A preparation method of a composite anode material of micrometer-sized carbon-coated silicon and carbon includes: subjecting micrometer-sized silicon particles to a chemical vapor deposition reaction under a gas atmosphere containing carbon to obtain carbon-coated first micrometer-sized silicon particles; dispersing the carbon-coated first micrometer-sized silicon particles in a first mixed solvent to obtain a dispersed solution; adding alkali into the dispersed solution and heating the dispersed solution to obtain carbon-coated second micrometer-sized silicon particles; dispersing the carbon-coated second micrometer-sized silicon particles and graphene oxide in a second mixed solvent that are subjected to a hydrothermal reaction to obtain a composite hydrogel of reduced graphene oxide, silicon, and carbon; and heating the hydrogel to obtain the composite anode material.

A lithium metal composite oxide having a layered structure, including at least lithium and an element X, wherein:the element X is at least one element selected from the group consisting of Co, Mn, Fe, Cu, Ti, Mg, Al, W, Mo, Nb, Zn, Sn, Zr, Ga, V, B, Si, S and P; the lithium metal composite oxide contains single particles and satisfies all of requirements (1) to (5):(1): a volume-based 50% cumulative particle size D.sub.50 of the lithium metal composite oxide is 2 μm or more and 10 μm or less; (2): the single particles have, on at least a part of surfaces thereof, adhered fine particles, with the proviso that a maximum particle size of the adhered fine particles is smaller than a particle size of the single particles; (3): the particle size of the single particles is 0.2 to 1.5 times D.sub.50 of the lithium metal composite oxide; (4): a particle size of the adhered fine particles is 0.01 to 0.1 times the D.sub.50 of the lithium metal composite oxide; and (5): an average number of the adhered fine particles adhered per particle of the single particles is 1 or more and 30 or less as measured with respect to a range observable in an image obtained by scanning electron microscope.

Embodiments of the present invention relate to a cathode active material, a method for manufacturing the same, and a lithium secondary battery including the same.

According to an embodiment, a cathode active material can be provided, the cathode active material comprising: a lithium metal oxide including a core and a shell disposed on a surface of the core; and a coating layer disposed on a surface of the lithium metal oxide, wherein a c value that satisfies Equation 1 and is in a range of 0.3 to 0.7, and the core and the shell have a layered crystalline structure.

c=b/a  [Equation 1]

(in Equation 1, a is a peak at 530 to 533 eV and b is a peak at 528 to 531 eV in an XPS spectrum of the coating layer)

The present disclosure relates to a method of manufacturing an anode active material for a lithium secondary battery, the method including: mixing earth graphite and pitch coke with each other; preparing a raw material by adding and mixing a binder to the mixture; performing heat treatment on the raw material; graphitizing the heat-treated mixture to obtain a core part; immersing the core part in a hard carbon coating solution; and drying the coating solution in which the core part is immersed to obtain an anode active material.

The present exemplary embodiments relate to a positive electrode active material, a manufacturing method thereof, and a lithium secondary battery including the same. A positive active material for a lithium secondary battery according to an exemplary embodiment is a lithium metal oxide particle in the form of secondary particles including a plurality of primary particles: a first coating layer positioned on at least a part of the surface of the primary particle, and a second coating layer positioned over at least a portion of the secondary particle surface, the first coating layer comprising a first niobium compound, the second coating layer comprising the first niobium compound and a second niobium compound having a composition different from the first niobium compound.

A negative electrode for lithium secondary batteries and a method of manufacturing the same are provided. The negative electrode includes a negative electrode current collector and a lithiophilic material formed on at least one surface of the negative electrode current collector, wherein the lithiophilic material is an oxidized product of a coating material coated on the negative electrode current collector and includes at least one of a metal or a metal oxide, and an oxide layer is formed on a surface of the negative electrode current collector having the lithiophilic material formed thereon.

The present invention discloses a method for making lead-carbon electrode sheets, lead-carbon electrode sheets and lead-carbon battery. The method consists of steps of oxidizing lead under low-temperature atmosphere and the oxidized lead is used as interface layer of lead-carbon coupling, and using a specialized ventilation method for the carbon to coat the lead. The interface layer of oxidized lead forms a stable interface between the carbon and the lead. Meanwhile, through controlling pressure and temperature, a multi-porous metal composite is formed and the porosity can be penetration paths for air and liquid when the multi-porous metal composite is applied. The lead-carbon composite is applied as a lead-carbon electrode sheet and is further welded as a lead-carbon electrode sheet of a lead-carbon battery. The lead-carbon battery carrying the lead-carbon electrode demonstrates Coulomb efficiency of 100% without heat loss on an unsaturated charge-discharge condition of high-efficiency charging and high-efficiency discharging.

Disclosed is a method for manufacturing a dry electrode. The method allows determination of the micro-fibrilization degree of a binder resin from the crystallinity of the binder resin. Based on this, the processing conditions of mixed powder for electrode or an electrode film may be controlled. In this manner, it is possible to check and control the processing conditions easily and efficiently. In addition, the method for manufacturing a dry electrode includes a kneading step using a kneader under a low speed and high temperature and pulverization step. Therefore, there is no problem of blocking of a flow path caused by aggregation of the ingredients, which is favorable to mass production.

A method of producing a positive electrode for a non-aqueous electrolyte secondary battery, includes: providing a lithium transition metal composite oxide having a layered structure, having a ratio D.sub.50/D.sub.SEM of 1 or more and 4 or less, and having a certain content of nickel and a certain content of cobalt; bringing the lithium transition metal composite oxide into contact with a cobalt compound to obtain an adhered material; heat-treating the adhered material at a temperature higher than 700° C. and lower than 1100° C. to obtain a heat-treated product; obtaining a positive electrode composition containing the heat-treated product, a conductive auxiliary agent, and a binder; and applying and pressurizing the positive electrode composition onto a collector to form an active material layer having a density of 2.7 g/cm.sup.3 or more and 3.9 g/cm.sup.3 or less on the collector.

The propose method of manufacturing a solid-state lithium battery consists of preparing an anode coated with a solid-state electrolyte precursor and a cathode unit coated with solid-state electrolyte, both precursors containing a predetermined amount of a redundant water. The thus prepared anode unit and cathode unit are pressed to each other through their respective electrolyte precursor layers in a closed chamber at a predetermined elevated temperature and under a predetermined mechanical pressure, whereby an integral pre-final solid-state battery unit is formed. The manufacture of the battery is completed by inserting the prefinal product into a casing that leaves parts of the metal current collectors of the prefinal product exposed for use as a battery anode and a battery cathode.