A solid electrolyte interface is formed on a silicon monoxide electrode in a battery cell. While the solid electrolyte interface is being formed on the silicon monoxide electrode, the battery cell is charged for one or more initial cycles.

Systems for and methods of treating a fluid containing siloxanes, silanes and/or other silicon compounds. A hot box is configured to receive an initial flow of the fluid, react the flow with water at a temperature and pressure suitable for hydrolysis to generate a first treated flow, in which at least a portion is hydrolyzed to produce silicon dioxide and methane, and discharge the first treated flow. A solid removal mechanism can be configured to receive the first treated flow, separate at least a portion of the silicon dioxide as solid material, and discharge the remaining components as a second treated flow. Techniques of the present disclosure can lead to very low siloxane levels.

Systems for and methods of treating a fluid containing siloxanes, silanes and/or other silicon compounds. A hot box is configured to receive an initial flow of the fluid, react the flow with water at a temperature and pressure suitable for hydrolysis to generate a first treated flow, in which at least a portion is hydrolyzed to produce silicon dioxide and methane, and discharge the first treated flow. A solid removal mechanism can be configured to receive the first treated flow, separate at least a portion of the silicon dioxide as solid material, and discharge the remaining components as a second treated flow. Techniques of the present disclosure can lead to very low siloxane levels.

A negative electrode material includes silicon-based particles and graphite particles. In a case that a D.sub.n50/D.sub.v50 ratio of the graphite particles is A and a D.sub.n50/D.sub.v50 ratio of the silicon-based particles is B, the following conditional expressions (1) to (3) are satisfied: 0.1≤A≤0.65 (1); 0.3≤B≤0.85 (2); and B>A (3), where, D.sub.v50 is a particle diameter of particles measured when a cumulative volume fraction in a volume-based distribution reaches 50%, and D.sub.n50 is a particle diameter of particles measured when a cumulative number fraction in a number-based distribution reaches 50%. The present invention further provides a negative electrode plate, a lithium-ion secondary battery or electrochemical device containing the negative electrode plate, and an electronic device containing the lithium-ion secondary battery and/or electrochemical device.

A negative electrode material for a secondary battery including: a matrix including silicon (Si), one or more doping elements (D) selected from the group consisting of alkali metals, alkaline earth metals, and post transition metals, and oxygen (O), based on an element component; and silicon nanoparticles dispersed and embedded in the matrix, wherein the negative electrode material has composition uniformity, and a ratio (A1/A2) between an area of a first peak (A1) and an area of a second peak (A2) satisfying 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.

This application provides a silicon-based material, a preparation method thereof, and a secondary battery, a battery module, a battery pack, and an apparatus associated therewith. The silicon-based material includes a core structure and a coating layer provided on at least partial surface of the core structure, where the core structure includes both a silicon phase and a lithium metasilicate phase, and a particle size P of the lithium metasilicate phase is ≥30 nm. The silicon-based material of this application can not only increase energy density of a secondary battery with the silicon phase, but also improve structural stability and chemical stability of the silicon-based material, so that the secondary battery can deliver satisfactory and balanced cycling performance and first-cycle coulombic efficiency in overall.

An object of the present invention is to provide active material particles excellent in ion uptake ability. The silicon-based active material particles according to the present invention comprise a layer structure. Here, the “silicon-based active material particles” are, for example, active material particles for forming a negative electrode of a lithium ion secondary battery. Examples of the active material particles for forming the negative electrode of the lithium ion secondary battery include so-called Si-based active materials such as silicon (Si), silicon oxide (SiO.sub.x), metal element-containing silicon oxide containing alkaline metal elements such as lithium (Li) and alkaline earth metal elements such as magnesium (Mg), silicon alloys. The thickness of the layer in the active material particles is preferably 1 μm or less. Here, the thickness of the layer is preferably 0.01 μm or more.

A negative electrode active material including a core containing SiO.sub.x (0≤x<2) and a lithium-containing compound, and a shell disposed on the core and containing SiO.sub.x (0≤x<2) and magnesium silicate.

The present application provide a silicon-oxygen compound, a secondary battery using it, and related battery modules, battery packs, and devices. The silicon-oxygen compound provided by the present application has a formula of SiO.sub.x, in which x satisfies 0<x<2. The silicon-oxygen compound contains both sulfur and aluminum element, and the sulfur element is present in an amount of 20 ppm˜300 ppm. The mass ratio of sulfur element to aluminum element is from 1.5 to 13.0. A secondary battery uses the silicon-oxygen compound provided in the present application, so that the secondary battery can have both long-cycle performance and high initial coulombic efficiency.

Disclosed is a negative electrode active material which includes: a silicon oxide composite including i) Si, ii) a silicon oxide represented by SiO.sub.x (0 < x ≤ 2), and iii) magnesium silicate containing Si and Mg; and a carbon coating layer positioned on the surface of the silicon oxide composite and including a carbonaceous material, wherein X-ray diffractometry of the negative electrode active material shows peaks of Mg.sub.2SiO.sub.4 and MgSiO.sub.3 at the same time and shows no peak of MgO; the ratio of peak intensity, I (Mg.sub.2SiO.sub.4)/I (MgSiO.sub.3), which is intensity I (Mg.sub.2SiO.sub.4) of peaks that belong to Mg.sub.2SiO.sub.4 to intensity I (MgSiO.sub.3) of peaks that belong to MgSiO.sub.3 is smaller than 1, the peaks that belong to Mg.sub.2SiO.sub.4 are observed at 2θ = 32.2 ± 0.2°, and the peaks that belong to MgSiO.sub.3 are observed at 2θ = 30.9 ± 0.2°.