Provided are a porous silicon-based anode active material including crystalline silicon (Si) particles, and a plurality of pores on surfaces, or the surfaces and inside of the crystalline silicon particles, wherein at least one plane of crystal planes of at least a portion of the plurality of pores includes a (100) plane, and a method of preparing the porous silicon-based anode active material. Since a porous silicon-based anode active material of the present invention may allow volume expansion, which is occurred during charge and discharge of a lithium secondary battery, to be concentrated on pores instead of the outside of the anode active material, the porous silicon-based anode active material may improve life characteristics of the lithium secondary battery by efficiently controlling the volume expansion.

Provided are a porous silicon-based anode active material including crystalline silicon (Si) particles, and a plurality of pores on surfaces, or the surfaces and inside of the crystalline silicon particles, wherein at least one plane of crystal planes of at least a portion of the plurality of pores includes a (100) plane, and a method of preparing the porous silicon-based anode active material. Since a porous silicon-based anode active material of the present invention may allow volume expansion, which is occurred during charge and discharge of a lithium secondary battery, to be concentrated on pores instead of the outside of the anode active material, the porous silicon-based anode active material may improve life characteristics of the lithium secondary battery by efficiently controlling the volume expansion.

Provided is a composite anode active material including: a carbonaceous material; a metal alloyable with lithium, located on a surface of the carbonaceous material; and a silicon coating layer located on a surface of the carbonaceous material, on a surface of the metal alloyable with lithium, or a combination thereof.

Provided is a composite anode active material including: a carbonaceous material; a metal alloyable with lithium, located on a surface of the carbonaceous material; and a silicon coating layer located on a surface of the carbonaceous material, on a surface of the metal alloyable with lithium, or a combination thereof.

The use of a C10~C34 fatty acids compound in the preparation of a the electrode materials for lithium-ion battery improves the coating uniformity of electrode materials prepared with solid-state method. The fatty acid provided by the invention is a dispersant, which achieves the uniformly dispersion of the coating material on the surface of battery material, and significantly increases the coating uniformity of the electrode material coated with solid-state method, it greatly improves the feasibility of manufacturing the electrode material of lithium-ion battery with solid-state method, and is conducive to the more economical and simpler manufacture of electrode material.

The use of a C10~C34 fatty acids compound in the preparation of a the electrode materials for lithium-ion battery improves the coating uniformity of electrode materials prepared with solid-state method. The fatty acid provided by the invention is a dispersant, which achieves the uniformly dispersion of the coating material on the surface of battery material, and significantly increases the coating uniformity of the electrode material coated with solid-state method, it greatly improves the feasibility of manufacturing the electrode material of lithium-ion battery with solid-state method, and is conducive to the more economical and simpler manufacture of electrode material.

Powder comprising particles comprising a matrix material and silicon-based domains dispersed in this matrix material, whereby either part of the silicon-based domains are present in the form of agglomerates of silicon-based domains whereby at least 98% of these agglomerates have a maximum size of 3 μm or less, or the silicon-based domains are not at all agglomerated into agglomerates.

Powder comprising particles comprising a matrix material and silicon-based domains dispersed in this matrix material, whereby either part of the silicon-based domains are present in the form of agglomerates of silicon-based domains whereby at least 98% of these agglomerates have a maximum size of 3 μm or less, or the silicon-based domains are not at all agglomerated into agglomerates.

A method for forming a porous silicon material can include forming a mixture of silicon, carbon, and an etchant element, solidifying the mixture, removing the etchant element to form pores within the silicon material. The porous silicon material can include a distribution of pores with an average pore diameter between about 10 nm and 500 nm, wherein the silicon particle comprises a silicon carbon composite comprising 1-5% carbon by mass, 1-5% oxygen by mass, and 90-98% silicon by mass.

In the present invention, as a bag to store polycrystalline silicon ingots, there is used a bag in which the concentration of paraffinic hydrocarbons in a concentrate of solvent-soluble components obtained by Soxhlet extraction using acetone as a solvent is lower than 300 ppmw as a value measured by GC-MS method; the concentration of antioxidants, lower than 10 ppmw; the concentration of ultraviolet absorbents, lower than 5 ppmw; and the concentration of antistatic agents and surfactants, lower than 50 ppmw. Then, when the polycrystalline silicon ingots are packed, preferably, the polycrystalline silicon ingots are put in the storage bag; thereafter, the storage bag is sealed; further, the storage bag is put and sealed in a linear low-density polyethylene bag containing an antistatic agent or a surfactant added in the bag material.