Li-ion Batteries

Our group is studying how the fundamental crystal chemistry of intercalation hosts influences the transport of ions through the solid state. We are particularly interested in polyanionic compounds, like sulfates and silicates, which contain rigid subunits consisting of strong covalent bonds between a main group element and its ligands, because of their robust structures and rich compositional phase diagrams. We have done extensive work to demonstrate that these materials exhibit significantly different structural distortions compared to traditional oxide based hosts. Whereas oxides may experience short-range structural distortions to accommodate the volumetric changes required as Li is (de)inserted into the framework, polyanionic hosts must perform cooperative rotations of the rigid subunits in order to satisfy the local bonding within the polyanionic group. This mechanism can be highly beneficial as it is a highly reversible process that maintains the integrity of the structure over thousands of cycles, yet this rigidity may also limit the directions along which ions can hop from site to site, potentially slowing their mobility.

Selected Publications

Vincent et al. High-Rate Lithium Cycling and Structure Evolution in Mo₄O₁₁ Chem. Mater. 34 (2022) 4122–4133 [doi]

Andrews et al. Impact of Structural Deformations on the Performance of Li-Ion Insertion Hosts Chem. Mater. 34 (2022) 4809–4820 [doi]

Stiles et al. Reversible Intercalation of Li Ions in an Earth-Abundant Phyllosilicate Clay Inorg. Chem. 61 (2022) 5757–5761  [doi]

Bashian et al. Transition Metal Migration Can Facilitate Ionic Diffusion in Defect Garnet Based Intercalation Electrodes ACS Energy Letters 5 (2020) 1448-1455 [doi]

Bashian et al. Correlated Polyhedral Rotations in the Absence of Polarons During
Electrochemical Insertion of Lithium in ReO3 ACS Energy Letters 3 (2018) 2513–2519 [doi]

Zhou et al. Influence of Rotational Distortions on Li⁺– and Na⁺-Intercalation in Anti-NASICON Fe₂(MoO₄)₃; Chem. Mater., 2016, 28 , 4492 [doi]

Melot et al. Chemical and Structural Indicators for Large Redox Potentials in Fe-Based Positive Electrode Materials ACS Appl. Mater. Interfaces, 2014, 6, 10832 [doi]

Melot et al. Design and Preparation of Materials for Advanced Electrochemical Storage Acc. Chem. Res., 2013, 46, 1226 [doi]

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