The present invention provides a silicon-silicon composite oxide-carbon composite, a method for preparing same, and a negative electrode active material for a lithium secondary battery, comprising same. More particularly, the silicon-silicon composite oxide-carbon composite of the present invention has a core-shell structure wherein the core comprises silicon, a silicon oxide compound, and magnesium silicate, and the shell comprises a carbon layer. In addition, by having a specific range of span values through the adjustment of particle size distribution of the composite, when used as a negative electrode active material of a secondary battery, the composite can improve not only the capacity of the secondary battery but also the cycle characteristics and initial efficiency thereof.

The present invention provides a silicon-silicon composite oxide-carbon composite, a method for preparing same, and a negative electrode active material for a lithium secondary battery, comprising same. More particularly, the silicon-silicon composite oxide-carbon composite of the present invention has a core-shell structure wherein the core comprises silicon, a silicon oxide compound, and magnesium silicate, and the shell comprises a carbon layer. In addition, by having a specific range of span values through the adjustment of particle size distribution of the composite, when used as a negative electrode active material of a secondary battery, the composite can improve not only the capacity of the secondary battery but also the cycle characteristics and initial efficiency thereof.

A positive electrode for a secondary battery including a positive electrode current collector, and a positive electrode mixture layer containing a positive electrode active material and disposed on a surface of the positive electrode current collector. The positive electrode mixture layer contains a first positive electrode active material having a compressive strength of 400 MPa or more, and a second positive electrode active material having a compressive strength of 250 MPa or less. When the positive electrode mixture layer is divided into a first region and a second region having the same thickness, the first positive electrode active material is contained more in the first region than in the second region, and the second positive electrode active material is contained more in the second region than in the first region.

The present disclosure relates to a positive electrode slurry for a lithium-sulfur battery including a positive electrode active material, an electrically conductive material, a binder and a solvent, where the ratio of the average particle diameter (D.sub.50) of the positive electrode active material and the positive electrode slurry is 1.5 or less, and the phase angle at 1 Hz of the positive electrode slurry is 50° or more. The positive electrode slurry for the lithium-sulfur battery of the present disclosure exhibits excellent flowability even while having a high solid content, thereby making it possible to manufacture a positive electrode for a lithium-sulfur battery with excellent electrochemical properties and improving the productivity and economic feasibility of the manufacturing process of the positive electrode for the lithium-sulfur battery.

The present invention relates to a battery cell with improved safety and a method of manufacturing the same, and more particularly a battery cell configured such that an electrode assembly including a positive electrode (200) and a negative electrode (300) located so as to be opposite each other in the state in which a separator (400) is interposed therebetween is received in a cell case (100), wherein the positive electrode (200) includes a positive electrode plate (210) and a positive electrode active material layer (220) provided on one surface and/or the other surface of the positive electrode plate (210), the negative electrode (300) includes a negative electrode plate (310) and a negative electrode active material layer (320) provided on one surface and/or the other surface of the negative electrode plate (310), the positive electrode active material layer (220) includes a first flat portion (221) and a first inclined portion (222) provided at each of opposite sides of the first flat portion (221), and the negative electrode active material layer (320) includes a second flat portion (321) and a second inclined portion (322) provided at each of opposite sides of the second flat portion (321) and a method of manufacturing the same.

A cathode structure for a battery includes a substrate having an electrically conductive surface and an electrode deposited onto the electrically conductive surface. The electrode is made of two or more electrode materials, including (i) one or more active materials, and (ii) specified weight percentage ranges of multi-walled carbon nanotubes (“MWCNTs”), or milled carbon fibers (“MCFs”), or a mixture of MWCNTs and MCFs. Using the specified weight percentage ranges, the electrode may be produced with a thickness of greater than 120 μm. Also disclosed are a slurry formulation for producing thick electrodes for a battery, and a method of fabricating a cathode structure for a battery.

Provided is a lithium-containing oxide precursor solution for coating an electrode active material that is capable of improving the coverage of a coating layer that is formed by applying the lithium-containing oxide precursor solution to the surface of powder of the electrode active material and king it, and that is easy to handle in a normal atmosphere because a solution composed mainly of water is used as a solvent. The lithium-containing oxide precursor solution for coating an electrode active material includes Li in an amount of 0.1 mass % or more and 5.0 mass % or less, at least one element selected from Nb, F, Fe, P, Ta, V, Ge, B, Al, Ti, Si, W, Zr, Mo, S, Cl, Br, and I in an amount of 0.05 mass % or more and 35 mass % or less, and water in an amount of 60 mass % or more and 98.4 mass % or less. The value of absorbance of the solution at a wavelength of 660 nm is 0.1 or less, and the value of surface energy thereof is 72 mN/m or less.

The present disclosure belongs to the technical field of lithium battery cathode materials, and discloses a preparation method of multiple carbon-coated high-compaction lithium iron manganese phosphate, comprising the following steps: (1) synthesizing a carbon and vanadium co-doped ferromanganese phosphate precursor through a co-precipitation method, sintering, and removing crystal water to obtain an anhydrous ferromanganese phosphate precursor; (2) adding lithium phosphate, a supplemental phosphorus source, an organic carbon source, a dopant and deionized water, and performing ball milling, wet sanding, spray drying and sintering to obtain an intermediate material; and (3) adding deionized water and the organic carbon source, then performing ball milling, sanding, spray drying, sintering and air jet pulverization to obtain multiple carbon-coated high-compaction lithium iron manganese phosphate.

An improved structure of nano-scaled and nanostructured Si particles is provided for use as anode material for lithium ion batteries. The Si particles are prepared as a composite coated with MgO and metallurgically bonded over a conductive refractory valve metal support structure.

A natural graphite-based modified composite material, a preparation method therefor, and a lithium ion battery comprising the modified composite material. The natural graphite-based modified composite material comprises natural graphite and non-graphitized carbon coated on the inner and outer surfaces of the natural graphite. The preparation method comprises: (1) subjecting spherical natural graphite to isotropic treatment; (2) performing granularity control and shaping treatment; (3) subjecting the inner surface and the outer surface of the material obtained in step (2) to simultaneous modification; and (4) performing carbonization, so as to obtain a natural graphite-based modified composite material.