Scialog: Advanced Energy Storage - 2017
Ion REASSIN: Ion Re-Coordination at Solid-State Interfaces
The electrolyte – the part of a battery which enables electrical current by allowing ions (electrically charged particles) to move between electrodes (the anode and cathode) – is a liquid in most types of batteries, including in widely used lithium ion (Li-ion) batteries. Unfortunately, liquid electrolytes can degrade in ways that trigger fires and explosions. Solid electrolytes avoid the dangers of liquid electrolytes but don’t perform as well in other ways. So wouldn’t it be great if scientists could come up with improved solid electrolytes, offering similar or even better performance and much greater safety than liquid electrolytes?
One of the hurdles to doing so is figuring out how to create faster ion transfer at solid-solid interfaces -- that is to say, maximizing the flow of ions between the solid electrolyte and the battery’s electrodes. However, scientists have limited knowledge of how ions move and re-coordinate across such interfaces, and designing interfaces with maximized ion transfer properties, which allows for ultrafast battery charging, is a major challenge.
Veronica Augustyn, NC State, Matthew McDowell, Georgia Tech, and Aleksandra Vojvodic, U Penn, have received a Scialog award from Research Corporation for Science Advancement (RCSA) to test their hypothesis that compositionally sharp interfaces will lead to the lowest ion migration barriers, and that these kinds of interfaces can be designed and stabilized by using a single layer of atoms of a third material in between the solid electrolyte and electrodes. The single layer of atoms is referred to as two-dimensional (2D), because it is atomically thin and thus effectively lacks depth.
If they’re able to demonstrate 2D layers significantly improve ion transport at solid-solid interfaces, the researchers will have made a major contribution towards understanding the dynamics and performance of solid-state electrolytes and establishing the scientific foundation for widespread use of novel solid-state batteries.