Potentiostatic studies of Li(B) anodes in molten at 300°C indicate that at 80% peak open‐circuit voltage, a broad flat discharge at 780 mA cm−2 is obtained. Galvanostatic discharge studies show stable anode potentials more negative than −3V (vs. Ag+/Ag) in at 300 mA cm−2 over a temperature range of 270°–350°C. At temperatures above 350°C, deflagrations of the anode were often observed, particularly after deep discharge. Electrolyte composition is a key factor in determining the current density‐potential and potential‐temperature characteristics of the Li(B) anode in molten nitrates. Experiments in equimolar exhibit open‐circuit anode potentials up to 0.2V less electronegative to that seen in equimolar electrolyte. In a like fashion at 300 mA cm−2 and 300°C, the use of equimolar electrolyte results in Li(B) anode potentials up to 0.45V more positive than those seen in equilmolar electrolyte and up to 0.85V more positive than that seen in electrolyte. Single cell tests integrating the Li(B) anode with existing silver ion cathode technology exhibit stable cell potentials in excess of 3V at 300 mA cm−2 at 300°C. The two phase composition of the Li(B) alloy allows for exceptional anode stability at the high anode potential of elemental lithium.