Abstract: An anode active material for a lithium secondary battery includes a carbon-based particle including pores therein, a silicon-containing coating layer formed at an inside the pores of the carbon-based particle or on a surface of the carbon-based particle, and a carbon coating layer formed on the silicon-containing coating layer. A full width at half maximum (FWHM) of an O1s peak of a surface measured by an X-ray photoelectron spectroscopy (XPS) is 2.0 or more. A lithium secondary battery including the anode active material having improved initial discharge capacity and capacity efficiency is provided.

Abstract: An anode active material for a lithium secondary battery and a lithium secondary battery including the same are provided. The anode active material includes a plurality of composite particles, each composite particle including a silicon-based active material particle including silicon; and a carbon coating layer formed on at least a portion of a surface of the silicon-based active material particle, wherein a relative standard deviation of G/Si peak intensity ratios of a Raman spectrum as defined in Equation 1 measured for each of 50 different composite particles among the plurality of composite particles is 50% or less.

Abstract: An anode active material for a lithium secondary battery and a lithium secondary battery are provided. The anode active material includes a carbon-based particle including pores formed in at least one of an inside of the particle and a surface of the particle and having a pore size of the carbon-based particle is 20 nm or less, and silicon formed at an inside of the pores of the carbon-based particle or on the surface of the carbon-based particle. Silicon has an amorphous structure or a crystallite size of silicon measured by an XRD analysis is 7 nm or less. Difference between volume expansion ratios of carbon and silicon can be reduced to improve life-span property of the secondary battery.

Abstract: A server according to an embodiment includes a processor configured to receive a friend add request for a target account from a user terminal accessed with a user account; based on one of the user account and the target account being a protected account, transmit an approval request for the friend add request to a protector account connected to the protected account; and based on receiving a reply to the approval request from the protector terminal, add the target account to a friend list of the user account.

Abstract: An anode active material for a secondary battery according to an embodiment of the present application includes lithium-silicon composite oxide particle. The lithium-silicon composite oxide particles include at least one selected from the group consisting of Li2SiO3 and Li2Si2O5 and have a phase fraction ratio defined by Equation 1 of 1.0 or less. A content of particles having a diameter of less than 3 ?m is 5 vol % or less based on a total volume of the lithium-silicon composite oxide particles.

Abstract: An anode active material for a secondary battery includes a plurality of composite particles. The composite particles include carbon-based particles containing pores therein. A silicon-containing coating layer is formed inside the pores or on a surface of the carbon-based particles. A surface oxide layer is formed on the silicon-containing coating layer. The surface oxide layer contains silicon oxide. A silicon oxidation number ratio of the composite particle is predefined.

Abstract: An anode active material for a lithium secondary battery and a lithium secondary battery are provided. The anode active material includes a carbon-based particle including pores formed in at least one of an inside of the particle and a surface of the particle and having a pore size of the carbon-based particle is 20 nm or less, and silicon formed at an inside of the pores of the carbon-based particle or on the surface of the carbon-based particle. Silicon has an amorphous structure or a crystallite size of silicon measured by an XRD analysis is 7 nm or less. Difference between volume expansion ratios of carbon and silicon can be reduced to improve life-span property of the secondary battery.

Abstract: A method for a first user terminal to use a messenger service of a group chat room is proposed. The method may include receiving, from a server, invitation information associated with a second user's inviting a first user to the group chat room, and displaying chat room information on the group chat room. The method may also include in response to the second user not being registered as a friend of the first user in the messenger service, displaying information on the second user and an interface for deciding whether to participate in the group chat room. The method may further include acquiring an interaction regarding a decision to participate in the group chat room through the interface, and displaying a message created in the group chat room.

Abstract: According to embodiments of the present invention, there is provided an anode active material for a lithium secondary battery including a silicon oxide which includes a carbon coating layer on a surface thereof and is doped with magnesium. A ratio of peak area at 1303 eV to a sum of a peak area at 1304.5 eV and a peak area at 1303 eV, which appear in a Mg1s spectrum when measuring by X-ray photoelectron spectroscopy (XPS), is 60% or less.

Abstract: An anode active material for a lithium secondary and a lithium second battery including the same are provided. The anode active material includes a plurality of carbon-based particles containing one or more pores therein, and a silicon-containing coating formed inside the pores and/or on a surface of each of the carbon-based particles. A relative standard deviation of D/G peak intensity ratios of a Raman spectrum measured for 50 different carbon-based particles among the plurality of carbon-based particles is 10% or less.

Abstract: Provided is a negative electrode active material for a secondary battery including a core-shell composite including: a core including a silicon oxide (SiOx, 0<x?2) and a metal silicate in at least a part of the silicon oxide; and a shell including a metal-substituted organic compound, wherein the metal of the metal silicate and the substituted metal of the organic compound are independent of each other, wherein each of the metal of the metal silicate and the substituted metal of the organic compound includes an alkali metal or an alkaline earth metal.

Abstract: Provided are a lithium-doped silicon-based negative electrode active material, a method of producing the same, and a negative electrode and a lithium secondary battery including the same. According to an exemplary embodiment of the present invention, a method of producing a negative electrode active material for a secondary battery including: a) a metal doping process of mixing a silicon-based material and a metal precursor and performing a heat treatment to dope the silicon-based material with a metal; and b) an acid gas treatment process of treating the metal-doped silicon-based material in an acid gas atmosphere to remove residual metal may be provided.

Abstract: An anode active material and a secondary battery including the anode active material are disclosed. In an implementation, an anode active material for a secondary battery includes a plurality of composite active material particles, each composite active material particle containing a first active material that includes silicon and a second active material that includes carbon, and a carbon coating covering at least a portion of a surface of at least one of the plurality of composite active material particles. The anode active material has a volume-based particle size distribution represented as a ratio D10/D50 ranging from 0.40 to 0.75 and a ratio Dmin/D50 ranging from 0.3 to 1, wherein D10 indicates a particle diameter corresponding to a volume fraction of 10%, D50 indicates a particle diameter corresponding to a volume fraction of 50%, and Dmin indicates a minimum particle diameter.

Abstract: A user terminal according to an embodiment may include a processor configured to: based on accessing an instant messaging server with a user account and the user account being a general account, display a general interface for a plurality of services provided to the general account; and based on the user account being a protected account, display a protected interface in which at least some of the plurality of services provided to the general account is restricted.

Abstract: According to embodiments of the present invention, there is provided an anode active material for a lithium secondary battery including a silicon oxide which includes a carbon coating layer on a surface thereof and is doped with magnesium. A ratio of peak area at 1303 eV to a sum of a peak area at 1304.5 eV and a peak area at 1303 eV, which appear in a Mg1s spectrum when measuring by X-ray photoelectron spectroscopy (XPS), is 60% or less.

Abstract: The present disclosure provides a core-shell particle including a core including a porous substrate and a flame retardant, and a shell including a thermoplastic polymer and covering the core, and a secondary battery, a module, and a device including the same.

Abstract: An anode active material for a secondary battery according to an embodiment of the present invention includes a carbon-based particle containing pores, a silicon-containing coating layer formed at an inside of the pores or on a surface of the carbon-based particle, and a carbon coating formed on the silicon-containing coating layer. A ratio of a peak intensity (ID) of a D band relative to a peak intensity (IG) of a G band in a Raman spectrum of the carbon coating is 1.65 or less.

Abstract: An anode for a lithium secondary battery includes an anode current collector, a first anode active material layer formed on at least one surface of the anode current collector and including a silicon-based active material and a graphite-based active material, and a second anode active material layer formed on the first anode active material layer and including a porous structure as an active material. The porous structure includes carbon-based particles including pores, and a silicon-containing coating formed at an inside of the pores of the carbon-based particles or on the surface of the carbon-based particles.

Abstract: Provided is a negative electrode for a secondary battery satisfying the following Relation 1: [Relation 1] (V1?V2)/V1*100?45% wherein V1 is a volume fraction (vol %) of silicon-based active material particles having a gray scale value of 30,000 or more in an XRM measurement on a negative electrode in a fully discharged state after formation, and V2 is a volume fraction (vol %) of silicon-based active material particles having a gray scale value of 30,000 or more in an XRM measurement on a negative electrode in a fully charged state after 500 cycles of charging and discharging.

Abstract: An anode active material for a lithium secondary battery and a lithium secondary battery are provided. The anode active material includes a carbon-based particle including pores formed in at least one of an inside of the particle and a surface of the particle and having a pore size of the carbon-based particle is 20 nm or less, and silicon formed at an inside of the pores of the carbon-based particle or on the surface of the carbon-based particle. A peak intensity ratio in a Raman spectrum of silicon defined as I(515)/I(480) is 1.2 or less. Difference between volume expansion ratios of carbon and silicon can be reduced to improve life-span property of the secondary battery.