Synthesis, analysis, and electrochemical properties of a new lithium salt with an exceptionally large, weakly coordinating anion, lithium bis{1,2-tetra(trifluoromethyl) ethylenediolato (2-)-O,O'} borate {LiB[OC(CF3)(2)](4)}, are described. This salt, whose anion contains 24 fluorine atoms, can be fused at remarkably low temperatures (120 degrees C) and is stable up to 280 degrees C. The salt has a low conductivity in the molten state, only 7.1 x 10(-6) S cm(-1) at the melting point of 120 degrees C due to its quasi-molecular character. However, its solutions in molecular solvents are extremely conductive. The maximum conductivity of LiB[OC(CF3)(2)](4) in dimethoxyethane (DME) is 11.1 x 10(-3) S cm(-1) at 25 degrees C. The electrochemical stability for each of the DME and propylene carbonate solutions is at least 4.5 V vs. Li+/Li.