Size effects on strength and plasticity of vanadium nanopillars

Han, Seung Min; Bozorg-Grayeli, Tara; Groves, J. R.; Nix, William D.

doi:10.1016/j.scriptamat.2010.08.011

Cited by 89 publications

(50 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the size effect plot in Fig. 3B, which shows that, at room temperature, the power law slope of −0.68 for Li is close to those of V (−0.79) and Nb (−0.93) (19), the two bcc metals exhibiting fcc-like deformation and size effect exponent. This plot also reveals that, relative to the shear modulus, Li is the strongest of all reported bcc metals within the studied size range; for example, at a pillar diameter of 1 μm (D/b = 3,300), the relative strength of Li is a factor of 1.7 higher than V and Nb, and a factor of 2.3 higher than W. At 363 K, the size effect slope becomes −1.00, whereas the normalized strength decreases by a factor of ∼3.5 compared with room temperature over the entire size range.…”

supporting

confidence: 89%

Enhanced strength and temperature dependence of mechanical properties of Li at small scales and its implications for Li metal anodes

Ahmad

Aryanfar

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

247

191

View full text Add to dashboard Cite

Most next-generation Li ion battery chemistries require a functioning lithium metal (Li) anode. However, its application in secondary batteries has been inhibited because of uncontrollable dendrite growth during cycling. Mechanical suppression of dendrite growth through solid polymer electrolytes (SPEs) or through robust separators has shown the most potential for alleviating this problem. Studies of the mechanical behavior of Li at any length scale and temperature are limited because of its extreme reactivity, which renders sample preparation, transfer, microstructure characterization, and mechanical testing extremely challenging. We conduct nanomechanical experiments in an in situ scanning electron microscope and show that micrometer-sized Li attains extremely high strengths of 105 MPa at room temperature and of 35 MPa at 90°C. We demonstrate that single-crystalline Li exhibits a power-law size effect at the micrometer and submicrometer length scales, with the strengthening exponent of −0.68 at room temperature and of −1.00 at 90°C. We also report the elastic and shear moduli as a function of crystallographic orientation gleaned from experiments and first-principles calculations, which show a high level of anisotropy up to the melting point, where the elastic and shear moduli vary by a factor of ∼4 between the stiffest and most compliant orientations. The emergence of such high strengths in small-scale Li and sensitivity of this metal's stiffness to crystallographic orientation help explain why the existing methods of dendrite suppression have been mainly unsuccessful and have significant implications for practical design of future-generation batteries.dendrite | size effect | elastic anisotropy | dislocation | elevated temperature I ncreased adoption of electric vehicles requires an improvement in the energy density of rechargeable Li ion batteries. Li metal anode is a common and necessary ingredient in commercialization pathways for next-generation Li ion batteries. In the near term, Li metal coupled with an advanced cathode could lead to a specific energy of 400 Wh/kg at the cell level, which represents 200% improvement over current state of the art (1). In the longer term, Li metal coupled with a S and O 2 cathode could lead to even higher specific energies of >500 Wh/kg. Despite over 40 y of research, overcoming the uncontrollable dendrite growth during cycling has remained an insurmountable obstacle for Li-based components (2). Among multiple attempted approaches to eliminate or even reduce the dendrite growth, mechanical suppression has emerged as one of the most promising routes. In their pioneering theoretical work, Monroe et al. (3) considered a solid polymer electrolyte (SPE) in contact with a Li metal electrode and performed a linear stability analysis of the deformation at the interface. They used linear elasticity to compute the stresses generated at the interface due to small deformations. They found that the dendrite growth decays with time if the shear modulus of the SPE is higher than about t...

show abstract

supporting

confidence: 89%

Enhanced strength and temperature dependence of mechanical properties of Li at small scales and its implications for Li metal anodes

Ahmad

Aryanfar

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

247

191

View full text Add to dashboard Cite

show abstract

“…The result of this normalization yielded a power-law exponent of ∼−0.6. Recently, the small-scale mechanical properties of body centered cubic (BCC) metals have also been explored in uniaxial compression and tension [28][29][30][31]34,37,38,40,51]. It is interesting to note that the deformation characteristics and size effects observed for single-crystalline BCC nanopillars deviate from FCC specimens for reasons attributed to crystal structure [28,51].…”

Section: Influence Of Strain Rate and Nanopillar Sizementioning

confidence: 99%

Fabrication, microstructure, and mechanical properties of tin nanostructures

Burek

Budiman

Jahed

et al. 2011

Materials Science and Engineering: A

View full text Add to dashboard Cite

“…Electroplating methods have also produced Cu pillars for both uniaxial tension and compression testing, with the additional capability of creating pillars with diameters below 100 nm [19,20]. Beyond fcc, the effect of size on strength for a variety of crystal structures has been investigated, including bcc [21][22][23][24][25][26][27][28][29] and hcp [30][31][32]. Computational techniques like molecular dynamics (MD) [33][34][35] and dislocation dynamics (DD) [36,37] have also been widely utilized to shed light on the underlying defect mechanisms leading to this size-dependent strengthening.…”

Section: Introductionmentioning

confidence: 99%