Remote Keyless Entry Systems a Possible App for Special Battery Chemistry

May 4, 2014

Patrick Ponticel

ORNL researchers challenged a long-held assumption that a battery’s three main components—positive cathode, negative anode, ion-conducting electrolyte—can play only one role in the device.

A new electrolyte developed the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) serves not only as an ion conductor, but also as a cathode supplement in batteries. Potential uses of the technology include remote keyless entry systems, cardiac pacemakers, sensors, and other applications "where replacing or recharging a battery is not possible or desirable." The ORNL team demonstrated the new concept in a lithium carbon fluoride battery, considered one of the best single-use batteries because of its high energy density, stability, and long shelf life. When researchers incorporated a solid lithium thiophosphate electrolyte, the battery generated a 26% higher capacity than what would be its theoretical maximum if each component acted independently. The increase is caused by the cooperative interactions between the electrolyte and cathode. As the battery discharges, it generates a lithium fluoride salt that further catalyzes the electrochemical activity of the electrolyte. This relationship converts the electrolyte—conventionally an inactive component in capacity—to an active one. The researchers say the improvement in capacity could translate into years or even decades of extra life, depending on how the battery is engineered and used.