A Phase I Program to the Low Temperature Performance of Li-ion Batteries

79758B Safety concerns over the susceptibility of large Li-ion cells to thermal runaway during overcharge are one of the problems preventing the commercialization of these cells. This problem will be addressed by developing new materials that will be substituted for the cell component believed to be involved in the runaway process. In particular, electrolyte systems that form less a resistive interface between the electrolyte and the electrodes will be developed. In Phase I, the new electrolyte systems will be prepared using various solvent and salt mixtures. These electrolytes will be studied by differential capacity measurements during formation, electrochemical impedance measurements, and conductivity measurements. These measurements will then be correlated to actual cell performance. Commercial Applications and other Benefits as described by the awardee: The technology should improve the performance of Li-ion batteries at low temperatures and also be cost effective. Applications include hybrid and electric automobiles as well as military and aerospace applications.