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Abstract Layered transition‐metal dichalcogenides (TMDs) have shown promise to replace carbon‐based compounds as suitable anode materials for Lithium‐ion batteries (LIBs) owing to facile intercalation and de‐intercalation of lithium (Li) during charging and discharging, respectively. While the intercalation mechanism of Li in mono‐ and bi‐layer TMDs has’ been thoroughly examined, mechanistic understanding of Li intercalation‐induced phase transformation in bulk or films of TMDs is still largely unexplored. This study investigates possible scenarios during sequential Li intercalation and aims to gain a mechanistic understanding of the phase transformation in bulk MoS2using density functional theory (DFT) calculations. The manuscript examines the role of concentration and distribution of Li‐ions on the formation of dual‐phase 2H‐1T microstructures that have been observed experimentally. The study demonstrates that lithiation would proceed in a systematic layer‐by‐layer manner wherein Li‐ions diffuse into successive interlayer spacings to render local phase transformation of the adjacent MoS2layers from 2H‐to‐1T phase in the multilayered MoS2. This local phase transition is attributed to partial ionization of Li and charge redistribution around the metal atoms and is followed by subsequent lattice straining. In addition, the stability of single‐phase vs. multiphase intercalated microstructures, and the origins of structural changes accompanying Li‐ion insertion are investigated at atomic scales.
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This content will become publicly available on December 12, 2026
Intercalation‐Induced Phase Transitions in Ferroelectric α‐In 2 Se 3
Abstract Specific ions can be intercalated into functional materials using the electrolyte gating technique, which has been widely used to regulate channel conductance in transistors and develop low‐power neuromorphic devices. However, in these devices, fundamental exploration of ion intercalation‐induced structural phase transitions remains largely overlooked and rarely explored. Here, the lithium‐based electrolyte gating technique is used to probe the collective interactions between ions, lattices, and electrons in a van der Waals ferroelectric semiconductor α‐In2Se3. Using a polymer electrolyte as the lithium‐ion reservoir and α‐In2Se3as the channel material, the intercalated lithium concentration via a gate electric field is modulated. This manipulation drives a phase transition in α‐In2Se3from a ferroelectric semiconductor to a dirty metal and finally to a metal, accompanied by a structural transformation. Concurrently, with enhanced intercalation, the ferroelectric hysteresis window progressively narrows and eventually disappears, indicating the evolution from switchable to non‐switchable polarization. This study represents a promising platform for the artificial construction of correlated material systems, enabling a systematic investigation into the interaction of ferroelectricity and electronic conduction using ion intercalation.
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- Award ID(s):
- 2429995
- PAR ID:
- 10653299
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Science
- ISSN:
- 2198-3844
- Page Range / eLocation ID:
- e13712
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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