Abstract: The present invention relates to a silicon-carbon-based composite negative electrode active material, and a negative electrode for a secondary battery and a lithium secondary battery including the same, and particularly to a silicon-carbon-based composite negative electrode active material, in which physical stability is improved by including a carbon-based core capable of intercalating and deintercalating lithium ions and at least one silicon particle included in the carbon-based core and disposed in the form of being distributed in an outer portion of the carbon-based core, and a negative electrode for a secondary battery and a lithium secondary battery in which life characteristics are improved by including the same.

Abstract: A method of preparing a lithium metal oxide having a nickel oxide layer formed on a surface thereof includes (1) complexing a nickel precursor onto a surface of a lithium metal oxide; and (2) calcining, through a heat treatment, the lithium metal oxide—the surface of which is complexed with the nickel precursor—obtained in step (1).

Abstract: In the case in which a lithium metal is used in order to increase the capacity of a lithium secondary battery, reversibility of charging and discharging is reduced due to dendrite, etc. A lithium metal having LiF deposited thereon exhibits high stability, whereby reversibility of charging and discharging is increased. In addition, in the case in which LiF is deposited, the lithium metal, which is a negative electrode material, is not consumed, and the shape of a lithium metal electrode is not greatly changed.

Abstract: The present invention relates to a negative electrode and a secondary battery including the same, and particularly, to a negative electrode which includes a negative electrode active material layer including first active material particles each in the form of a secondary particle in which a plurality of primary particles are agglomerated; and second active material particles, wherein the second active material particles have an average particle size (D50) equal to or less than an average particle size (D50) of the primary particles, the first active material particle is artificial graphite, and the second active material particle is a graphite-based particle, and a secondary battery, a battery module, and a battery pack including the same.

Abstract: A device and method for controlling discharge, and more particularly, a device and method for controlling discharge for adjusting a final discharge voltage in accordance with a battery to extend the life of the battery.

Abstract: A negative electrode active material for an electrochemical device which has improved quick charging characteristics. The negative electrode active material includes two types of graphite particles having a different particle diameter and shows a bimodal distribution, wherein the ratio of the average particle diameter (D50) of the first graphite particles to the average particle diameter (D50) of the second graphite particles is larger than 1.7.

Abstract: A negative electrode for a lithium secondary battery (and a lithium secondary battery including the same) including: a negative electrode current collector; a first negative electrode mixture layer present on at least one surface of the negative electrode current collector and including a first carbonaceous negative electrode active material, a first polymer binder and a first conductive material; a second negative electrode mixture layer present on a top surface of the first negative electrode mixture layer and including a silicon-based negative electrode active material, a second polymer binder and a second conductive material; and a third negative electrode mixture layer present on a top surface of the second negative electrode mixture layer and including a second carbonaceous negative electrode active material, a third polymer binder and a third conductive material.

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: The present invention relates to a negative electrode active material including a secondary particle in which primary particles are aggregated, wherein the primary particle includes: a core including one or more of silicon and a silicon compound; and a surface layer which is disposed on a surface of the core and contains carbon, wherein an average particle size D50 of the core is in a range of 0.5 ?m to 20 ?m, a method of preparing the same, an electrode including the same, and a lithium secondary battery including the same.

Abstract: Provided is a metal mesh foil for a current collector of a lithium secondary battery having a hydrophobic deposition layer formed on a surface thereof, wherein the hydrophobic deposition layer is a deposition layer, in which a hydrophobic material is deposited, and has a thickness of 1 ? to 100 ?.

Abstract: A method for pre-lithiation of a negative electrode and a negative electrode formed by the method, the method including forming a mixture of inorganic material powder and molten lithium, forming a lithium metal-inorganic material composite ribbon, rolling the ribbon into a film and bonding the lithium metal-inorganic material composite film on a surface of a negative electrode to form a lithium metal-inorganic material composite layer on the surface of the negative electrode. This method reduces the deterioration of lithium during application of a mixture slurry and a negative electrode for a secondary battery, manufactured by the method for pre-lithiation, has improved initial irreversibility, and a secondary battery manufactured using such a negative electrode has excellent charging and discharging efficiency.

Abstract: A ciphertext comparison method uses homomorphic encryption. An apparatus performs the ciphertext comparison method using the homomorphic encryption. The ciphertext comparison method using homomorphic encryption includes acquiring a first ciphertext obtained by encrypting first real-number data using a homomorphic evaluation algorithm and a second ciphertext obtained by encrypting second real-number data using the homomorphic evaluation algorithm, and generating a ciphertext for a result for comparison in size between the first real-number data and the second real-number data using homomorphic evaluation for the first ciphertext, the second ciphertext, and an approximation function for approximating a signum function.

Abstract: Provided are a negative electrode active material for a lithium secondary battery and a method of preparing the same, wherein since the negative electrode active material includes porous polycrystalline silicon and the porous polycrystalline silicon includes pores disposed at grain boundaries, the negative electrode active material may exhibit a buffering action by internally absorbing changes in volume of the active material during charge and discharge. As a result, lifetime characteristics of a negative electrode and a battery may be improved.

Abstract: An apparatus may perform encryption and/or decryption. An encryption method includes generating a public key share of a user, receiving public key shares of one or more other users from terminals of the one or more other users, generating a public key using the public key share of the user and the public key shares of the one or more other users, and encrypting plaintext using the public key.

Abstract: The present disclosure relates to a negative electrode for a secondary battery and a manufacturing method thereof, the negative electrode including a negative electrode current collector and a lithium metal. The present disclosure provides a negative electrode for a secondary battery including a negative electrode current collector; a lithium metal layer having a fine pattern formed on the negative electrode collector; and a protective layer formed along the surface of the lithium metal layer having the fine pattern, and a method for forming a lithium metal layer having a fine pattern formed thereon and the protective layer. In the negative electrode for a secondary battery according to the present disclosure, effective current density may be reduced and battery capacity may be maximized by forming a fine pattern on a surface of a lithium metal included in a negative electrode to increase an electrode specific surface area.

Abstract: The present invention relates to a negative electrode active material for a lithium secondary battery, which comprises graphite having an alkali carbonate layer formed on a surface thereof, wherein the graphite has an ID/IG ratio of 0.05 to 0.3 in Raman spectroscopy, and a method of preparing the same, wherein, since the negative electrode active material for a lithium secondary battery of the present invention includes the graphite having an alkali carbonate layer formed on the surface thereof, the alkali carbonate layer contributes to the formation of a stable solid electrolyte interface (SEI) to reduce a side reaction with an electrolyte solution including propylene carbonate. Thus, since low-temperature performance and initial efficiency of the lithium secondary battery may be improved, the negative electrode active material for a lithium secondary battery of the present invention is suitable for the preparation of the lithium secondary battery.

Abstract: A negative electrode active material including silicon-based active material particles each including a core including SiOx, wherein 0?x?2, and a coating layer present on the core. Also, a negative electrode active material in which the coating layer is any one of a carbon coating layer or a polymer coating layer, and the coating layer includes a fluorinated material including at least one of an alkali metal or an alkaline earth metal.

Abstract: The present invention relates to a method of manufacturing a negative electrode and a negative electrode manufactured using the method. According to the present invention, negative electrode samples are fabricated to have different electrode densities, and then, in a negative electrode expansion curve of each negative electrode sample according to the 1st charging, when a change in slopes of tangents to the negative electrode expansion curve at an initial state of charge (SOC) of less than 50%, at which the expansion curve increases, satisfies a particular value, a secondary battery manufactured including a negative electrode having the electrode density may exhibit excellent lifespan characteristics and excellent initial efficiency for the corresponding active material.

Abstract: A method for manufacturing a lithium secondary battery including a pre-lithiated negative electrode. A composite of lithium and a negative electrode active material is formed through a lamination process which is a process of manufacturing a battery. In the case of the lithium secondary battery to which the negative electrode having the composite formed by lithium and the negative electrode active material is applied, when the battery starts to operate, the negative electrode active material is pre-lithiated, and thus the charging/discharging process proceeds in the state where the lithium alloy is already formed on the negative electrode, thereby showing an effect of reducing initial irreversible phases.

Abstract: A negative electrode including a lithium metal layer, a lithium nitride thin film layer formed on at least one surface of the lithium metal layer, and a carbon-based thin film layer formed on the lithium nitride thin film layer, a method for preparing the same, and a lithium secondary battery including the same. A lithium nitride thin film layer and a carbon-based thin film layer formed on a lithium metal layer obtains current density distribution uniformly by blocking side reactions caused by a direct contact between the lithium metal layer and an electrolyte as well as increasing a specific surface area of a negative electrode, and enhances cycle performance and reduces an overvoltage by suppressing lithium dendrite formation to improve electrochemical performance of a lithium secondary battery.