Transition Metal Fluoride Cathodes for Lithium Thermal Batteries

A research and development program is being conducted at the Saft Advanced Technologies Division in Hunt Valley, Maryland, to double the energy density of a thermal battery. A baseline battery has been developed with lithium/iron disulfide chemistry to meet a set of military requirements. A study of transition metal fluoride cathodes to replace iron disulfide is in progress for an improved battery. Development of a lithium/copper(II) fluoride (CUF₂) couple is proceeding by iterative testing of single cells.

LiAl/CuF₂ cells have produced 227 Wh/kg. This exceeds the specific energy of state-of-the-art cells with iron disulfide by nearly 40%. The copper fluoride cells average 2.44 volts when discharged at a current density of 200 mA/cm².