Stress generation during anisotropic lithiation in silicon nanopillar electrodes: A reactive force field study

Cao, Luoxia; Yang, Hui; Fan, Fenliang

doi:10.1016/j.physleta.2019.125955

Cited by 13 publications

(5 citation statements)

References 37 publications

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“…Nanostructures have been studied also by Fan et al 13 , who computed the mechanical response of (111)-oriented c-Si nanopillar during lithiation. Similar work has been carried out for the (100)-oriented c-Si nanopillar by Cao et al 14 . Tang et al 15 investigated the evolution and survivability of porosity in Si nanosheets during the lithiation and delithiation processes.…”

Section: Introductionsupporting

confidence: 58%

Characterization of amorphous Li_xSi structures from ReaxFF via accelerated exploration of local minima

Fernandez

Paz

Otero

et al. 2021

Phys. Chem. Chem. Phys.

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Section: Introductionsupporting

confidence: 58%

Characterization of amorphous Li_xSi structures from ReaxFF via accelerated exploration of local minima

Fernandez

Paz

Otero

et al. 2021

Phys. Chem. Chem. Phys.

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“…Consequently, they failed to capture the microstructural changes and stress generated in a-Si and c-Si during lithiation. Two recent atomistic simulations obtained the isotropic and anisotropic volume expansions of SiNPs with a diameter of 10.0 nm, , but the generated stresses were different from previous theoretical predictions. ,, Moreover, the atomistic mechanisms giving rise to plastic flow of Li x Si alloys and lithiation-induced fracture have not been studied.…”

Section: Introductionmentioning

confidence: 84%

“…Therefore, it can be concluded that the CG and FIRE methods are more efficient for fine energy minimization, while the NVE dynamic relaxation is better for coarse energy minimization with a significant energy change. Note that the lithiated SiNPs in previous MD works were only relaxed by the CG method, , possibly leading to the inconsistent stress distribution compared with theoretical predictions …”

Section: New Structural Relaxation Approachmentioning

confidence: 99%

A First Molecular Dynamics Study for Modeling the Microstructure and Mechanical Behavior of Si Nanopillars during Lithiation

Shuang

Aifantis

2021

ACS Appl. Mater. Interfaces

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This is the first study that employs large-scale atomistic simulations to examine the stress generation and deformation mechanisms of various Si nanopillars (SiNPs) during Li-ion insertion. First, a new robust and effective minimization approach is proposed to relax a lithiated amorphous SiNP (a-SiNP), which outperforms the known methods. Using this new method, our simulations are able to successfully capture the experimental morphological changes and volume expansions that SiNPs, hollow a-SiNPs, and solid crystalline SiNPs (c-SiNPs) experience upon maximum lithiation. These simulations enable us to selectively track the displacement of Si atoms and their atomic shear strain in the Li 3.75 Si alloy region, allowing us to observe the plastic flow and illustrate the atomistic mechanism of lithiationinduced deformation for various SiNPs for the first time. Based on the simulation results, a simple fracture mechanistic model is used to determine the fracture resistance of SiNPs, showing that the hollow a-SiNP is the optimal form of Si as an anode because it has the highest fracture resistance. The crack propagation simulation suggests that the preexisting dislocations in pristine c-Si can contribute toward the fracture of c-SiNPs during lithiation. These findings can guide the design of new Si-based anode geometries for the next-generation Li-ion batteries.

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“…It is well recognized that the stresses generated in the silicon-based materials regulate the kinetics of chemical reactions and potential response [25,49]. The mechanism by which the tensile/compressive stress facilitates/retards the diffusion of Li atoms may cause the inhomogeneous growth of the lithiated phase, leading to the nonuniform distribution of morphology and Li ion concentration [17,45,[50][51][52][53]. To further study this, the stress evolution is quantitively investigated.…”

Section: Stress-regulated Effects During Lithiationmentioning

confidence: 99%

Molecular Understanding of Electrochemical–Mechanical Responses in Carbon-Coated Silicon Nanotubes during Lithiation

Chen

Liu

et al. 2021

Nanomaterials

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Carbon-coated silicon nanotube (SiNT@CNT) anodes show tremendous potential in high-performance lithium ion batteries (LIBs). Unfortunately, to realize the commercial application, it is still required to further optimize the structural design for better durability and safety. Here, the electrochemical and mechanical evolution in lithiated SiNT@CNT nanohybrids are investigated using large-scale atomistic simulations. More importantly, the lithiation responses of SiNW@CNT nanohybrids are also investigated in the same simulation conditions as references. The simulations quantitatively reveal that the inner hole of the SiNT alleviates the compressive stress concentration between a-LixSi and C phases, resulting in the SiNT@CNT having a higher Li capacity and faster lithiation rate than SiNW@CNT. The contact mode significantly regulates the stress distribution at the inner hole surface, further affecting the morphological evolution and structural stability. The inner hole of bare SiNT shows good structural stability due to no stress concentration, while that of concentric SiNT@CNT undergoes dramatic shrinkage due to compressive stress concentration, and that of eccentric SiNT@CNT is deformed due to the mismatch of stress distribution. These findings not only enrich the atomic understanding of the electrochemical–mechanical coupled mechanism in lithiated SiNT@CNT nanohybrids but also provide feasible solutions to optimize the charging strategy and tune the nanostructure of SiNT-based electrode materials.

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Stress generation during anisotropic lithiation in silicon nanopillar electrodes: A reactive force field study

Cited by 13 publications

References 37 publications

Characterization of amorphous Li_xSi structures from ReaxFF via accelerated exploration of local minima

Characterization of amorphous Li_xSi structures from ReaxFF via accelerated exploration of local minima

A First Molecular Dynamics Study for Modeling the Microstructure and Mechanical Behavior of Si Nanopillars during Lithiation

Molecular Understanding of Electrochemical–Mechanical Responses in Carbon-Coated Silicon Nanotubes during Lithiation

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Stress generation during anisotropic lithiation in silicon nanopillar electrodes: A reactive force field study

Cited by 13 publications

References 37 publications

Characterization of amorphous LixSi structures from ReaxFF via accelerated exploration of local minima

Characterization of amorphous LixSi structures from ReaxFF via accelerated exploration of local minima

A First Molecular Dynamics Study for Modeling the Microstructure and Mechanical Behavior of Si Nanopillars during Lithiation

Molecular Understanding of Electrochemical–Mechanical Responses in Carbon-Coated Silicon Nanotubes during Lithiation

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Characterization of amorphous Li_xSi structures from ReaxFF via accelerated exploration of local minima

Characterization of amorphous Li_xSi structures from ReaxFF via accelerated exploration of local minima