Abstract: The present invention relates to: a negative electrode active material including silicon-based composite particles containing SiOx (0<x<2) and a MgSiO3 phase, wherein the MgSiO3 phase includes a first MgSiO3 phase having an enstatite structure and a second MgSiO3 phase having a clinoenstatite structure at a weight ratio of 1:1 to 1:5; a negative electrode including the same; and a secondary battery including the negative electrode.

Abstract: Provided is a negative electrode active material for a lithium secondary battery which includes: a silicon-silicon oxide-magnesium silicate composite comprising a silicon oxide (SiOx, 0<x?2) matrix; and silicon (Si) crystal grains, MgSiO3 crystal grains and Mg2SiO4 crystal grains present in the silicon oxide matrix, wherein the MgSiO3 crystal grains have a crystal size of 5-30 nm and the Mg2SiO4 crystal grains have a crystal size of 20-100 nm in the silicon-silicon oxide-magnesium silicate composite, and the content ratio of MgSiO3 crystal grains to Mg2SiO4 crystal grains is 2:1-1:1 on the weight basis. A method for preparing the negative electrode active material for a lithium secondary battery is also provided.

Abstract: A composite negative electrode active material, which includes: a silicon-based core particle; an outer carbon coating layer positioned on a surface of the silicon-based core particle; first single-walled carbon nanotubes in contact with the outer carbon coating layer, wherein the first single-walled carbon nanotubes protrude from the outer carbon coating layer; a conductive structure spaced apart from the outer carbon coating layer, wherein the conductive structure includes at least one second single-walled carbon nanotubes; and a crosslinking material bonded to the first single-walled carbon nanotube and at least one of the second single-walled carbon nanotubes. The at least one of the second single-walled carbon nanotubes is crosslinked with the first single-walled carbon nanotube by the crosslinking material, and wherein the conductive structure and the first single-walled carbon nanotube are connected to each other.

Abstract: A negative electrode and lithium secondary battery including the same. The negative electrode includes: a current collector; and a negative electrode active material layer on at least one surface of the current collector. The negative electrode active material layer includes 1) a negative electrode active material including a Mg-containing silicon oxide particles, and a graphene coating layer surrounding the surface of the Mg-containing silicon oxide particles, 2) a conductive material including single-walled carbon nanotubes (SWCNT), and 3) a binder. The graphene contained in the graphene coating layer has a D/G band intensity ratio of 0.8 to 1.5, and the D/G band intensity ratio of the graphene is defined as an average value of the ratio of the maximum peak intensity of D band at 1360±50 cm?1 based on the maximum peak intensity of G band at 1580±50 cm?1, as determined by Raman spectroscopy of the graphene.

Abstract: A negative electrode and a lithium secondary battery including the same. The negative electrode includes a current collector; and a negative electrode active material layer on at least one surface of the current collector. The negative electrode active material layer includes 1) a negative electrode active material including a Mg-containing silicon oxide, a carbon coating layer surrounding the surface of the Mg-containing silicon oxide and a graphene coating layer surrounding the surface of the carbon coating layer, 2) a conductive material including single-walled carbon nanotubes (SWCNTs), and 3) a binder. The graphene has a D/G band intensity ratio of 0.8 to 1.5. The D/G band intensity ratio is defined as an average value of the ratio of the maximum peak intensity of D band at 1360 ± 50 cm-1 based on the maximum peak intensity of G band at 1580 ± 50 cm-1, as determined by Raman spectroscopy of graphene.

Abstract: A negative electrode and a lithium secondary battery including the negative electrode. The negative electrode includes a current collector; and a negative electrode active material layer on at least one surface of the current collector. The negative electrode active material layer includes 1) a negative electrode active material including a plurality of Mg-containing silicon oxide, 2) a conductive material including a plurality of graphene and single-walled carbon nanotubes, and 3) a binder. The single-walled carbon nanotubes interconnect the Mg-containing silicon oxide through a linear contact, and the single-walled carbon nanotubes are interconnected by the graphene. The graphene has a D/G band intensity ratio of 0.8 to 1.5, and is an average value of the ratio of the maximum peak intensity of D band at 1360 ± 50 cm-1 to the maximum peak intensity of G band at 1580 ± 50 cm-1, as determined by Raman spectroscopy of graphene.

Abstract: A negative electrode active material which includes a core including SiOx (0<x<2), a shell disposed on the core and includes lithium silicate, and a coating layer disposed on the shell and includes carbon nanotubes. Also, a method of preparing a negative electrode active material as well as a negative electrode and a battery including the same.

Abstract: The present invention relates to a silicon-carbon composite negative electrode active material, a negative electrode including the same, and a secondary battery, wherein the silicon-carbon composite negative electrode active material includes a core containing SiOx (0?X<2), a carbon layer covering at least a portion of the surface of the core, a carbon nanotube structure positioned on the carbon layer, and a polyvinylidene fluoride coating at least a portion of the carbon nanotube structure, wherein the carbon nanotube structure has a structure formed by arranging and bonding 2 to 5,000 single-walled carbon nanotube units side by side, and a portion of the carbon nanotube structure is bonded to the carbon layer.

Abstract: A negative electrode active material including a core, an intermediate layer on a surface of the core, and a shell layer on a surface of the intermediate layer, wherein the core includes a silicon oxide of SiOx (0<x<2); the intermediate layer includes a lithium silicate, the shell layer includes lithium fluoride (LiF) and the intermediate layer is present in an amount of 5 wt %-15 wt % based on a total weight of the negative electrode active material. Also, a method for preparing the negative electrode active material, and a negative electrode and lithium secondary battery including the same. The negative electrode active material provides excellent initial efficiency and life characteristics.

Abstract: The present invention relates to: a negative electrode active material including silicon-based composite particles containing SiOx (0<x<2) and a MgSiO3 phase, wherein the MgSiO3 phase includes a first MgSiO3 phase having an enstatite structure and a second MgSiO3 phase having a clinoenstatite structure at a weight ratio of 1:1 to 1:5; a negative electrode including the same; and a secondary battery including the negative electrode.

Abstract: The present invention relates to a method of preparing a negative electrode active material which includes forming a mixture by mixing Li2O and SiOx(0<x<2) particles including SiO2, forming a reaction product by performing a heat treatment on the mixture at 400° C. to 600° C., and removing a portion of lithium silicate in the reaction product by washing the reaction product.

Abstract: Disclosed is a composite negative electrode active material comprising silicon-based core particles, an outer carbon coating layer present on the silicon-based core particles, and single-walled carbon nanotubes, wherein the single-walled carbon nanotubes are in contact with the outer carbon coating layer and comprise a body partially spaced apart from the outer carbon coating layer, and the outer carbon coating layer comprises oxygen in an amount of 35 wt % to 55 wt % therein.

Abstract: A negative electrode active material including a silicon-carbon-based particle, the silicon-carbon-based particle having a SiCx matrix and boron doped in the SiCx matrix, wherein x of the SiCx matrix is 0.3 or more and less than 0.6.

Abstract: A composite negative electrode active material, which includes: a silicon-based core particle; an outer carbon coating layer positioned on a surface of the silicon-based core particle; first single-walled carbon nanotubes in contact with the outer carbon coating layer, wherein the first single-walled carbon nanotubes protrude from the outer carbon coating layer; a conductive structure spaced apart from the outer carbon coating layer, wherein the conductive structure includes at least one second single-walled carbon nanotubes; and a crosslinking material bonded to the first single-walled carbon nanotube and at least one of the second single-walled carbon nanotubes. The at least one of the second single-walled carbon nanotubes is crosslinked with the first single-walled carbon nanotube by the crosslinking material, and wherein the conductive structure and the first single-walled carbon nanotube are connected to each other.

Abstract: The present invention provides a negative electrode which comprises: a negative electrode current collector; and a negative electrode active material layer formed on the negative electrode current collector and comprising a negative electrode active material containing a silicon-based active material and a carbon-based active material, a binder, and single-walled carbon nanotube aggregates. The single-walled carbon nanotube aggregates are comprised at 0.05 parts by weight to 0.37 parts by weight based on 100 parts by weight of the silicon-based active material in the negative electrode active material layer.

Abstract: A negative electrode active material including a core, an intermediate layer on a surface of the core, and a shell layer on a surface of the intermediate layer, wherein the core includes a silicon oxide of SiOx (0<x<2); the intermediate layer includes a lithium silicate, the shell layer includes lithium fluoride (LiF) and the intermediate layer is present in an amount of 5 wt %-15 wt % based on a total weight of the negative electrode active material. Also, a method for preparing the negative electrode active material, and a negative electrode and lithium secondary battery including the same. The negative electrode active material provides excellent initial efficiency and life characteristics.

Abstract: A negative electrode active material which includes a secondary particle including first primary particles, wherein the first primary particle includes a core including SiOx, wherein 0?x<2, an intermediate layer which covers at least a portion of a surface of the core and includes silicon nitride, silicon oxynitride, or a mixture thereof, and a carbon coating layer which covers at least a portion of the intermediate layer and includes nitrogen-doped carbon, and a negative electrode and a lithium secondary battery which include the same.

Abstract: A negative electrode and a lithium secondary battery include the negative electrode, wherein the negative electrode includes a metal current collector and a negative electrode active material layer including a negative electrode active material and metal nanowires and formed on the metal current collector. The negative electrode active material includes a silicon-based active material and a carbon-based active material, and the metal nanowires include one or more metals selected from the group consisting of copper, gold, nickel, cobalt, and silver.

Abstract: A negative electrode active material including a core, an intermediate layer on a surface of the core, and a shell layer on a surface of the intermediate layer, wherein the core includes a silicon oxide of SiOx (0<x<2); the intermediate layer includes a lithium silicate, the shell layer includes lithium fluoride (LiF) and the intermediate layer is present in an amount of 5 wt %-15 wt % based on a total weight of the negative electrode active material. Also, a method for preparing the negative electrode active material, and a negative electrode and lithium secondary battery including the same. The negative electrode active material provides excellent initial efficiency and life characteristics.

Abstract: The present invention relates to a method of preparing a positive electrode for a secondary battery, which includes preparing a positive electrode by forming a positive electrode active material layer including a positive electrode active material, a conductive agent, and a binder on a positive electrode collector, impregnating the positive electrode in a sacrificial salt solution including a sacrificial salt additive, and, after the impregnating of the positive electrode in the sacrificial salt solution, drying the positive electrode to fill pores of the positive electrode active material layer with the sacrificial salt additive, and a positive electrode for a secondary battery prepared thereby.