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<p>Dislocation dynamics at the atomic scale play a significant role in phase transformations and mechanical degradation of layered cathode materials in Na-ion batteries (NIBs), yet their fundamental behavior remains poorly understood. Here, we employ first-principle calculations to investigate dislocation-mediated processes in a range of O3- and O'3-type layered transition metal (TM) oxides, Na(TM)O₂, with TM = Ti, Cr, Mn, Fe, Co, and Ni. Generalized stacking fault <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\gamma\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>γ</mi> </math></EquationSource> </InlineEquation>-surfaces are computed to quantify the influence of TM chemistry on stacking sequence energetics. These <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\gamma\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>γ</mi> </math></EquationSource> </InlineEquation>-surfaces, combined with elastic tensor data, inform a semi-discrete variational Peierls–Nabarro model to characterize dislocation core structures and Peierls stresses. Our results reveal narrow dislocation cores and partial splitting behaviors governed by the γ-surface topology and material elasticity. We further propose a dislocation-driven mechanism for the O3<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\leftrightarrow\)</EquationSource> <EquationSource Format="MATHML"><math> <mo>↔</mo> </math></EquationSource> </InlineEquation>P3 phase transformation, wherein partial dislocation motion facilitates the broadening of stacking faults during desodiation. This work establishes a detailed first-principles computational framework for understanding dislocation-mediated degradation pathways in layered oxides, offering atomistic-scale insights for the design of more robust NIB cathode materials.</p>

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First-principles computation of dislocation structures and stress-driven phase transformations in layered oxides for Na-ion batteries

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  • 发表日期：

    2026年1月20日

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  • Oier Arcelus,
  • Javier Carrasco

摘要

Dislocation dynamics at the atomic scale play a significant role in phase transformations and mechanical degradation of layered cathode materials in Na-ion batteries (NIBs), yet their fundamental behavior remains poorly understood. Here, we employ first-principle calculations to investigate dislocation-mediated processes in a range of O3- and O'3-type layered transition metal (TM) oxides, Na(TM)O₂, with TM = Ti, Cr, Mn, Fe, Co, and Ni. Generalized stacking fault \(\gamma\) γ -surfaces are computed to quantify the influence of TM chemistry on stacking sequence energetics. These \(\gamma\) γ -surfaces, combined with elastic tensor data, inform a semi-discrete variational Peierls–Nabarro model to characterize dislocation core structures and Peierls stresses. Our results reveal narrow dislocation cores and partial splitting behaviors governed by the γ-surface topology and material elasticity. We further propose a dislocation-driven mechanism for the O3 \(\leftrightarrow\) ↔ P3 phase transformation, wherein partial dislocation motion facilitates the broadening of stacking faults during desodiation. This work establishes a detailed first-principles computational framework for understanding dislocation-mediated degradation pathways in layered oxides, offering atomistic-scale insights for the design of more robust NIB cathode materials.