Provided is a negative electrode material for a secondary battery, which is in a particle form including: a matrix including a silicon oxide, a composite oxide of silicon and one or more doping elements selected from the group consisting of alkali metals, alkaline earth metals, and post transition metals, or a mixture thereof; and silicon nanoparticles dispersed and embedded in the matrix, wherein a compressive strength (St) of the particles is 100 MPa or more, and a ratio (A.sub.1/A.sub.2) between an area of a first peak (A.sub.1) and an area of a second peak (A.sub.2) satisfies 0.8 to 6, a diffraction angle 2θ being positioned in a range of 10° to 27.4° in the first peak and being positioned in a range of 28±0.5° in the second peak, in an X-ray diffraction pattern using a CuKα ray.

An electrode for a lithium-ion battery. The electrode has at least one porous silicon layer and a copper layer. There is also described a battery with such an electrode, a method for producing an electrode of this kind, and the use of an electrode of this kind in a battery.

A silicon material can include a composition with at least about 50% silicon, at most about 45% carbon, and at most about 10% oxygen. The silicon material can have an external expansion that is less than about 40%. The silicon material can include silicon nanoparticles, which can cooperatively form clusters. The silicon nanoparticles can be porous.

A silicon material can include a composition with at least about 50% silicon, at most about 45% carbon, and at most about 10% oxygen. The silicon material can have an external expansion that is less than about 40%. The silicon material can include silicon nanoparticles, which can cooperatively form clusters. The silicon nanoparticles can be porous.

Embodiments generally relate to methods for depositing silicon-phosphorous materials, and more specifically, relate to using silicon-phosphorous compounds in vapor deposition processes (e.g., epitaxy, CVD, or ALD) to deposit silicon-phosphorous materials. In one or more embodiments, a method for forming a silicon-phosphorous material on a substrate is provided and includes exposing the substrate to a deposition gas containing one or more silicon-phosphorous compounds during a deposition process and depositing a film containing the silicon-phosphorous material on the substrate. The silicon-phosphorous compound has the chemical formula [(R.sub.3-vH.sub.vSi)—(R.sub.2-wH.sub.wSi).sub.n].sub.xPH.sub.yR′.sub.z, where each instance of R and each instance of R′ are independently an alkyl or a halogen, n is 0, 1, or 2; v is 0, 1, 2, or 3; w is 0, 1, or 2; x is 1, 2, or 3; y is 0, 1, or 2; z is 0, 1, or 2, and where x+y+z=3.

A negative electrode active material for a secondary battery includes a lithium silicate phase, and a silicon phase dispersed in the lithium silicate phase. An electron diffraction image of the negative electrode active material obtained using a transmission electron microscope has a spot image, and an average particle diameter of the negative electrode active material is 8 μm or less.

A new silicon material is provided. A negative electrode active material including an Al- and O-containing silicon material, the Al- and O-containing silicon material being configured such that a mass % of Al (W.sub.Al %) satisfies 0<W.sub.Al<1, and a peak indicating Al—O bond is observed in a range of 1565 to 1570 eV in an X-ray absorption fine structure measurement for a K shell of Al.

A polysilicon fractured product includes fractured pieces including a ridge portion generated by fracturing a polysilicon rod. An average radius of curvature (r) of the fractured pieces is 50 μm or more at a tip end of a ridge portion having an angle of 70° or less. The polysilicon fractured product is obtained by a method including fracturing a polysilicon rod to obtain fractured pieces, and etching at an etching speed of 2.5 μm/min or less to achieve an etching depth of 5 μm or more by immersing the fractured pieces obtained in the fracturing in an etching solution.

A textured structure of a crystalline silicon solar cell that is mainly constructed by a plurality of micro-structures similar to inverted pyramids; the lower part of the micro-structure similar to the inverted pyramid is an inverted pyramidal structure, and the upper part thereof is an inverted circular truncated conical structure; and the top of the micro-structure similar to the inverted pyramid is selected from one or more of a circle, an oval, or a closed figure enclosed by multiple curves. Experiments prove that the conversion efficiency of a cell piece may be improved by 0.25-0.4%, thereby obtaining unexpected effects.

A textured structure of a crystalline silicon solar cell that is mainly constructed by a plurality of micro-structures similar to inverted pyramids; the lower part of the micro-structure similar to the inverted pyramid is an inverted pyramidal structure, and the upper part thereof is an inverted circular truncated conical structure; and the top of the micro-structure similar to the inverted pyramid is selected from one or more of a circle, an oval, or a closed figure enclosed by multiple curves. Experiments prove that the conversion efficiency of a cell piece may be improved by 0.25-0.4%, thereby obtaining unexpected effects.