But the fact that the silicon layer is very thin makes it more durable than thicker silicon. In thick silicon, the holes that lithium ions leave behind can come together to form large cavities. "In the current design, because the silicon is so thin, you don't get bigger cavities, just like little gas bubbles in shallow water come up to the surface. If the water is deep, the bubbles come together and form bigger bubbles."
In future work, researchers hope to explore the thickness of the silicon layer and how well it bonds with the underlying carbon to optimize the performance and lifetime of the electrodes.
|Contact: Mary Beckman|
DOE/Pacific Northwest National Laboratory