Battery pack and diagnostic method thereof

Abstract

A battery pack according to an embodiment disclosed in the present document comprises: a soft pack covering a positive electrode material and a negative electrode material; a battery cell including a first terminal and a second terminal; a connection unit including a transistor connecting the soft package and the first terminal; and a controller that measures an inrush current flowing into the connection unit and diagnoses a state of the battery cell based on the inrush current.

Description

TECHNICAL FIELD

[0001] CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0087011, filed on July 5, 2023, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0004] Embodiments disclosed herein relate to a battery pack and a diagnosis method thereof. BACKGROUND

[0005] Among secondary batteries currently commercialized, there are nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries are attracting attention because they have advantages of freedom of charging and discharging due to almost no memory effect, very low self-discharge rate, and high energy density compared to nickel-based secondary batteries.

[0006] On the other hand, although these secondary batteries are sometimes used as a single secondary battery, they are usually used as a plurality of secondary batteries connected in series and / or in parallel to provide a high-voltage and / or large-capacity power storage device. In addition, a plurality of secondary batteries are used in the form of a battery pack having a battery management system (BMS) for controlling overall charging and discharging operations of the secondary batteries inside.

[0007] In such a high-voltage and large-capacity power storage device using secondary batteries, it is very important to maintain insulation. When insulation is not maintained, leakage current can occur, thereby shortening the life of the battery, causing malfunction of electrical devices connected to the battery, and causing carelessness accidents such as electric shock. SUMMARY

[0008] [TECHNICAL PROBLEM]

[0009] One aspect of embodiments disclosed herein is to provide a battery pack and a diagnosis method thereof in which insulation breakdown of a battery cell is detectable.

[0010] Technical problems of embodiments disclosed herein are not limited to the foregoing problems and other problems not mentioned will be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

[0011] [TECHNICAL SOLUTION]

[0012] According to embodiments disclosed herein, a battery pack includes: a battery cell including a pouch configured to cover a positive material and a negative material, a first terminal, and a second terminal; a connector including a transistor configured to connect the pouch and the first terminal; and a controller configured to measure an inrush current flowing into the connector and diagnose a state of the battery cell based on the inrush current.

[0013] According to embodiments, the transistor can be configured to be turned on when a voltage between both ends of the connector exceeds a preset range.

[0014] According to embodiments, during charging of the battery cell, a current can flow from the connector into the first terminal when the transistor is turned on.

[0015] According to embodiments, when the battery cell is charged, a voltage at a node where the connector contacts the pouch can be higher than a voltage at a node where the connector contacts the first terminal.

[0016] According to embodiments, during discharging of the battery cell, a current can flow from the connector into the pouch when the transistor is turned on.

[0017] According to embodiments, when the battery cell is discharged, a voltage at a node where the connector contacts the pouch can be lower than a voltage at a node where the connector contacts the first terminal.

[0018] According to embodiments, the preset range can be set based on a voltage difference between the first terminal and the second terminal.

[0019] According to embodiments, the battery pack can further include a conductive portion placed on one side of the pouch, wherein the connector can be configured to connect the first terminal and the pouch.

[0020] According to embodiments, the controller can be configured to identify that the battery cell is in an insulation breakdown state when the inrush current has a magnitude higher than or equal to a preset value.

[0021] According to embodiments, the battery pack can further include an additional battery cell electrically connected to the battery cell, wherein the controller can be configured to cut off the battery cell by electrically separating the battery cell from the additional battery cell.

[0022] According to embodiments, the controller can be configured to notify a user of the insulation breakdown of the battery cell.

[0023] According to embodiments disclosed herein, a battery diagnosis method includes an operation of connecting a first terminal of a battery cell and a pouch of the battery cell by a transistor, the battery cell including the pouch configured to cover a positive electrode material and a negative electrode material, the first terminal, and a second terminal; an operation of measuring an inrush current flowing into the transistor; and an operation of diagnosing a state of the battery cell based on the inrush current flowing into the transistor.

[0024] According to embodiments, the operation of diagnosing can include an operation of identifying that the battery cell is in an insulation breakdown state when the inrush current flowing into the transistor has a magnitude higher than or equal to a preset value.

[0025] According to embodiments, the battery diagnosis method can further include, after the operation of diagnosing, an operation of cutting off the battery cell by electrically separating the battery cell from an additional battery cell electrically connected to the battery cell.

[0026] According to embodiments, the battery diagnosis method can further include, after the operation of cutting off, an operation of notifying a user of an insulation breakdown of the battery cell.

[0027] According to embodiments, the transistor can be turned on when a voltage between both ends of the transistor exceeds a preset range.

[0028] According to embodiments, when the battery cell is charged, a voltage at a node where the transistor contacts the pouch can be higher than a voltage at a node where the transistor contacts the first terminal, and when the transistor is turned on, a current can flow from the transistor into the first terminal.

[0029] According to embodiments, when the battery cell is discharged, a voltage at a node where the transistor contacts the pouch can be lower than a voltage at a node where the transistor contacts the first terminal, and when the transistor is turned on, a current can flow from the transistor into the pouch.

[0030] According to embodiments, the preset range can be set based on a voltage difference between the first terminal and the second terminal.

[0031] Details of other embodiments are included in the detailed description and the accompanying drawings.

[0032] [Advantageous Effects]

[0033] In a battery pack and a diagnosis method thereof according to embodiments disclosed herein, an insulation breakdown of a battery cell is diagnosed.

[0034] In a battery pack and a diagnosis method thereof according to embodiments disclosed herein, an insulation breakdown of a battery cell is diagnosed during charging and discharging of the battery pack without damaging the battery pack.

[0035] Effects of the battery pack and the diagnosis method thereof according to the embodiments disclosed herein are not limited to the foregoing effects, and those skilled in the art will clearly understand other unmentioned effects from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a block diagram illustrating a battery control system according to the embodiments disclosed herein.

[0037] Figure 2 is a schematic diagram illustrating a battery cell and a connector according to the embodiments disclosed herein.

[0038] Figure 3 is a graph illustrating a soft-pack voltage of a battery cell when the battery cell according to the embodiments disclosed herein is in a normal state.

[0039] Figure 4 is a graph illustrating a soft-pack voltage of a battery cell when the battery cell according to the embodiments disclosed herein is in an abnormal state.

[0040] Figure 5 is a graph illustrating an inrush current based on a soft-pack voltage in a state of charge of a battery cell according to the embodiments disclosed herein.

[0041] Figure 6 is a graph illustrating an inrush current based on a soft-pack voltage in a state of discharge of a battery cell according to the embodiments disclosed herein.

[0042] Figure 7 is a flowchart illustrating a battery diagnosis method according to the embodiments disclosed herein.

[0043] Figure 8 is a block diagram illustrating a computing system for implementing a battery diagnosis method according to the embodiments disclosed herein.

[0044] With regard to the description of the drawings, the same or similar reference numerals can refer to the same or similar elements. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the disclosure will be described with reference to the accompanying drawings. However, the description is not intended to limit the disclosure to specific embodiments, and the embodiments of the disclosure should be interpreted to include all modifications, equivalents, and / or alternatives.

[0046] Embodiments of the present disclosure and the terms used herein do not limit the technical features described in the present disclosure to particular embodiments and should be construed as including various modifications, equivalents or alternatives of the technical features. With regard to the description of the drawings, like reference numerals can be used to refer to like or similar elements. It is to be understood that the singular forms "a," "an," and "the" include one or more of the things referred to unless the relevant context clearly dictates otherwise.

[0047] In the present disclosure, each of such phrases as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C" can include all possible combinations of the items in the phrases. As used herein, such terms as "first," "second," "1st," "2nd," "A," "B," "(a)," or "(b)" can be used to distinguish a corresponding element from another element with the same or similar names or numbers, and do not limit the elements in other aspects (e.g., importance or order) unless specifically specified otherwise.

[0048] It should be understood that if an element (e.g., a first element) is referred to as being "connected to," "coupled to," or "joined to" another element (e.g., a second element) with or without the term "operatively" or "communicatively," it can be directly connected to the other element or connected to the other element via a third element.

[0049] The method according to various embodiments of the present disclosure can be included and provided in a computer program product. The computer program product can be traded as a product between a seller and a buyer. The computer program product can be distributed in the form of a machine-readable storage medium (e.g., CD-ROMs, RAMs, floppy disks, hard disks, optical disks, or magneto-optical disks) or be distributed online through an application store (e.g., Google Play StoreTM, App Store®, or RAM). If distributed online, at least a portion of the computer program product can be temporarily generated or at least temporarily stored in the memory of the manufacturer's server, an application store's server, or a relay server.

[0050] According to various embodiments, each of the above-described elements (e.g., a module or a program) can include a single entity or multiple entities. Some of the multiple entities can be placed in another element. According to various embodiments of the present disclosure, one or more of the above-described elements or operations can be omitted, or one or more other elements or operations can be added. Alternatively or additionally, a plurality of elements (e.g., modules or programs) can be integrated into a single element. In such a case, the integrated element can still perform one or more functions of each of the plurality of elements in the same or similar manner as they are performed by a corresponding one of the plurality of elements before the integration. According to various embodiments of the present disclosure, operations performed by the module, the program, or another element can be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations can be executed in a different order or omitted, or one or more other operations can be added.

[0051] Figure 1 is a block diagram illustrating a battery control system according to an embodiment of the disclosure. Figure 2 is a schematic view illustrating a battery cell and a connector according to an embodiment of the disclosure.

[0052] Referring to Figure 1 , the battery control system can include a battery pack and a higher-level controller.

[0053] The battery pack 10 can include a plurality of battery cells 100, a switching unit 400 connected in series to first and / or second terminals 112 and 113 of the battery cells 110 and configured to control charging and discharging currents of the battery cells 110, and a battery management system 200 configured to monitor voltages, currents, temperatures, etc. of the battery pack 10 and prevent overcharging and overdischarging, etc.

[0054] The battery pack 10 can include the battery cells 110, a sensor 300, the switching unit 400, and the battery management system 200. Here, the switching unit 400 refers to a device for controlling charging or discharging currents of the plurality of battery cells 110, which can employ at least one relay, a magnetic contactor, etc., for example, according to a specification of the battery pack 10. The sensor 300 can be connected to the plurality of battery cells 100 and configured to obtain information about the plurality of battery cells 100. In addition, the sensor 300 can transmit information obtained from the plurality of battery cells 100 to the battery management system 200.

[0055] The battery management system 200 refers to an interface for receiving measurement values of the above-described various parameters, which can include a plurality of terminals, a controller 210 connected to the terminals and configured to process input values, a circuit, etc. Further, the battery management system 200 can be configured to control the on / off of the switching unit 400, and can be connected to each battery cell 110 and configured to monitor the state of each battery cell 110.

[0056] The controller 210 can be configured to diagnose the state of the plurality of battery cells 100. The controller 210 can be configured to measure the current of each connector 120 included in each of the plurality of battery cells 100, and based thereon can diagnose the state of each battery cell 110. Here, the current of the connector 120 can be defined as an inrush current. In this regard, details will be described with reference to Figures 3 to 6

[0057] When the battery cell 110 is diagnosed as abnormal, the controller 210 can be configured to provide information about the battery cell 110 to the user. For example, the controller 210 can be configured to provide information about the abnormal battery cell 110 not only to the user terminal through a communication unit (not shown) but also to the display provided in the vehicle, the charger, etc.

[0058] The upper controller 20 can be configured to transmit a control signal for the battery cell 110 to the battery management system 200. Accordingly, the operation of the battery management system 200 can be controlled based on the signal transmitted from the upper controller 20.

[0059] According to an embodiment, the battery management system 200 can include a controller 210 of Figure 1 According to an alternative embodiment, the battery management system 200 can be a system different from the controller 210 of Figure 1 The following operations of the controller 210 can be performed by various devices, such as a server, a cloud, and a built-in battery management system (BMS) of the charger or the charger / discharger, and the vehicle.

[0060] Referring to Figure 2 , the plurality of battery cells 100 can include the battery cell 110 and the connector 120. Further, each battery cell 110 can include a pouch 111, a first terminal 112, and a second terminal 113. Here, the pouch 111 can refer to a housing of the battery cell 110 configured to cover the positive material, the negative material, the separator, and the electrolyte of the battery. Accordingly, the pouch 111 can form the appearance of the battery cell 110.

[0061] ​The first terminal 112 can be a (+) terminal of the battery cell 110, and the second terminal 113 can be a (-) terminal. According to an embodiment, the first terminal 112 and the second terminal 113 can protrude from the outside of the pouch 111. In other words, the first terminal 112 and the second terminal 113 can not be covered by the pouch 111.

[0062] The connector 120 can be configured to connect the first terminal 112 and the pouch 111 or the second terminal 113 and the pouch 111. In other words, the connector 120 can connect the first terminal 112 and the pouch 111, or can connect the second terminal 113 and the pouch 111. For ease of description, a description will be made based on an assumption that the connector 120 connects the first terminal 112 and the pouch 111.

[0063] The connector 120 can include a transistor 121 and a wire 122. According to an embodiment, the transistor 121 can be a bipolar junction transistor (BJT), but is not limited to the bipolar junction transistor (BJT). The transistor 121 can be configured to perform a current amplification or a switching function based on a voltage applied to two terminals of the transistor 121.

[0064] The transistor 121 can connect the first terminal 112 and one side of the pouch 111. Specifically, the wire 122 can be configured to connect the first terminal 112 and the transistor 121, and to connect the transistor 121 and one side of the pouch 111. In other words, the transistor 121 can connect the first terminal 112 and one side of the pouch 111 using the wire 122.

[0065] According to an embodiment, the conductive portion 114 can be placed on one side of the pouch 111. Here, the conductive portion 114 can contain a material such as a metal having electrical conductivity. In this case, the transistor 121 can connect the first terminal 112 of the battery cell 110 and the conductive portion 114.

[0066] A point at which the connector 120 contacts the first terminal 112 can be defined as a first node s1. In addition, a point at which the connector 120 contacts one side of the pouch 111 or the conductive portion 114 can be defined as a second node s2.

[0067] The connector 120 is configured to operate based on a voltage between the first node s1 and the second node s2. For example, the transistor 121 included in the connector 120 can be configured to be turned on when the voltage between the first node s1 and the second node s2 exceeds a preset range. In other words, the transistor 121 can be configured not to operate when the voltage between the first node s1 and the second node s2 is within the preset range, but to be turned on when the voltage between the first node s1 and the second node s2 exceeds the preset range. Here, the voltage between the first node s1 and the second node s2 can be defined as a soft pack 111 voltage. In other words, the soft pack 111 voltage can refer to a value obtained by subtracting the voltage of the first node s1 from the voltage of the second node s2.

[0068] The preset range can be set in consideration of a voltage difference between the first terminal 112 and the second terminal 113 and a driving voltage of the transistor 121. For example, when the voltage difference between the first terminal 112 and the second terminal 113 is large, the preset range can be set to be wide. When the voltage difference between the first terminal 112 and the second terminal 113 is small, the preset range can be set to be narrow. In addition, the upper and lower limits of the preset range can be set based on the driving voltage of the transistor 121. In other words, the preset range a can be set to operate the transistor 121 when the soft pack 111 voltage exceeds the preset range.

[0069] Figure 3 FIG. 1 is a graph illustrating a soft pack voltage of a battery cell when the battery cell according to an embodiment disclosed herein is in a normal state.

[0070] Referring to FIG. 1, Figure 3 The controller 210 can be configured to obtain voltage information about the battery cell 110. Here, the voltage information about the battery cell 110 can include a charging voltage, a discharging voltage, and a soft pack 111 voltage. The charging voltage can refer to a voltage between the first terminal 112 and the second terminal 113 of the battery cell 110 based on charging of the battery cell 110. The charging voltage can increase as the charging proceeds. The discharging voltage can refer to a voltage between the first terminal 112 and the second terminal 113 of the battery cell 110 based on discharging of the battery cell 110. The discharging voltage can decrease as the discharging proceeds.

[0071] The soft-pack 111 voltage can refer to a voltage between the first terminal 112 of the battery cell 110 and the soft-pack 111. In other words, the soft-pack 111 voltage can refer to a voltage between a first node s1 connecting the connector 120 and the first terminal 112 and a second node s2 connecting the connector 120 and one side of the soft-pack 111. When the battery cell 110 is in a normal state, an insulating state of the soft-pack 111 is maintained. Accordingly, the second node s2 can serve as a resistance on an equivalent circuit. Accordingly, the soft-pack 111 voltage is maintained within a certain range regardless of charging or discharging of the battery cell 110. Here, the certain range can correspond to the aforementioned preset range a. In other words, the soft-pack 111 voltage can vary within the preset range a when the battery is charged or discharged. According to an embodiment, the preset range a can be within a range from 0 [V] to 0.5 [V].

[0072] Figure 4 is a graph illustrating a soft-pack voltage of a battery cell when the battery cell according to an embodiment disclosed herein is in an abnormal state.

[0073] Referring to Figure 4 , the soft-pack voltage can exceed the preset range a according to a state of the battery cell 110. When the insulation of the soft-pack 111 of the battery cell 110 is broken, the soft-pack 111 can come into contact with an electrolyte inside the soft-pack 111. According to an embodiment, the soft-pack 111 can include an aluminum layer, and thus when the aluminum layer comes into contact with the electrolyte, a voltage of the second node s2 can be affected by the electrolyte. Accordingly, the second node s2 can serve as a voltage source on an equivalent circuit. In other words, the voltage at the second node s2 can vary, and the voltage between the first node s1 and the second node s2, i.e., the soft-pack voltage, can also vary.

[0074] Specifically, when the soft-pack 111 voltage is measured while the battery cell 110 in which the insulation has been broken is charged, the soft-pack 111 voltage can exceed the preset range a. In this case, the soft-pack 111 voltage can be defined as a first voltage V12. The insulation breakage of the battery cell 110 can cause a short circuit between the soft-pack 111 and the electrolyte inside the soft-pack 111, and thus the electrolyte can cause the voltage of the second node s2 to increase compared to the voltage of the first node s1. Accordingly, the voltage difference between the second node s2 and the first node s1, i.e., the soft-pack 111 voltage, can increase beyond the preset range a. In other words, the first voltage V12 can exceed the preset range a. According to an embodiment, the first voltage V12 can be higher than or equal to 0.5 [V].

[0075] When the soft-pack 111 voltage is measured while the battery cell 110 whose insulation has been broken is discharged, the soft-pack 111 voltage can exceed the preset range a. In this case, the soft-pack 111 voltage can be defined as a second voltage V12. The insulation breakage of the battery cell 110 can cause a short circuit between the soft-pack 111 and the electrolyte inside the soft-pack 111, and thus the electrolyte causes the voltage of the second node s2 to decrease compared to the voltage of the first node s1. Accordingly, the voltage difference between the second node s2 and the first node s1, that is, the soft-pack 111 voltage can decrease beyond the preset range a. In other words, the second voltage V12 can exceed the preset range a. According to an embodiment, the second voltage V12 can be lower than 0 [V].

[0076] Figure 5 is a graph showing a soft-pack voltage-based inrush current in a charged state of a battery cell according to an embodiment disclosed herein.

[0077] Referring to Figure 5 , when the battery cell 110 is charged, an inrush current can be generated based on the soft-pack 111 voltage. In Figure 5 , the graph shows a soft-pack voltage-based inrush current in a charged state of a battery cell according to an embodiment disclosed herein.

[0078] When the soft-pack 111 voltage is within the preset range a, the transistor 121 can be in an OFF state. Accordingly, the magnitude of the inrush current can be constant. According to an embodiment, when the transistor 121 is in the OFF state, the magnitude of the inrush current can be lower than or equal to a preset value.

[0079] When the magnitude of the inrush current is lower than or equal to the preset value, the controller 210 can identify that the battery cell 110 is in a normal state. According to an embodiment, when the magnitude of the inrush current is lower than or equal to the preset value, the controller 210 can identify that the insulation of the battery cell 110 is in a normal state.

[0080] When the soft-pack 111 voltage exceeds the preset range a, the transistor 121 can be turned on. Accordingly, the voltage at the second node s2 increases due to the electrolyte, and the voltage difference between the second node s2 and the first node s1 increases, thereby increasing the soft-pack 111 voltage. Accordingly, the soft-pack 111 voltage becomes to exceed the preset range a and the transistor 121 is turned on, thereby generating a forward inrush current. Here, the forward inrush current can refer to a current flowing from the soft-pack 111 to the first terminal 112 via the connector 120.

[0081] When the forward rush current is higher than a preset value, the controller 210 can identify that the battery cell 110 is in an abnormal state. In other words, the controller 210 can identify the state of the battery cell 110 based on the magnitude of the rush current. According to an embodiment, when the magnitude of the rush current is equal to or higher than the preset value, the controller 210 can identify that the insulation of the battery cell 110 is in a breakdown state.

[0082] According to an alternative embodiment, the controller 210 can identify the state of the battery cell 110 based on the rate of change of the rush current. In this case, when the differential value of the rush current is higher than or equal to a preset value, the controller 210 can identify that the battery cell 110 is in an abnormal state.

[0083] When the breakdown state of the insulation of the battery cell 110 is identified, the controller 210 can transmit information about the battery cell 110 to a user. Here, the information about the battery cell 110 can include an identification number of the battery cell 110, an insulation state, a magnitude of the rush current, etc.

[0084] The controller 210 can cut off the battery cell 110 identified as being in the breakdown state of the insulation. According to an embodiment, the controller 210 can cause a switch (not shown) connecting the battery cell 110 identified as being in the breakdown state of the insulation and an additional battery cell to be turned off, thereby electrically separating the battery cell 110 identified as being in the breakdown state of the insulation from the additional battery cell. Here, the additional battery cell can refer to other battery cells 110 among the plurality of battery cells 100 except for the battery cell 110 identified as being in the breakdown state of the insulation.

[0085] Figure 6 FIG. 4 is a graph illustrating a soft-pack voltage-based rush current in a discharge state of a battery cell according to an embodiment disclosed herein.

[0086] Referring to FIG. 4, Figure 6 When the battery cell 110 is discharged, a rush current can be generated based on a soft-pack 111 voltage. In Figure 6 In the graph shown in FIG. 4, the abscissa corresponds to the soft-pack 111 voltage, and the ordinate corresponds to the rush current.

[0087] When the soft-pack 111 voltage is within a preset range a, the transistor 121 can be in an OFF state. Accordingly, the magnitude of the rush current can be constant. According to an embodiment, when the transistor 121 is in the OFF state, the magnitude of the rush current can be lower than or equal to a preset value.

[0088] When the size of the inrush current is lower than or equal to the preset value, the controller 210 can identify that the battery cell 110 is in a normal state. According to an embodiment, when the size of the inrush current is lower than or equal to the preset value, the controller 210 can identify that the insulation of the battery cell 110 is in a normal state.

[0089] When the soft-pack 111 voltage exceeds the preset range a, the transistor 121 can be turned on. Accordingly, the voltage at the second node s2 is lowered due to the electrolyte, and the voltage at the second node s2 becomes lower than the voltage at the first node s1, thereby causing the soft-pack 111 voltage to become excessive from the preset range. Accordingly, the transistor 121 is turned on, thereby generating a reverse inrush current. Here, the reverse inrush current can refer to a current flowing from the first terminal 112 to the soft-pack 111 via the connector 120.

[0090] When the reverse inrush current is higher than the preset value, the controller 210 can identify that the battery cell 110 is in an abnormal state. In other words, the controller 210 can identify the state of the battery cell 110 based on the size of the inrush current. According to an embodiment, when the size of the inrush current is equal to or higher than the preset value, the controller 210 can identify that the insulation of the battery cell 110 is in a breakdown state.

[0091] According to an alternative embodiment, the controller 210 can identify the state of the battery cell 110 based on the size of the rate of change of the inrush current. In this case, when the size of the differential value of the inrush current is higher than or equal to the preset value, the controller 210 can identify that the battery cell 110 is in an abnormal state.

[0092] As the battery cell 110 is charged, even when it is discharged, the controller 210 can inform a user of the state of the battery cell 110 or cut off the battery cell 110.

[0093] According to an embodiment, the battery pack 10 can connect the first terminal 112 and the soft-pack 111 in each of the plurality of battery cells 100 through the connector 120 and measure the current of the connector 120, thereby diagnosing each individual insulation breakdown of the battery cell 110 included in the battery pack 10. In other words, each individual state of the plurality of battery cells 100 included in the battery pack 10 can be diagnosed based on the current of the connector 120 during charging or discharging of the battery pack 10 without individually damaging or disassembling the battery pack 10. Furthermore, the state of the battery cell 110 can be diagnosed simultaneously with the charging or discharging of the battery pack 10, thereby cutting off the battery cell 110 in which the insulation has been broken down immediately when the battery pack 10 is charged or discharged, or informing a user of the insulation breakdown so that she / he can take measures immediately. Accordingly, the battery cell 110 in the insulation breakdown state is prevented from generating heat, explosion, etc. due to continuous charging or discharging.

[0094] Figure 7 is a flowchart illustrating a battery diagnosis method according to an embodiment disclosed herein.

[0095] Figure 7 The embodiments illustrated in the drawings are merely examples and the order of operations according to various embodiments of the disclosure can be different from Figure 7 those illustrated in the drawings. For example, Figure 7 Some operations illustrated in the drawings can be omitted, changed in order, or merged.

[0096] Referring to Figure 7 , the battery diagnosis method can include the following operations: connecting a first terminal 112 and a pouch 111 of a battery cell 110 through a transistor 121 (S100), wherein the battery cell 110 includes the pouch 111 configured to cover a positive electrode material and a negative electrode material, the first terminal 112, and a second terminal 113; measuring a size of an inrush current flowing into the transistor 121 from the first terminal 112 or the pouch 111 when the battery cell 110 is charged or discharged (S200); identifying whether the size of the current flowing into the transistor 121 is higher than or equal to a preset current value (S300); identifying that the battery cell 110 is normal (S400); cutting off the battery cell 110 (S500); and notifying a user of insulation breakdown of the battery cell 110 (S600).

[0097] Hereinafter, operations S100 to S600 will be described in detail with reference to Figures 1 to 6 .

[0098] At operation S100, the battery pack 10 can be configured to connect the first terminal 112 and the pouch 111 of the battery cell 110 through the transistor 121, wherein the battery cell 110 includes the pouch 111 configured to cover a positive electrode material and a negative electrode material, the first terminal 112, and a second terminal 113. According to an embodiment, the battery pack 10 can include the transistor 121, and the transistor 121 can be configured to connect each of the first terminal 112 and the pouch 111 of the battery cell 110, or to connect the first terminal 112 and the conductive portion 114 placed on the pouch 111. According to an embodiment, the first terminal 112 of each of the battery cells 110, the transistor 121, and the pouch 111 can be connected in a process of manufacturing the battery pack 10.

[0099] At operation S200, the battery pack 10 can measure the size of the inrush current flowing into the transistor 121 from the first terminal 112 or the pouch 111 when the battery cell 110 is charged or discharged. The battery pack 10 can measure the size of the inrush current flowing from the pouch 111 to the connector 120 or from the first terminal 112 to the connector 120 based on the voltage of the pouch 111 during charging or discharging of the battery pack 10.

[0100] In operation S300, the battery pack 10 can identify whether the size of the current flowing into the transistor 121 is higher than or equal to a preset current value. When the size of the inrush current is higher than or equal to the preset current value, the battery pack 10 can perform operation S500. When the size of the inrush current is lower than the preset current value, the battery pack 10 can perform operation S400. According to an alternative embodiment, the battery pack 10 can also identify the state of the battery cell 110 based on the size of the rate of change of the inrush current. In other words, in this case, the battery pack 10 can perform operation S500 when the size of the rate of change of the inrush current is higher than or equal to a preset value, and perform operation S400 when the size of the rate of change of the inrush current is lower than the preset value.

[0101] In operation S400, the battery pack 10 can identify that the battery cell 110 is normal. In other words, the battery pack 10 can identify that the insulation of the battery cell 110 is in a normal state.

[0102] In operation S500, the battery pack 10 can cut off the battery cell 110. The battery pack 10 can identify that the battery cell 110 is in an insulation breakdown state. According to an embodiment, the battery pack 10 can turn off a switch (not shown) connecting the battery cell 110 identified as being in the insulation breakdown state and an additional battery cell, thereby electrically separating the battery cell 110 identified as being in the insulation breakdown state from the additional battery cell. Here, the additional battery cell can refer to other battery cells 110 among the plurality of battery cells 100 except for the battery cell 110 identified as being in the insulation breakdown state.

[0103] In operation S600, the battery pack 10 can notify a user of the insulation breakdown of the battery cell 110. When the state of the battery cell 110 is identified as being in the insulation breakdown state, the battery pack 10 can be configured to transmit information about the battery cell 110 to the user. For example, the battery pack 10 can be configured to not only provide information about the abnormal battery cell 110 to a user terminal through a communication unit (not shown), but also provide information about the abnormal battery cell 110 through a display provided in a vehicle, a charger, etc. Here, the information about the battery cell 110 can include an identification number of the battery cell 110, an insulation state, a size of the inrush current, etc.

[0104] Figure 8 is a block diagram illustrating a computing system for implementing a battery diagnosis method according to an embodiment disclosed herein.

[0105] Referring to Figure 8 , the computing system 500 according to an embodiment disclosed herein can include a microcontroller unit (MCU) 510, a memory 520, an input / output interface (I / F) 530, and a communication I / F 540.

[0106] The MCU 510 can refer to a processor that executes various programs (e.g., a state of health (SOH) calculation program, a cell balancing target identification program, etc.) stored in the memory 520, processes various data including a state of charge (SOC), an SOH, etc. of a plurality of battery cells through such programs, and implements the functions of the battery pack 10 described above with reference to FIGS. 1 to 4. Figures 1 to 6 The functions of the battery pack 10 described above are implemented.

[0107] The memory 520 can be configured to store various programs related to SOH calculation and cell balancing target identification of battery cells. In addition, the memory 520 can be configured to store various data such as SOC and SOH data of each battery cell.

[0108] Such a memory 520 can include a plurality of memories 520 as necessary. The memory 520 can include a volatile memory or a non-volatile memory. As a volatile memory, the memory 520 can employ a random access memory (RAM), a dynamic RAM (DRAM), a static RAM (SRAM), etc. As a non-volatile memory, the memory 520 can employ a read only memory (ROM), a programmable ROM (PROM), an electrically alterable ROM (EAROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, etc. The memory 520 listed above is merely an example, and is not limited to these examples.

[0109] The input / output I / F 530 can provide an interface that connects an input unit (not shown) such as a keyboard, a mouse, a touch panel, etc., an output unit such as a display (not shown), etc., and the MCU 510 to transmit and receive data.

[0110] The communication I / F 540 can refer to various devices that support wired or wireless communication as an element for transmitting various data to a server and receiving various data from the server. For example, a program for calculating an SOH of a battery cell or identifying a balancing target, various data, etc. can be transmitted to or received from a separately provided external server through the communication I / F 540.

[0111] In this way, the battery diagnosis method according to the embodiments disclosed herein can be recorded in the memory 520 and executed by the MCU 510.

[0112] The foregoing description is merely illustrative of the technical spirit of the embodiments disclosed herein, and those of ordinary skill in the art to which the embodiments disclosed herein belong can make various modifications and changes without departing from the scope of the essential characteristics of the embodiments disclosed herein.

[0113] Accordingly, the embodiments disclosed herein are not intended to be limiting, but to illustrate a technique spirit of the present disclosure. The scope of the technique spirit disclosed herein is not limited by these embodiments. The scope of the technique spirit disclosed herein should be interpreted based on the appended claims, and all technique spirits within an equivalent scope should be interpreted as falling within the scope of the present disclosure.

[0114] [Description of Reference Numerals]10: battery pack

[0115] 100: plurality of battery cells110: battery cell

[0116] 120: connector

[0117] 121: transistor

[0118] 210: controller

Claims

1. A battery pack comprising: a battery cell including a pouch configured to cover a positive material and a negative material, a first terminal, and a second terminal; a connector including a transistor configured to connect the pouch and the first terminal; and a controller configured to measure an inrush current flowing into the connector and diagnose a state of the battery cell based on the inrush current. The transistor is configured to be turned on when a voltage between both ends of the transistor exceeds a preset range.

2. The battery pack of claim 1, wherein, During charging of the battery cell, a current flows from the connector into the first terminal when the transistor is turned on.

3. The battery pack of claim 2, wherein, When the battery cell is charged, a voltage at a node where the connector contacts the pouch is higher than a voltage at a node where the connector contacts the first terminal.

4. The battery pack of claim 2, wherein, During discharging of the battery cell, a current flows from the connector into the pouch when the transistor is turned on.

5. The battery pack of claim 2, wherein, When the battery cell is discharged, a voltage at the node where the connector contacts the pouch is lower than a voltage at the node where the connector contacts the first terminal.

6. The battery pack of claim 2, wherein, The preset range is set based on a voltage difference between the first terminal and the second terminal.

7. The battery pack of claim 2, wherein, 8.The battery pack of claim 1, further comprising a conductive portion placed on one side of the pouch, The connector is configured to connect the first terminal and the pouch. wherein The controller is configured to identify that the battery cell is in an insulation breakdown state when the inrush current has a magnitude higher than or equal to a preset value.

9. The battery pack of claim 1, wherein, 10.The battery pack of claim 9, further comprising an additional battery cell electrically connected to the battery cell, The controller is configured to cut off the battery cell by electrically separating the battery cell from the additional battery cell. wherein The controller is configured to notify a user of insulation breakdown of the battery cell.

11. The battery pack of claim 10, wherein, 12.A battery diagnosis method comprising: an operation of connecting a first terminal of a battery cell and a pouch of the battery cell through a transistor, the battery cell including the pouch configured to cover a positive material and a negative material, the first terminal, and a second terminal; an operation of measuring an inrush current flowing into the transistor; and an operation of diagnosing a state of the battery cell based on the inrush current flowing into the transistor. The operation of diagnosing includes an operation of identifying that the battery cell is in an insulation breakdown state when the inrush current flowing into the transistor has a magnitude higher than or equal to a preset value. After the operation of diagnosing, an operation of cutting off the battery cell by electrically separating the battery cell from an additional battery cell electrically connected to the battery cell.

13. The battery diagnostic method of claim 12, wherein, After the operation of cutting off, an operation of notifying a user of insulation breakdown of the battery cell.

14. The battery diagnostic method of claim 13, further comprising: The transistor is turned on when a voltage between both ends of the transistor exceeds a preset range.

15. The battery diagnostic method of claim 14, further comprising: 17.The battery diagnosis method of claim 16, wherein, 16. The battery diagnostic method of claim 12, wherein, When the battery cell is charged, a voltage at a node where the transistor contacts the pouch is higher than a voltage at a node where the transistor contacts the first terminal, and ​ ​ When the transistor is turned on, current flows from the transistor into the first terminal.

18. The battery diagnostic method of claim 16, wherein, When the battery cell is discharging, the voltage at the node where the transistor is in contact with the soft pack is lower than the voltage at the node where the transistor is in contact with the first terminal, and When the transistor is turned on, current flows from the transistor into the soft pack.

19. The battery diagnostic method of claim 16, wherein, The preset range is set based on a voltage difference between the first terminal and the second terminal.

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