This paper reports a Si‐Ti‐Ni ternary alloy developed for commercial application as an anode material for lithium ion batteries. Our alloy exhibits a stable capacity above 900 mAh g−1 after 50 cycles and a high coulombic efficiency of up to 99.7% during cycling. To enable a highly reversible nano‐Si anode, melt spinning is employed to embed nano‐Si particles in a Ti4Ni4Si7 matrix. The Ti4Ni4Si7 matrix fulfills two important purposes. First, it reduces the maximum stress evolved in the nano‐Si particles by applying a compressive stress to mechanically confine Si expansion during lithiation. And second, the Ti4Ni4Si7 matrix is a good mixed conductor that isolates nano‐Si from the liquid electrolyte, thus preventing parasitic reactions responsible for the formation of a solid electrolyte interphase. Given that a coulombic efficiency above 99.5% is rarely reported for Si based anode materials, this alloy's performance suggests a promising new approach to engineering Si anode materials.

We report the direct observation of microstructural changes of LixSi electrode with lithium insertion. HRTEM experiments confirm that lithiated amorphous silicon forms a shell around a core made up of the unlithiated silicon and that fully lithiated silicon contains a large number of pores of which concentration increases toward the center of the particle. Chemomechanical modeling is employed in order to explain this mechanical degradation resulting from stresses in the LixSi particles with lithium insertion. Because lithiation‐induced volume expansion and pulverization are the key mechanical effects that plague the performance and lifetime of high‐capacity Si anodes in lithium‐ion batteries, our observations and chemomechanical simulation provide important mechanistic insight for the design of advanced battery materials.

Recrystallization and grain growth of gold bonding wire have been investigated with electron backscatter diffraction (EBSD). The bonding wires were wire-drawn to an equivalent strain greater than 11.4 with final diameter between 25 and 30 mm. Annealing treatments were carried out in a salt bath at 300 °C, and 400 °C for 1, 10, 60 minutes, and 1 day. The textures of the drawn gold wires contain major ͗111͘, minor ͗100͘, and small fractions of complex fiber components. The ͗100͘ oriented regions are located in the center and surface of the wire, and the complex fiber components are located near the surface. The ͗111͘ oriented regions occur throughout the wire. Maps of the local Taylor factor can be used to distinguish the ͗111͘ and ͗100͘ regions. The ͗111͘ oriented grains have large Taylor factors and might be expected to have higher stored energy as a result of plastic deformation compared to the ͗100͘ regions. Both ͗111͘ and ͗100͘ grains grow during annealing. In particular, ͗100͘ grains in the surface and the center part grow into the ͗111͘ regions at 300 °C and 400°C. Large misorientations (angles Ͼ40 deg) are present between the ͗111͘ and ͗100͘ regions, which means that the boundaries between them are likely to have high mobility. Grain average misorientation (GAM) is greater in the ͗111͘ than in the ͗100͘ regions. It appears that the stored energy, as indicated by geometrically necessary dislocation content in the subgrain structure, is larger in the ͗111͘ than in the ͗100͘ regions.

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