Abstract by Kevin Laughlin
Physics and Astronomy
Microscale encapsulation of silicon coated CNT anodes for lithium ion batteries
Rechargeable batteries have become an integral part of everyday life with devices like cell phones and laptops, or larger objects like electric cars. While the technologies using batteries have rapidly improved, rechargeable battery capacity has not improved as quickly. This has produced powerful devices that aren’t able to last very long before needing to be recharged. The storage capacity of a rechargeable lithium ion battery could be significantly increased by using new materials.. We are currently working with silicon which has ten times the specific capacity of commercial carbon battery anodes. However, with this increased capacity comes several problems including a 300% volume expansion which can cause catastrophic mechanical failure, and a parasitic reaction with battery electrolyte. We are addressing the expansion issue by coating carbon nanotubes with thin silicon layers that experiences much less stress on expansion. The parasitic reaction may be eliminated through a new method of microencapsulation that prevents electrolyte from coming into contact with the silicon.