Longevity of lithium ion batteries and their degradation kinetics are strongly dependent on the interaction of transporting Li ions with the structural defects in electrode materials. However, details of the interaction between the lithium ion flux and structural defects remain obscure due to the transient nature of such interactions. Here, by combining in situ transmission electron microscopy and density functional theory simulations, we reveal, at an atomic level, how the diffusion pathways and transport kinetics of a lithium ion can be affected by planar defects in tungsten trioxide (WO3) lattice. We discover that the changes in charge distribution and lattice spacing along the planar defects disrupt the continuity of ion conduction channels and dramatically increase the energy barrier of lithium diffusion, thus arresting migrating Li ions at the defect sites and twisting the lithiation front. The atomic-scale understanding of defects on ionic transport presented in this work holds implications for the design of rechargeable batteries and solid oxide fuel cells, and may be widely applied to similar processes during ion implantation and alloy oxidation.
Published: October 18, 2023
Citation
Liu G., Y. He, Z. Liu, H. Wan, Y. Xu, H. Deng, and J. Zhang, et al. 2023.In situ visualization of the pinning effect of planar defects on Li ion insertion.Nano Letters 23, no. 15:6839–6844.PNNL-SA-166145.doi:10.1021/acs.nanolett.3c00712