Abstract: A water electrolysis device includes an electrolyte correction unit having a diaphragm, the device having an electrolyte correction unit, including a diaphragm, for removing a concentration difference inside an electrolyte, so as to prevent a gas composition in a gas phase area of the water electrolysis device from reaching an explosion limit and, simultaneously, prevent the occurrence of a difference in a liquid level due to a difference in the concentration of the electrolyte even if the electrolyte discharged from an anode chamber and the electrolyte discharged from a cathode chamber are each circulated independently, and thus does not require an additional device for solving same, and can resolve the problem of a reduction in processability according to electrolyte re-injection and operation stabilization.

Abstract: A method of preparing a positive electrode active material having a high ratio of charge and discharge capacity at a charge end voltage of 4.1 V to 4.175 V to charge and discharge capacity at a charge end voltage of 4.2 V to 4.275 V and having an excellent initial charge and discharge capacity is provided.

Abstract: An aspect of the present disclosure provides a power management system including: a power source that includes a power system for providing main power to a load and a renewable energy generation part for providing auxiliary power; a power conversion part that converts a surplus of at least one of the main power and the auxiliary power; a water electrolysis part that includes a water electrolysis device configured to be driven by the surplus converted by the power conversion part, a balance-or-plant (BOP) configured to be driven by a portion branched from the main power, and a hydrogen storage; and a control part that synchronizes power applied to the power conversion part and power applied to the water electrolysis device to exchange direct current (DC) power between the power conversion part and the water electrolysis device.

Abstract: The present disclosure relates to a water electrolysis apparatus including a diaphragm for removing a dissolved gas from an electrolyte. By separating a dissolved gas present in an electrolyte through a diaphragm provided in a gas-liquid separator or an electrolyte circulation line, the water electrolysis apparatus can increase the efficiency of production of the dissolved gas in the electrolyte while preventing a gas composition from reaching an explosive limit in a gas phase region of the water electrolysis apparatus.

Abstract: A positive electrode active material for a secondary battery including: a lithium complex transition metal oxide which contains nickel (Ni) and cobalt (Co), and contains at least one selected from the group consisting of manganese (Mn) and aluminum (Al); and a composite coating portion which is formed on a surface of the lithium complex transition metal oxide is provided. The lithium complex transition metal oxide has a nickel (Ni) content of 65 mol % or more with respect to the total transition metal content, and the composite coating portion contains cobalt (Co) and boron (B), and contains at least one selected from the group consisting of lanthanum (La), titanium (Ti), and aluminum (Al).

Abstract: A method for preparing a positive electrode active material for a secondary battery is provided. The method includes preparing a lithium composite transition metal oxide including nickel, cobalt, and manganese (Mn), wherein the content of the nickel in the total content of the transition metal is 60 mol % or greater. The lithium composite transition metal oxide, MgF2 as a fluorine (F) coating source, and a boron (B) coating source undergoes dry mixing and heat treatment to form a coating portion on the particle surface of the lithium composite transition metal oxide. In addition, a positive electrode active material prepared as described above, is also provided.

Abstract: The present invention relates to a method of preparing a positive electrode active material precursor for a lithium secondary battery in which particle size uniformity and productivity may be improved by using three reactors, a method of preparing a positive electrode active material for a lithium secondary battery by using the above-prepared positive electrode active material precursor for a lithium secondary battery, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the above-prepared positive electrode active material for a lithium secondary battery.

Abstract: A positive electrode active material for a secondary battery including: a lithium complex transition metal oxide which contains nickel (Ni) and cobalt (Co), and contains at least one selected from the group consisting of manganese (Mn) and aluminum (Al); and a composite coating portion which is formed on a surface of the lithium complex transition metal oxide is provided. The lithium complex transition metal oxide has a nickel (Ni) content of 65 mol % or more with respect to the total transition metal content, and the composite coating portion contains cobalt (Co) and boron (B), and contains at least one selected from the group consisting of lanthanum (La), titanium (Ti), and aluminum (Al).

Abstract: The present invention relates to a method of preparing a positive electrode active material precursor for a lithium secondary battery in which particle size uniformity and productivity may be improved by using three reactors, a method of preparing a positive electrode active material for a lithium secondary battery by using the above-prepared positive electrode active material precursor for a lithium secondary battery, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the above-prepared positive electrode active material for a lithium secondary battery.

Abstract: A method of preparing a positive electrode active material includes mixing a lithium raw material and a nickel-containing transition metal hydroxide precursor containing nickel in an amount of 65 mol % or more based on a total number of moles of transition metals and performing a first heat treatment to prepare a nickel-containing lithium transition metal oxide. The method also includes mixing a boron and carbon-containing raw material and a cobalt-containing raw material with the nickel-containing lithium transition metal oxide to form a mixture, and performing a second heat treatment on the mixture to form a coating material including B and Co on a surface of the lithium transition metal oxide. A positive electrode active material prepared by the preparation method is formed, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the positive electrode active material.

Abstract: A positive electrode includes: a positive electrode active material layer formed on a surface of a positive electrode current collector, including two types of positive electrode active materials with different average particle diameters (D50), a conductive material, and a binder; and a carbon nanotube coating layer formed on a surface of the positive electrode active material layer, including carbon nanotubes and a binder: The two types of positive electrode active materials include first positive electrode active material particles which have an average particle diameter (D50) of 8 ?m to 20 ?m and second positive electrode active material particles in the form of a single particle which have a smaller average particle diameter (D50) than the average particle diameter (D50) of the first positive electrode active material particles, and the positive electrode active material layer and the carbon nanotube coating layer are formed in a thickness ratio of 90:10 to 99:1.

Abstract: A positive electrode includes: a positive electrode active material layer formed on a surface of a positive electrode current collector, including two types of positive electrode active materials with different average particle diameters (D50), a conductive material, and a binder; and a carbon-based coating layer formed on a surface of the positive electrode active material layer. The two types of positive electrode active materials are each represented by Chemical Formula 1 below. The carbon-based coating layer includes a sphere-type conductive material and a binder, where the binder is included in an amount of 5 parts by weight or more and less than 10 parts by weight with respect to 100 parts by weight of the carbon-based coating layer. Li1+aNixCoyMzO2 ??[Chemical Formula 1] In Chemical Formula 1, 0?a?0.5, 0<x<1, 0<y<1, 0<z<1, and M is at least one of Mn and Al.

Abstract: A method for preparing a positive electrode active material is provided. The method includes a first step for adding, to a reactor, a reaction solution including a transition metal-containing solution containing at least one among nickel, cobalt, and manganese, an ammonium ion-containing solution, and a basic aqueous solution to form seeds of precursor particles; a second step for preparing carbon-introduced precursor particles by adding a carbon source to the reactor when the precursor particles grow until the average particle diameter (D50) is 30% in size of the average particle diameter (D50) of the finally prepared precursor particles; and a third step for mixing the carbon-introduced precursor particles and a lithium raw material and sintering the mixture at a temperature of 750° C. to 950° C. to prepare positive electrode active material particles.

Abstract: A positive electrode active material is provided, including a lithium transition metal oxide containing nickel (Ni), cobalt (Co), and manganese (Mn), wherein the lithium transition metal oxide has 60 mol % or more nickel (Ni) with respect the total number of moles of transition metal except lithium, and is doped with at least any one doping element selected from the group consisting of B, Zr, Mg, Ti, Sr, W, and Al. The positive electrode active material has an average particle diameter (D50) of 4 ?m to 10 ?m after rolling at a rolling density of 3.0 g/cm3 to 3.3 g/cm3 and has the form of a single particle. A method of preparing the positive electrode active material, a positive electrode including the positive electrode active material, and a lithium secondary battery are also provided.

Abstract: A method for preparing a positive electrode active material for a secondary battery is provided. The method includes preparing a lithium composite transition metal oxide including nickel, cobalt, and manganese, wherein the content of the nickel in the total content of the transition metal is 60 mol % or greater. The lithium composite transition metal oxide, MgF2 as a fluorine (F) coating source, and a boron (B) coating source undergoes dry mixing and heat treatment to form a coating portion on the particle surface of the lithium composite transition metal oxide. In addition, a positive electrode active material prepared as described above, is also provided.

Abstract: The present invention provided a positive electrode active material for a lithium secondary battery including lithium cobalt oxide particles. The lithium cobalt oxide particles include lithium deficient lithium cobalt oxide having Li/Co molar ratio of less than 1, belongs to an Fd-3m space group, and having a cubic crystal structure, in surface of the particle and in a region corresponding to a distance from 0% to less than 100% from the surface of the particle relative to a distance (r) from the surface to the center of the particle. In the positive electrode active material for a lithium secondary battery according to the present invention, the intercalation and deintercalation of lithium at the surface of a particle may be easy, and the output property and rate characteristic may be improved when applied to a battery. Accordingly, good life property and the minimization of gas generation amount may be attained even with large sized positive electrode active material.

Abstract: A positive electrode active material for a lithium secondary battery includes a lithium composite transition metal oxide including transition metals including nickel (Ni), cobalt (Co), and manganese (Mn), and the lithium composite transition metal oxide is doped with doping elements including cobalt (Co) and titanium (Ti). The lithium composite transition metal oxide includes at least one lithium layer and at least one transition metal layer including the transition metals, and the lithium layer and the transition metal layer are alternately arranged. The thickness of the lithium layer ranges from 2.146 ? to 2.182 ?, and the thickness of the transition metal layer ranges from 2.561 ? to 2.595 ?A.

Abstract: The present invention provided a positive electrode active material for a lithium secondary battery including lithium cobalt oxide particles. The lithium cobalt oxide particles include lithium deficient lithium cobalt oxide having Li/Co molar ratio of less than 1, belongs to an Fd-3m space group, and having a cubic crystal structure, in surface of the particle and in a region corresponding to a distance from 0% to less than 100% from the surface of the particle relative to a distance (r) from the surface to the center of the particle. In the positive electrode active material for a lithium secondary battery according to the present invention, the intercalation and deintercalation of lithium at the surface of a particle may be easy, and the output property and rate characteristic may be improved when applied to a battery.

Abstract: Disclosed is a lithium-cobalt based complex oxide represented by Formula 1 below including lithium, cobalt and manganese wherein the lithium-cobalt based complex oxide maintains a crystal structure of a single O3 phase at a state of charge (SOC) of 50% or more based on a theoretical amount: LixCo1-y-zMnyAzO2??(1) wherein 0.95?x?1.15, 0<y?0.3 and 0?z?0.2; and A is at least one element selected the group consisting of Al, Mg, Ti, Zr, Sr, W, Nb, Mo, Ga, and Ni, wherein the at least one element of A is Mg.

Abstract: The present invention relates to positive electrode active material particles and a secondary battery including the same and provides positive electrode active material particles comprising: a core including a first lithium transition metal oxide; and a shell surrounding the core, wherein the shell has a form in which metal oxide particles are embedded in a second lithium transition metal oxide, and at least a part of the metal oxide particles is present by being exposed at a surface of the shell. The positive electrode active material particles according to the present invention prevent a transition metal and an electrolyte from causing a side reaction by exposing a part of a metal oxide, having low reactivity, at a surface of the active materials, thereby improving safety and lifespan. As the electrical conductivity of the active materials becomes lower, excellent stability can be maintained even at high temperature and in battery-breakdown situations.