Abstract: The present invention relates to a cathode active material for a secondary battery and a manufacturing method thereof. A cathode active material, according to one embodiment of the present invention, comprises silicon-based primary particles, and a particle size distribution of the silicon-based primary particles is D10?50 nm and D90?150 nm. The cathode active material suppresses or reduces tensile hoop stress generated in lithiated silicon particles during a charging of a battery to thus suppress a crack due to a volume expansion of the silicon particles and/or an irreversible reaction caused by the crack, such that the lifetime and capacity of the battery can be improved.

Abstract: The present invention relates to a method for producing silicon-based active material particles for a secondary battery and silicon-based active material particles. A method for producing silicon-based active material particles for a secondary battery according to an embodiment of the present invention may comprise: a step of providing silicon powder; a step of providing a pre-pulverization mixture in which the silicon powder is dispersed in a solvent for dispersion comprising an antioxidant; a step of applying mechanical compression and shear stress to the silicon powder of the pre-pulverization mixture to refine the silicon powder, thereby forming silicon particles having an oxygen content controlled by the antioxidant; and a step of drying the resulting material comprising the silicon particles to obtain silicon-based active material particles.

Abstract: The present invention relates to a silicon-based anode active material and a method for manufacturing the same. The silicon-based anode active material according to an embodiment of the present invention comprises: particles comprising silicon and oxygen combined with the silicon, and having a carbon-based conductive film coated on the outermost periphery thereof; and boron doped inside the particles, wherein with respect to the total weight of the particles and the doped boron, the boron is included in the amount of 0.01 weight % to 17 weight %, and the oxygen is included in the amount of 16 weight % to 29 weight %.

Abstract: The present invention relates to a silicon-based anode active material and a method of fabricating the same. The silicon-based anode active material according to an embodiment of the present invention comprises: particles comprising silicon and oxygen combined with the silicon, wherein a carbon-based conductive layer is coated with on outermost surface of the particles; and phosphorus doped in the particles, wherein a content of the phosphorus with respect to a total weight of the particles and the phosphorus doped in the particles have a range of 0.01 wt % to 15 wt %, and a content of the oxygen has a range of 9.5 wt % to 25 wt %.

Abstract: The present invention relates to a silicon anode active material capable of high capacity and high output, and a method for fabricating the same. A silicon anode active material according to an embodiment of the present invention includes a silicon core including silicon particles; and a double clamping layer having a silicon carbide layer on the silicon core and a silicon oxide layer between the silicon core and the silicon carbide layer.

Abstract: Provided is a negative active material and a lithium secondary battery including the negative active material. The negative active material for a secondary battery includes silicon particles, wherein circularities of the particles are determined by equation 1 below, and the circularities are 0.5 or greater and 0.9 or less, Circularity=2(pi×A)1/2/P??[Equation 1] where A denotes a projected area of the silicon particle that is two-dimensionally projected, and P denotes a circumferential length of the silicon particle that is two-dimensionally projected.

Abstract: The present invention relates to a method for preparing silicon-based active material particles for a secondary battery and silicon-based active material particles. The method for preparing silicon-based active material particles according to an embodiment of the present invention comprises the steps of: providing silicon powder; dispersing the silicon powder into an oxidant solvent to provide a mixture prior to grinding; fine-graining the silicon powder by applying mechanical compression and shear stress to the silicon powder in the mixture prior to grinding to produce silicon particles; producing a layer of chemical oxidation on the fine-grained silicon particles with the oxidant solvent while applying mechanical compression and shear stress to produce silicon-based active material particles; and drying the resulting product comprising the silicon-based active material particles to yield silicon-based active material particles.

Abstract: Provided is an anode active material for a secondary battery and a method of fabricating the anode active material. A silicon-based active material composite according to an embodiment of the inventive concept includes silicon and silicon oxide obtained by oxidizing at least a part of the silicon, and an amount of oxygen with respect to a total weight of the silicon and the silicon oxide is restricted to 9 wt % to 20 wt %.

Abstract: The present invention relates to a method for producing silicon-based active material particles for a secondary battery and silicon-based active material particles. A method for producing silicon-based active material particles for a secondary battery according to an embodiment of the present invention may comprise: a step of providing silicon powder; a step of providing a pre-pulverization mixture in which the silicon powder is dispersed in a solvent for dispersion comprising an antioxidant; a step of applying mechanical compression and shear stress to the silicon powder of the pre-pulverization mixture to refine the silicon powder, thereby forming silicon particles having an oxygen content controlled by the antioxidant; and a step of drying the resulting material comprising the silicon particles to obtain silicon-based active material particles.

Abstract: A composition comprising at least 50 weight % of a first particulate electroactive material and 3-15 weight % of a carbon additives mixture comprising elongate carbon nanostructures and carbon black, wherein: the elongate carbon nanostructures comprise at least a first elongate carbon nanostructure material and a different second elongate carbon nanostructure material; and the elongate carbon nanostructures: carbon black weight ratio is in the range 3:1 to 20:1.

Abstract: A lithium ion rechargeable battery cell includes an anode having electroactive material-containing particles wherein the electroactive material is selective from one or more of silicon, germanium, and tin. A cathode includes an active material adapted to incorporate lithium and also to liberate lithium electrochemically. The anode is adapted to incorporate lithium during lithiation. Also provided is an electrolyte, wherein the electrolyte includes both a cyclic carbonate having a vinyl group and a fluorinated cyclic carbonate. The total amount of the cyclic carbonate including a vinyl group and the fluorinated cyclic carbonate together is in the range of 3.5 wt % to 70 wt % based on the total weight of the electrolyte solution.

Abstract: A process for etching silicon to form silicon pillars on the etched surfaces, includes treating silicon with an etching solution that includes 5 to 10M HF 0.01 to 0.1M Ag+ ions and 0.02 to 0.2M NO3? ions. Further, NO3? ions in the form of alkali metal, nitric acid or ammonium nitrate salt is added to maintain the concentration of nitrate ions within the above range. The etched silicon is separated from the solution. The process provides pillars, especially for use as the active anode material in lithium ion batteries. The process is advantageous because it uses an etching bath containing only a small number of ingredients whose concentration needs to be controlled and it can be less expensive to operate than previous processes.

Abstract: There is provided a method of forming silicon anode material for rechargeable cells. The method includes providing a metal matrix, comprising no more than 30 wt % silicon, including silicon structures dispersed therein. The method further includes at least partially etching the metal matrix to at least partially isolate the silicon structures.

Abstract: A composite electrode includes an active component directly bonded to a current collector. The direct bonding provides a low resistance contact between the current collector and the active material. The active component can be provided as fibers of silicon. The fibers can be free or attached to a support.

Abstract: A lithium ion rechargeable battery cell includes an anode having electroactive material-containing particles wherein the electroactive material is selective from one or more of silicon, germanium, and tin. A cathode includes an active material adapted to incorporate lithium and also to liberate lithium electrochemically. The anode is adapted to incorporate lithium during lithiation. Also provided is an electrolyte, wherein the electrolyte includes both a cyclic carbonate having a vinyl group and a fluorinated cyclic carbonte. The total amount of the cyclic carbonate including a vinyl group and the fluorinated cyclic carbonate together is in the range of 3.5 wt % to 70 wt % based on the total weight of the electrolyte solution.

Abstract: A method of etching silicon of a material comprising silicon, the method comprising the steps of partially covering a silicon surface of the material comprising silicon with an elemental metal and then carrying out a metal-assisted chemical etching of the silicon by exposing the partially covered silicon surface to an etching composition, wherein at least some of the elemental metal for the metal-assisted chemical etching is formed by either: (a) exposing the silicon surface to a composition comprising metal ions, wherein the elemental metal forms by reduction of the metal ions and wherein the composition comprising metal ions is substantially free of HF, or (b) depositing the elemental metal directly onto the silicon surface.

Abstract: The present invention claims the addition of vinylene carbonate (VC) and optionally also fluoroethylene carbonate to the electrolyte of lithium ion cells having a structural silicon composite anode, i.e. an anode containing fibers or particles of silicon. The additive significantly improves the cycling performance of the cells. A VC content in the range 3.5-8 wt % based on the weight of the electrolyte has been found to be optimum.

Abstract: A process of etching silicon includes treating silicon, e.g. granules or bulk material, with an etching solution, including HF, Ag+ ions and nitrate ions thereby etching the silicon to form silicon having etched pillars on its surface, which silicon includes a surface deposit of silver. The etched silicon is then separated from the spent etching solution. The silver from the etched silicon is dissolved using nitric acid to form a solution containing Ag+ ions and nitrate ions. The solution containing Ag+ ions and nitrate ions is mixed with further HF to form a further etching solution. The further etching solution is used to treat further silicon. The pillars may be used as an anode material in a Li-ion battery.

Abstract: Pillared particles of silicon or silicon-comprising material and a method of fabricating the same are disclosed. These particles may be used to create both a composite anode structure with a polymer binder, a conductive additive and a metal foil current collector, and an electrode structure. The structure of the particles overcomes the problems of charge/discharge capacity loss.

Abstract: A method of etching silicon, the method comprising the steps of: partially covering at least one silicon surface of a material to be etched with copper metal; and exposing the at least one surface to an aqueous etching composition comprising an oxidant and a source of fluoride ions.