Power sources: Superbatteries: A progress report: Developers are banking on new materials to drive batteries into a competitive position vis-a-vis oil, gas, and gasoline

Developers of superbatteries of the future are aiming at a substantial increase in energy density-up to four times the energy per unit weight of the well-established, rugged, and reliable lead-acid battery. And the improvement is to be accompanied by reduced costs, while the lead-acid´s long life and efficiency are retained. The energy density in present batteries limits the range of electric vehicles, and for electric power utility use, the price is about double the `breakeven´ figure. Battery developers are approaching these problems by using active materials of light weight and low cost. (The active material takes or releases electrons in the electrochemical reaction.) An excellent example is the use of sodium as the negative electrode material and sulfur as the positive electrode material in a sodium-sulfur battery. Another example is the use of zinc and chlorine in the zinc-chlorine battery. These materials are readily available and cheap.