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°.

Provided is a secondary battery which includes: one or more positive electrodes including a positive electrode active material layer; a plurality of negative electrodes including a first negative electrode including a silicon-based active material and a second negative electrode including a carbon-based active material; a separator; and an electrolyte, wherein the positive electrode and the negative electrode are alternately stacked with the separators interposed therebetween, and the ratio of weight of the silicon-based active material included in the first negative electrode and weight of the carbon-based active material included in the second negative electrode is in the range of 40:60 to 90:10.

A prelithiated anode may include a current collector may include a metal oxide layer. Prelithiated anodes may in addition include a lithiated storage layer overlaying the metal oxide layer. The lithiated storage layer may be formed by incorporating lithium into a continuous porous lithium storage layer may include at least 80 atomic % silicon. The lithiated storage layer may include less than 1% by weight of carbon-based binders. The lithiated storage layer may further include lithium in a range of 1% to 90% of a theoretical lithium storage capacity of the continuous porous lithium storage layer. Batteries may include the prelithiated anode.

A negative electrode for nonaqueous electrolyte secondary batteries is provided with: a negative electrode current collector; a first negative electrode mix layer arranged on a surface of the negative electrode current collector; and a second negative electrode mix layer arranged on a surface of the first negative electrode mix layer. The first negative electrode mix layer contains a first carbon material having a true density of 2.1 g/cm.sup.3 to 2.3 g/cm.sup.3, the second negative electrode mix layer contains a second carbon material having a true density of 1.5 g/cm.sup.3 to 2.0 g/cm.sup.3, the inter-particle porosity of the second carbon material in the second negative electrode mix layer is larger than that of the first carbon material in the first negative electrode mix layer, and the ratio of the mass of the first negative electrode mix layer to that of the second negative electrode mix layer is 95:5 to 80:20.

A method of manufacturing a negative electrode includes providing a negative electrode roll on which a negative electrode structure including a negative electrode current collector, a first negative electrode active material layer formed on one side of the negative electrode current collector, and a second negative electrode active material layer formed on the other side of the negative electrode current collector is wound, preparing a pre-lithiation bath including an impregnation section and a pre-lithiation section and containing a pre-lithiation solution, unwinding the negative electrode structure, moving the negative electrode structure to the impregnation section, and impregnating the negative electrode structure with the pre-lithiation solution; and pre-lithiating the negative electrode structure by moving the same from the impregnation section to the pre-lithiation section. The pre-lithiation is carried out by alternately electrochemically charging the first negative electrode active material layer and the second negative electrode active material layer in the pre-lithiation section.

A lithium-ion battery anode material containing surface-coated disordered rocksalt lithium vanadium oxide is disclosed. The surface coating contains a species selected from the group consisting of carbon, a metal oxide, a metalloid oxide, a metal fluoride, a metalloid fluoride, a metal phosphate, a metalloid phosphate, and combinations thereof. Materials, designs, synthesis methods, and devices related to fast-charging lithium-ion batteries are provided. This invention fills a technology gap by providing anode materials with disordered rocksalt lithium vanadium oxides to achieve fast charging in 10 minutes or less, greater than 200 W.Math.h/kg energy density, a lifetime of at least 10,000 cycles, and improved battery safety. Methods of making and using the optionally surface-coated disordered rocksalt lithium vanadium oxide are disclosed. Many experimental examples are included, demonstrating several remarkable attributes of this battery technology.

A lithium secondary battery which includes an electrode assembly in which a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction, a battery can in which the electrode assembly is accommodated, and a sealing body which seals an open end of the battery can. The positive electrode plate includes positive electrode active material comprising single particles, quasi-single particles, or a combination thereof, and the positive electrode active material has D.sub.min of 1.0 μm or more.

Disclosed is a lithium secondary battery including: an electrode assembly in which a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction; a battery can in which the electrode assembly is accommodated; and a sealing body which seals an open end of the battery can. The positive electrode plate includes a positive electrode active material, and the positive electrode active material includes single particles or quasi-single particles, having an average particle diameter D.sub.50 of 5 μm or less.

A negative electrode material and a preparation method therefor, and a lithium ion battery are provided. The negative electrode material comprises nanometer silicon, a silicon oxide, and crystalline Li.sub.2Si.sub.2O.sub.5, wherein the average grain size is Li.sub.2Si.sub.2O.sub.5 is lower than 20 nm. The preparation method comprises: performing heat treatment on a silicon oxide material under a protective atmosphere or vacuum to obtain a silicon oxide material subjected to heat treatment and mixing the heat-treated silicon oxide material with a lithium source under the protective atmosphere or vacuum, and performing sintering to obtain a negative electrode material, the negative electrode material comprising the nanometer silicon, the silicon oxide, and the crystalline Li.sub.2Si.sub.2O.sub.5