The University of Michigan have developed a new technology that could radically improve the efficiency of lithium ion batteries without increasing battery size or weight. The university study focused on replacing the current battery electrolytes with ceramic, solid-state electrolytes.
Liquid electrolytes were very popular in the early 90’s, however had major drawbacks due to issues such as short circuiting and poor durability. This often caused ignition whilst charging and was one of the major safety concerns that surrounded the storage method. Lithium ion batteries were developed in 1991 and quickly became the new standard as these batteries replaced the lithium metal with graphite anodes, absorbing the lithium and reducing the chance of combustion. Whilst the graphite anodes have made lithium batteries safer, they have also significant reduced the storage performance as graphite can only hold one lithium ion for every six carbon atoms.
The team at UM have solved the lithium metal’s combustion issue by creating a ceramic layer that stabilises the surface. This prevents dendrites from forming, which then prevents fires from occurring.
Jeff Sakamoto, the university’s associate professor of mechanical engineering said;
“This could be a game-changer – a paradigm shift in how a battery operates”. By effectively removing the fuel from the equation, researchers have reduced the possibility of a combustion occurring, with numerous tests above 1800 degrees Fahrenheit yielding no liquid production, often the main source of ignition.
Current lithium ion batteries have a maximum of 600 watt-hours per litre, whereas the solid-state batteries can reach up to 1200 watt-hours per litre. The new technology could have a major impact on the electric vehicle industry, as target battery prices are $US100/kWh in order to commercially compete with the rest of the vehicle industry.