Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) in Tennessee say they have developed a new type of battery chemistry aimed at producing batteries that last longer than previously thought possible.
The ORNL researchers challenged a long-held assumption that a battery’s three main components (the positive cathode, negative anode, and ion-conducting electrolyte) can play only one role in the device.
The electrolyte in the team’s new battery design has dual functions. Not only does it serve as an ion conductor, but also as a cathode supplement. This delivers an extra boost to the battery’s capacity and extends the lifespan of the device.
The 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 the researchers incorporated a solid lithium thiophosphate electrolyte, the battery generated a 26 percent higher capacity than what would be its theoretical maximum if each component acted independently. The increase, they say, is caused by the cooperative interactions between the electrolyte and cathode.
The improvement in capacity could translate into years or even decades of extra life, depending on how the battery is engineered and used. Longer-lived disposable batteries are needed for artificial cardiac pacemakers, radiofrequency identification devices, remote keyless system, and sensors, where replacing or recharging a battery is not possible or desirable.