-circuit potentials are 3.45 V (agai nst 20 wt% lithium-aluminium alloy). Discharge results on the combinat ion LiAl/LiNO3-KNO3/CuCl2 cells show a capacity of 1343 C g(-1) to zer o voltage at a current density of 50 mA cm(-2) at 230 degrees C. In pr actice, this is equivalent to a specific energy output of 356 Wh kg(-1 ) of cathode to a 70% voltage cut-off. The compatibility of copper(II) chloride with nitrate electrolytes has been investigated. Copper(II) chloride appears to be compatible with nitrate up to about 260 degrees C. The performance of the LiAl/NO3/CuF2 cell was very poor giving a c apacity of 50 C g(-1).