Abstract: Provided herein are a negative electrode and a secondary battery including the same. In particular, the negative electrode includes: a current collector; a first active material layer including first active material particles and disposed on the current collector; and a second active material layer including second active material particles and disposed on the first active material layer, in which a lithium ion diffusion rate of the second active material particles is two to three times that of the first active material particles.

Abstract: A method of preparing an electrode for a secondary battery, including: (i) a process of preparing a current collector in which through-pores or holes are formed and an electrode slurry containing an electrode active material; (ii) a process of bringing a shielding film into close contact with one surface of the current collector to shield pores or holes on the one surface of the current collector; (iii) a process of coating the electrode slurry on the other surface of the current collector to which the shielding film is not attached, and primarily drying to prepare an interim electrode; (iv) a process of removing the shielding film from the interim electrode; and (v) a process of secondarily drying the interim electrode to prepare the electrode.

Abstract: An electrode mixture of the present invention comprises: an electrode active material; a binder; and a conductive material. When a cross-section of the electrode mixture is imaged such that a pixel filled 100% with a conductive material among a plurality of divided pixels is considered to be a condensed pixel and a value obtained by counting condensed pixels is considered to be the degree of agglomeration, the degree of agglomeration of a conductive material in the electrode mixture in the depth direction of the electrode mixture has a standard deviation less than 3.0. The electrode mixture as described above includes a conductive material uniformly distributed therein and thus has low electrode resistance. Therefore, the electrode mixture can improve output and lifespan properties of a lithium secondary battery to which the electrode mixture has been applied.

Abstract: Disclosed herein is an electrode for a secondary battery including an electrode mixture layer including an electrode active material on one surface or both surfaces of a current collector, wherein the electrode mixture layer includes a plurality of fine holes recessed toward the current collector from a vertical cross-sectional surface, and each of the fine holes is a horn-shaped hole whose diameter is gradually decreased from the vertical cross-sectional surface toward the current collector in the electrode mixture layer.

Abstract: An electrode mixture of the present invention comprises: an electrode active material; a binder; and a conductive material. When a cross-section of the electrode mixture is imaged such that a pixel filled 100% with a conductive material among a plurality of divided pixels is considered to be a condensed pixel and a value obtained by counting condensed pixels is considered to be the degree of agglomeration, the degree of agglomeration of a conductive material in the electrode mixture in the depth direction of the electrode mixture has a standard deviation less than 3.0. The electrode mixture as described above includes a conductive material uniformly distributed therein and thus has low electrode resistance. Therefore, the electrode mixture can improve output and lifespan properties of a lithium secondary battery to which the electrode mixture has been applied.

Abstract: A secondary battery having improved output characteristics is disclosed. The secondary battery according to the present invention accommodates a cell assembly including a plurality of cells connected in parallel, and an electrolyte together in one package, in which positive electrodes of a plurality of central cells disposed at a central part of the cell assembly have a loading energy density higher than that of positive electrodes of a plurality of side cells disposed at a side part, and the positive electrodes of the central cells have positive electrode material coating layers formed at surfaces thereof, which are thicker than those formed at surfaces of the positive electrodes of the side cells. Preferably, the total resistance of the side cells is lower than the total resistance of the central cells.

Abstract: An electrode mixture of the present invention comprises: an electrode active material; a binder; and a conductive material. When a cross-section of the electrode mixture is imaged such that a pixel filled 100% with a conductive material among a plurality of divided pixels is considered to be a condensed pixel and a value obtained by counting condensed pixels is considered to be the degree of agglomeration, the degree of agglomeration of a conductive material in the electrode mixture in the depth direction of the electrode mixture has a standard deviation less than 3.0. The electrode mixture as described above includes a conductive material uniformly distributed therein and thus has low electrode resistance. Therefore, the electrode mixture can improve output and lifespan properties of a lithium secondary battery to which the electrode mixture has been applied.

Abstract: The present disclosure is intended to design a secondary battery with improved boosting charge performance by estimating reaction in the thickness-wise direction of the electrode, and provides a method or estimating reaction of a secondary battery including (a) preparing a battery cell having a structure of first electrode/separator/reference electrode/separator/second electrode, wherein the second electrode has a structure of upper layer/porous film/lower layer, (b) setting a charging condition to estimate reaction of the battery cell, (c) measuring voltage and current of each of the upper layer, the lower layer and the battery cell while the set charging condition is reached, (d) after the charging condition, measuring an open-circuit voltage of the upper layer, the lower layer and the battery cell, and (e) comparatively analyzing a capacity obtained using the measured current with the measured open-circuit voltage, and a battery cell used for the same.

Abstract: The present invention relates to an electrode for an electrochemical device and a method for manufacturing the same. More specifically, the present invention relates to an electrode for an electrochemical device having excellent electrolyte impregnation and improved battery output and lifecycle properties, and a method for manufacturing the electrode. The electrode according to the present invention enables an electrolyte to easily permeate into the electrode, thereby remarkably improving a lifecycle property or an output property due to high electrolyte impregnation. In addition, the method for manufacturing an electrode, according to the present invention, does not cause the deterioration of porosity of a lower electrode active material monolayer, the deterioration being caused by a step performed during the formation of an upper electrode active material monolayer.

Abstract: Provided are a method of predicting a battery charge limit not to cause lithium (Li)-plating, and a battery charging method and apparatus capable of quickly charging a battery based on the battery charge limit. A battery charge limit prediction method according to the present disclosure includes (a) fabricating a three-electrode cell including a unit cell and a reference electrode, (b) measuring a negative electrode potential (CCV) based on a state of charge (SOC) while charging the three-electrode cell, and (c) determining a point at which the negative electrode potential is not dropped but starts to be constant, as a lithium (Li)-plating occurrence point, and setting the Li-plating occurrence point as a charge limit.

Abstract: The present invention relates to an electrode for a secondary battery having improved safety, a method for manufacturing the electrode, and a secondary battery including the electrode. The secondary battery according to the present invention includes a plurality of apertures that penetrate a current collector and an electrode active material layer in a thickness direction. The electrode may improve safety by preventing or minimizing the occurrence of ignition or explosion when a sharp object such as a nail penetrates into the interior of a battery, thereby improving safety of the battery.

Abstract: Disclosed herein is an electrode for a secondary battery including an electrode mixture layer including an electrode active material on one surface or both surfaces of a current collector, wherein the electrode mixture layer includes a plurality of fine holes recessed toward the current collector from a vertical cross-sectional surface, and each of the fine holes is a horn-shaped hole whose diameter is gradually decreased from the vertical cross-sectional surface toward the current collector in the electrode mixture layer.

Abstract: The present disclosure is intended to design a secondary battery with improved boosting charge performance by estimating reaction in the thickness-wise direction of the electrode, and provides a method or estimating reaction of a secondary battery including (a) preparing a battery cell having a structure of first electrode/separator/reference electrode/separator/second electrode, wherein the second electrode has a structure of upper layer/porous film/lower layer, (b) setting a charging condition to estimate reaction of the battery cell, (c) measuring voltage and current of each of the upper layer, the lower layer and the battery cell while the set charging condition is reached, (d) after the charging condition, measuring an open-circuit voltage of the upper layer, the lower layer and the battery cell, and (e) comparatively analyzing a capacity obtained using the measured current with the measured open-circuit voltage, and a battery cell used for the same.

Abstract: Provided are a method and an apparatus for rapidly charging a battery, such that a battery can be rapidly charged while having an extended lifetime. The method for charging a battery according to the present invention charges a battery by starting from an initial charging rate higher than 1 C, while stepwise decreasing the charging rate, such that a negative electrode potential of the battery does not drop to a level less than or equal to 0V. An occurrence of Li-plating of a negative electrode of the battery can be prevented by the criteria for preventing the negative electrode potential from dropping to a level less than or equal to 0V, thereby providing an effect of rapidly charging the battery while extending the lifetime of the battery.

Abstract: A method of preparing an electrode for a secondary battery, including: (i) a process of preparing a current collector in which through-pores or holes are formed and an electrode slurry containing an electrode active material; (ii) a process of bringing a shielding film into close contact with one surface of the current collector to shield pores or holes on the one surface of the current collector; (iii) a process of coating the electrode slurry on the other surface of the current collector to which the shielding film is not attached, and primarily drying to prepare an interim electrode; (iv) a process of removing the shielding film from the interim electrode; and (v) a process of secondarily drying the interim electrode to prepare the electrode.

Abstract: Provided is a non-destructive method for detecting lithium plating by which lithium plating can be detected in real time in an actual use environment of a secondary battery, a secondary battery charging method and apparatus for charging a secondary battery under the condition in which lithium plating does not occur by using this method, and a secondary battery system for detecting the state of a secondary battery by using this method. The method for detecting lithium plating according to the present disclosure is a method which detects lithium plating in a negative electrode in real time by observing a change in battery voltage as a function of SOC during charging a secondary battery, and determines a point at which a rise speed of the battery voltage slows down as a lithium plating occurrence point.

Abstract: Provided are a method of predicting a battery charge limit not to cause lithium (Li)-plating, and a battery charging method and apparatus capable of quickly charging a battery based on the battery charge limit. A battery charge limit prediction method according to the present disclosure includes (a) fabricating a three-electrode cell including a unit cell and a reference electrode, (b) measuring a negative electrode potential (CCV) based on a state of charge (SOC) while charging the three-electrode cell, and (c) determining a point at which the negative electrode potential is not dropped but starts to be constant, as a lithium (Li)-plating occurrence point, and setting the Li-plating occurrence point as a charge limit.

Abstract: Provided herein are a negative electrode and a secondary battery including the same. In particular, the negative electrode includes: a current collector; a first active material layer including first active material particles and disposed on the current collector; and a second active material layer including second active material particles and disposed on the first active material layer, in which a lithium ion diffusion rate of the second active material particles is two to three times that of the first active material particles.

Abstract: The present disclosure refers to a cathode material composite having improved conductivity, and a cathode and electrochemical device having the cathode material composite. In accordance with one embodiment of the present disclosure, a conductive polymer is positioned on the surface of a shell present in the form of a tetragonal structure in the lithium manganese oxide, thereby enhancing electrical conductivity to be highly involved in reaction around 3V, and providing a conductive path to improve the capacity, life and rate characteristics of an electrochemical device.

Abstract: The present disclosure relates to a positive electrode for a lithium secondary battery including an electrode current collector, and a positive electrode active material layer coated on at least a part of the electrode current collector, wherein the positive electrode active material layer includes a manganese-based positive electrode active material, and a porosity is from 30% to 35%, to improve high-temperature storage characteristics and high-temperature cycle characteristics.