A scaling law to determine phase morphologies during ion intercalation. Issue 7 (4th June 2020)

• Record Type: Journal Article
• Authors: Fraggedakis, Dimitrios; Nadkarni, Neel; Gao, Tao; Zhou, Tingtao; Zhang, Yirui; Han, Yu; Stephens, Ryan M.; Shao-Horn, Yang; Bazant, Martin Z.
• Is Part Of: Energy & environmental science. Volume 13:Issue 7(2020)
• Page Start: 2142
• Page End: 2152
• Publication Date: 2020-06-04
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/d0ee00653j
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : A scaling law, based on the coarsening of the slowest phase, determines the morphologies of phase separating intercalation materials. Abstract : Driven phase separation in ion intercalation materials is known to result in different non-equilibrium phase morphologies, such as intercalation waves and shrinking-core structures, but the mechanisms of pattern selection are poorly understood. Here, based on the idea that the coarsening of the slowest phase is the rate limiting step, we introduce a scaling law that quantifies the transition from quasi-equilibrium intercalation-wave to diffusion-limited shrinking-core behavior. The scaling law is validated by phase-field simulations of single Li x CoO2 particles, in situ optical imaging of single Li x C6 particles undergoing transitions between stage 1 ( x = 1) and 2 ( x = 0.5) at different rates, and all the available literature data for single-particle imaging of Li x CoO2, Li x C6 and Li x FePO4 . The results are summarized in operational phase diagrams to guide simulations, experiments, and engineering applications of phase-separating active materials. Implications for Li-ion battery performance and degradation are discussed.