Lithium-Assisted Electrochemical Welding in Silicon Nanowire Battery Electrodes
Nano Letters , 12, 1392-1397 (2012). DOI:10.1021/nl204063u
Nano Letters , 12, 1392-1397 (2012). DOI:10.1021/nl204063u
Xiao Hua Liu and Jian Yu Huang, Energy Environ. Sci., 2011, DOI: 10.1039/C1EE01918J
Our GM/UM Advanced Battery Coalition at the department of Mechanical Engineering, University of Michigan is recruiting highly motivated and independent postdoctoral researchers to study in the general field of advanced Li-ion batteries and their fading mechanisms. The candidate should hold a doctor degree in Mechanics, Materials, Chemistry, Physics, or a relevant discipline. Past experience with finite element analysis, atomistic simulations, and programming is preferred.
Silicon can host a large amount of lithium, making it a promising electrode for high-capacity lithium-ion batteries. Recent experiments indicate that silicon experiences large plastic deformation upon Li absorption, which can significantly decrease the stresses induced by lithiation and thus mitigate fracture failure of electrodes. These issues become especially relevant in nanostructured electrodes with confined geometries.
Silicon can host a large amount of lithium, making it a promising electrode for high-capacity lithium-ion batteries. Upon absorbing lithium, silicon swells several times its volume; the deformation often induces large stresses and pulverizes silicon.
During charging or discharging of a lithium-ion battery, lithium is extracted from one electrode and inserted into the other. This extraction-insertion reaction causes the electrodes to deform. An electrode is often composed of small active particles in a matrix. If the battery is charged at a rate faster than lithium can homogenize in an active particle by diffusion, the inhomogeneous distribution of lithium results in stresses that may cause the particle to fracture. The distributions of lithium and stress in a LiCoO2 particle are calculated. The e
In a lithium-ion battery, both electrodes are atomic frameworks that host mobile lithium ions. When the battery is being charged or discharged, lithium ions diffuse from one electrode to the other. Such an insertion reaction deforms the electrodes, and may cause the electrodes to crack. This paper uses fracture mechanics to determine the critical conditions to avert cracking. The method is applied to cracks induced by the mismatch between phases in crystalline particles of LiFePO4