Matt Pharr
Dept. of Materials Science & Engineering
University of Illinois at Urbana-Champaign

Lithium-Ion Batteries: Diffusion, Deformation, and Damage

Location: EB1 Room 1011

Friday, November 13th 2015 - 11:00 am

In lithium-ion batteries, electrochemical driving forces promote mass transport and stimulate chemical interactions. As atoms move and rearrange, the material deforms, thereby generating stresses. These stresses can result in fracture of the electrodes, diminishing the capacity of the battery. Meanwhile, the stresses alter the total chemical potential, and can accordingly influence mass transport and even shut off chemical reactions entirely. In this presentation, I will discuss the importance of such interplay in high-capacity lithium-ion battery electrodes. I will focus primarily on silicon anodes, which have enormous theoretical storage capacities but have achieved little success in practice due to fracture during cycling. Our theories and experiments reveal the essential conditions required to prevent fracture and thus pave the way toward realizing new high-capacity batteries.

North Carolina State University