Researchers at Oak Ridge National Laboratory (ORNL) developed an electrolyte, which has the potential to boost the energy storage capacity of lithium-ion batteries, while being safer than these on Boeing’s 787 Dreamliner.
Although the reason for the fire on the Boeing is not yet determined, if they used a safer electrolyte, the risk of fire could have been reduced dramatically. Unfortunately, there are not many options they could have picked from. Even the safest Li-ion batteries available on the market now still use flammable liquid electrolytes.
The much safer alternatives are the solid electrolytes, however it has been difficult to make them suitable for battery use.
Researchers at ORNL are in the initial stage of finding the solution. In the latest issue of the Journal of the American Chemistry Society, they published an easy method to make a nanostructured form of a solid electrolyte. This nanostructure boosts the conductivity of the materials by almost 1000 times, which makes them perfect for Li-ion batteries, and it is compatible with high-energy electrodes.
The electrolyte is very thin, which compensates for the fact that it is still not as conductive as the liquid one. This means that the batteries will not charge as fast and probably will not provide as much power, but the properties the electrolyte provides are sufficient for many applications, including electric cars.
One of the greatest advantages of the solid electrolyte is the fact that it makes the batteries much safer. Although the rates at which batteries with solid electrolytes deliver power might not be as much, the energy they provide in total will be much higher. The thin structure provides reduction in the size of batteries, saving space and weight on airplanes and electric vehicles.
Lithium-sulfur batteries might be most benefited by the new electrolyte. They store a lot of energy, but are very unsafe and cannot be recharged too many times, because they use the flammable lithium-metal electrodes. A solid electrolyte could stabilize the lithium metal, while preventing the sulfur from dissolving in the liquid.