Anisotropic swelling and fracture of silicon nanowires during lithiation.
نویسندگان
چکیده
We report direct observation of an unexpected anisotropic swelling of Si nanowires during lithiation against either a solid electrolyte with a lithium counter-electrode or a liquid electrolyte with a LiCoO(2) counter-electrode. Such anisotropic expansion is attributed to the interfacial processes of accommodating large volumetric strains at the lithiation reaction front that depend sensitively on the crystallographic orientation. This anisotropic swelling results in lithiated Si nanowires with a remarkable dumbbell-shaped cross section, which develops due to plastic flow and an ensuing necking instability that is induced by the tensile hoop stress buildup in the lithiated shell. The plasticity-driven morphological instabilities often lead to fracture in lithiated nanowires, now captured in video. These results provide important insight into the battery degradation mechanisms.
منابع مشابه
Orientation-dependent interfacial mobility governs the anisotropic swelling in lithiated silicon nanowires.
Recent independent experiments demonstrated that the lithiation-induced volume expansion in silicon nanowires, nanopillars, and microslabs is highly anisotropic, with predominant expansion along the <110> direction but negligibly small expansion along the <111> direction. The origin of such anisotropic behavior remains elusive. Here, we develop a chemomechanical model to study the phase evoluti...
متن کاملReaction Front Evolution during Electrochemical Lithiation of Crystalline Silicon Nanopillars
Silicon is one of the most promising anode materials for use in rechargeable lithium-ion batteries due to its high theoretical specific capacity of 4200 mAhg 1 and low cost. However, this high lithium storage capacity results in enormous volume expansion and contraction during electrochemical lithiation and delithiation, which can induce mechanical fracture and severe capacity fading. Recently,...
متن کاملNovel size and surface oxide effects in silicon nanowires as lithium battery anodes.
With its high specific capacity, silicon is a promising anode material for high-energy lithium-ion batteries, but volume expansion and fracture during lithium reaction have prevented implementation. Si nanostructures have shown resistance to fracture during cycling, but the critical effects of nanostructure size and native surface oxide on volume expansion and cycling performance are not unders...
متن کاملA chemo-mechanical model of lithiation in silicon
We present a chemo-mechanical model to investigate the lithiation-induced phase transformation, morphological evolution, stress generation and fracture in crystalline silicon nanowires (c-SiNWs). The model couples lithium (Li) diffusion with elasto-plastic deformation in a three-dimensional (3D) setting. Several key features observed from recent transmission electron microscopy (TEM) studies ar...
متن کاملThe effect of metallic coatings and crystallinity on the volume expansion of silicon during electrochemical lithiation/delithiation
icle as: M.T. McDow hiation/delithiatio Abstract Applying surface coatings to alloying anodes for Li-ion batteries can improve rate capability and cycle life, but it is unclear how this second phase affects mechanical deformation during electrochemical reaction. Here, in-situ transmission electron microscopy is employed to investigate the electrochemical lithiation and delithiation of silicon n...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Nano letters
دوره 11 8 شماره
صفحات -
تاریخ انتشار 2011