Abstract: Discussed is a secondary battery low-voltage defect determination system, which can include a database unit configured to store existing data on battery manufacturing process conditions, activation process conditions, voltage measurement conditions, and a battery voltage measured after an activation process of a battery, a detection unit configured to detect experimental data on the manufacturing process conditions, the activation process conditions, the voltage measurement conditions, and the battery voltage measured after the activation process of the battery, and a calculation unit configured to calculate target voltage drop correction data based on the existing data stored in the database unit and the experimental data detected by the detection unit.

Abstract: Disclosed herein relates to a method for screening a low-voltage defective battery including: (a) a pre-filtering step of collecting data and removing secondary batteries having an outlier data in real time during an activation process of multiple secondary batteries; (b) a clustering step of clustering based on similar characteristics or records for multiple pre-filtered secondary batteries; (c) a correction step of measuring the amount of voltage drop (?OCV) for each cluster and correcting a dispersion of the amount of voltage drop (?OCV) according to a temperature or a period; and (d) a screening step of screening low-voltage defective batteries based on a corrected dispersion of the amount of voltage drop.

Abstract: An apparatus for inspecting defects of a secondary battery having a pair of pressing jigs which press an outer surface of an electrode or a pouch accommodating the electrode assembly in directions corresponding to each other and on which a plurality of protrusions protrude from pressing surfaces and a measurement unit measuring one or more of current, a voltage, and resistance of the electrode assembly when the electrode assembly is pressed by the plurality of protrusions of the pair of pressing jigs is provided.

Abstract: A simultaneous inspection device of multiple secondary battery cell pouches is provided. The simultaneous inspection device includes a support member installed for support; a movable member installed to face the support member; multiple pressure panels which are installed side by side between the support member and the movable member, and combined so that the gap between them can be adjusted by the back and forth movement of the movable member wherein the secondary battery cell pouches are inserted into each gap; a guide member for guiding the pressing panels to move in the direction necessary for adjusting the gaps; and a pressure driving unit for moving the movable member back and forth to pressurize and pressure-release the secondary battery cell pouch between the pressurizing panels on both sides.

Abstract: A jig pressing-type pressing short-circuiting inspection method includes the steps of: pre-aging battery cells, each of which is manufactured by inserting an electrode assembly in a battery container, injecting an electrolyte into the battery container, and sealing the battery container. The method includes inserting the plurality of battery cells in an active jig; pressing the active jig; and inspecting electric current of the battery cells. The inspection method permits detection of a low-voltage defect of a battery cell in a pre-aging state, which shows a high voltage regulation per capacity, thus greatly reducing the inspection time, and enabling simultaneous inspection of a plurality of battery cells. In addition, a micro-defect occurring in a stack-folding type battery cell can be accurately detected, which is difficult to be detected by the conventional inspection method.

Abstract: A top cap for a secondary battery includes a circumferential area which defines an outer circumferential surface of the top cap, a central area which defines a central portion of the top cap, a connection area which connects the circumferential area to the central area, and a protrusion area which protrudes downward from the circumferential area, the central area, or the connection area. The top cap is assembled with a battery case, an electrode assembly positioned therein, and a through-hole formation member to form a secondary battery, in which at least a portion of the protrusion area of the top cap is positioned within a through-hole of the through-hole formation member.

Abstract: A method for manufacturing a secondary battery includes a formation step for charging an assembled secondary battery to a state of charge (SOC) of 45% to 65%; an aging step for aging the secondary battery for which the formation has been completed; and a low voltage testing step for measuring the change in voltage value, wherein, in the low voltage testing step, a voltage value is measured in an SOC interval of 30% or lower. Since an SEI coating is stably formed in the method for manufacturing a secondary battery, charging time is shortened and thus the secondary battery can be mass-produced. In addition, since a low voltage test is performed in an interval in which the voltage change rate per capacity of a negative electrode is high, a low voltage defect due to non-uniformity of the formation process can be detected in the method for manufacturing the secondary battery.

Abstract: A jig pressing-type pressing short-circuiting inspection method includes the steps of: pre-aging battery cells, each of which is manufactured by inserting an electrode assembly in a battery container, injecting an electrolyte into the battery container, and sealing the battery container. The method includes inserting the plurality of battery cells in an active jig; pressing the active jig; and inspecting electric current of the battery cells. The inspection method permits detection of a low-voltage defect of a battery cell in a pre-aging state, which shows a high voltage regulation per capacity, thus greatly reducing the inspection time, and enabling simultaneous inspection of a plurality of battery cells. In addition, a micro-defect occurring in a stack-folding type battery cell can be accurately detected, which is difficult to be detected by the conventional inspection method.

Abstract: A simultaneous inspection device of multiple secondary battery cell pouches is provided. The simultaneous inspection device includes a support member installed for support; a movable member installed to face the support member; multiple pressure panels which are installed side by side between the support member and the movable member, and combined so that the gap between them can be adjusted by the back and forth movement of the movable member wherein the secondary battery cell pouches are inserted into each gap; a guide member for guiding the pressing panels to move in the direction necessary for adjusting the gaps; and a pressure driving unit for moving the movable member back and forth to pressurize and pressure-release the secondary battery cell pouch between the pressurizing panels on both sides.

Abstract: A top cap for a secondary battery includes a circumferential area which defines an outer circumferential surface of the top cap, a central area which defines a central portion of the top cap, a connection area which connects the circumferential area to the central area, and a protrusion area which protrudes downward from the circumferential area, the central area, or the connection area. The top cap is assembled with a battery case, an electrode assembly positioned therein, and a through-hole formation member to form a secondary battery, in which at least a portion of the protrusion area of the top cap is positioned within a through-hole of the through-hole formation member.

Abstract: An apparatus for inspecting defects of a secondary battery having a pair of pressing jigs which press an outer surface of an electrode or a pouch accommodating the electrode assembly in directions corresponding to each other and on which a plurality of protrusions protrude from pressing surfaces and a measurement unit measuring one or more of current, a voltage, and resistance of the electrode assembly when the electrode assembly is pressed by the plurality of protrusions of the pair of pressing jigs is provided.