New anions as supporting electrolytes for rechargeable lithium batteries

Each of the two most commonly used salts in ambient-temperature rechargeable lithium batteries has problems involving safety and long-term stability. For example, solutions of LiClO₄ in 1,3-dioxolane are shock sensitive while LiAsF ₆/ether electrolytes degrade (both thermochemically and electrochemically) with time. Studies have been undertaken on the solubility, conductivity, and stability towards lithium of seven new lithium salts in both tetrahydrofuran (THF) and sulfolane. Of the seven salts, LiTaF₆, Li₂C₂F₄(SO₃)₂ and Li₂C₄F₈ (SO₃)₂ provide reasonable conductivities and good stability in sulfolane at 70 °C.