Battery pack and this diagnostic method

Abstract

A battery pack according to one embodiment disclosed herein includes a pouch covering a positive electrode material and a negative electrode material, a battery cell including a first terminal and a second terminal, a connection part including a transistor connecting the pouch and the first terminal, and a controller that measures the inflow current flowing into the connection part and diagnoses the state of the battery cell based on the inflow current.

Description

Technical Field

[0001] [Cross - reference to Related Applications] The present invention claims the benefit of priority based on Korean Patent Application No. 10 - 2023 - 0087011, filed on July 5, 2023, and includes all the contents disclosed in the documents of the Korean patent application as part of this specification.

[0002] Embodiments disclosed in this document relate to a battery pack and a diagnostic method thereof.

Background Art

[0003] Currently commercialized secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, lithium secondary batteries, etc. Among these, lithium secondary batteries have attracted attention due to advantages such as almost no memory effect, free charging, very low self - discharge rate, and high energy density compared to nickel - based secondary batteries.

[0004] On the other hand, such secondary batteries may be used as a single secondary battery, but are often used as a plurality of secondary batteries connected in series and / or parallel to provide a high - voltage and / or high - capacity power storage device. Furthermore, a plurality of secondary batteries are used in the form of a battery pack including a battery management device that generally controls charge and discharge operations.

[0005] For such high - voltage, high - capacity power storage devices using secondary batteries, it is very important to maintain insulation. If the insulation state cannot be maintained, not only will leakage current occur and the battery life be shortened, but it may also cause malfunctions of electrical equipment connected to the battery and lead to serious accidents such as electric shock.

Summary of the Invention

Problems to be Solved by the Invention

[0006] One objective of the embodiments disclosed in this document is to provide a battery pack and a diagnostic method capable of detecting dielectric breakdown of battery cells.

[0007] The technical problems of the embodiments described herein are not limited to those mentioned above, and any other technical problems not mentioned should be clearly understood by a person ordinary in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0008] A battery pack according to one embodiment disclosed herein includes a pouch configured to cover a positive electrode material and a negative electrode material; a battery cell including a first terminal and a second terminal; a connection portion including a transistor configured to connect the pouch and the first terminal; and a controller configured to measure the inflow current flowing into the connection portion and to diagnose the state of the battery cell based on the inflow current.

[0009] According to one embodiment, the transistor may be configured to turn on when the voltage across the connection falls outside a predetermined range.

[0010] According to one embodiment, when the transistor is turned on while the battery cell is being charged, current can flow from the connection to the first terminal.

[0011] According to one embodiment, when the battery cell is being charged, the voltage at the point where the connection part contacts the pouch may be greater than the voltage at the point where the connection part contacts the first terminal.

[0012] According to one embodiment, when the transistor is turned on while the battery cell is discharging, current can flow from the connection to the pouch.

[0013] According to one embodiment, when the battery cell is discharging, the voltage at the point where the connection part contacts the pouch may be lower than the voltage at the point where the connection part contacts the first terminal.

[0014] According to one embodiment, the previously set range may be set based on the voltage difference between the first terminal and the second terminal.

[0015] According to one embodiment, the pouch may further include a conductive portion disposed on one surface of the pouch, and the connecting portion may be configured to connect the first terminal and the pouch.

[0016] According to one embodiment, the controller can be configured to determine that the battery cell is in a state of dielectric breakdown if the magnitude of the incoming current is greater than or equal to a previously set value.

[0017] According to one embodiment, the system further includes an additional battery cell electrically connected to the battery cell, and the controller can electrically isolate the battery cell from the additional battery cell to shut off the battery cell.

[0018] According to one embodiment, the controller may be configured to communicate an alarm to the user regarding dielectric breakdown of the battery cell.

[0019] A battery diagnostic method according to one embodiment disclosed herein includes a pouch configured to cover a positive electrode material and a negative electrode material, the steps of connecting the first terminal of a battery cell, which includes a first terminal and a second terminal, to the pouch with a transistor, measuring the inflow current flowing into the transistor, and diagnosing the state of the battery cell based on the inflow current flowing into the transistor.

[0020] According to one embodiment, the diagnosis may include a step of determining that the battery cell has been short-circuited when the magnitude of the inflow current flowing into the transistor is greater than or equal to a preset value.

[0021] According to one embodiment, the battery diagnosis method may further include a step of electrically separating the battery cell from an additional battery cell electrically connected to the battery cell and blocking the battery cell after the diagnosis.

[0022] According to one embodiment, the battery diagnosis method may further include a step of transmitting an alarm regarding the short-circuit of the battery cell to the user after the blocking step.

[0023] According to one embodiment, the transistor may be turned on when the voltage across the transistor deviates from a preset range.

[0024] According to one embodiment, when the battery cell is being charged, the voltage at the point where the transistor contacts the pouch is greater than the voltage at the point where the transistor contacts the first terminal, and when the transistor is turned on, current may flow from the transistor into the first terminal.

[0025] According to one embodiment, when the battery cell is being discharged, the voltage at the point where the transistor contacts the pouch is less than the voltage at the point where the transistor contacts the first terminal, and when the transistor is turned on, current may flow from the transistor into the pouch.

[0026] According to one embodiment, the preset range may be set based on the voltage difference between the first terminal and the second terminal.

[0027] Specific matters of other embodiments are included in the detailed description and the drawings.

Advantages of the Invention

[0028] The battery pack and the diagnosis method according to the embodiments disclosed in this document can diagnose the insulation breakdown of battery cells.

[0029] The battery pack and the diagnosis method according to the embodiments disclosed in this document can diagnose the insulation breakdown of battery cells during charging and discharging of the battery pack without damaging the battery pack.

[0030] The effects of the battery pack and the battery diagnosis method according to the disclosure of this document are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the disclosure of this document.

Brief Description of the Drawings

[0031] [Figure 1] It is a block diagram showing a battery control system according to an embodiment disclosed in this document. [Figure 2] It is a schematic diagram showing a battery cell and a connection part according to an embodiment disclosed in this document. [Figure 3] When the battery cell according to an embodiment disclosed in this document is in a normal state, it is a graph showing the pouch voltage of the battery cell. [Figure 4] When the battery cell according to an embodiment disclosed in this document is in an abnormal state, it is a graph showing the pouch voltage of the battery cell. [Figure 5] In the charging state of the battery cell according to an embodiment disclosed in this document, it is a graph showing the inflow current according to the pouch voltage. [Figure 6] In the discharging state of the battery cell according to an embodiment disclosed in this document, it is a graph showing the inflow current according to the pouch voltage. [Figure 7] It is a flowchart showing a battery diagnosis method according to an embodiment disclosed in this document. [Figure 8]This is a block diagram showing a computer system that performs a battery diagnostic method according to one embodiment disclosed in this document.

[0032] With regard to the description of the drawings, the same or similar reference numerals may be used for the same or similar components. [Modes for carrying out the invention]

[0033] Embodiments of the present invention are described below with reference to the accompanying drawings. However, this should not be understood as limiting the present invention to any particular embodiment, but rather as including various modifications, equivalents, and / or alternatives to embodiments of the present invention.

[0034] The embodiments and terminology used herein are not intended to limit the technical features described herein to any particular embodiment, but should be understood to include a variety of modifications, equivalents, or substitutions of such embodiments. In relation to the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of nouns corresponding to items may include one or more of such items unless the context clearly indicates otherwise.

[0035] In this document, each of the phrases “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” may include any one of the items listed with the applicable phrase, or any possible combination thereof. Terms such as “first,” “second,” “primary,” “second,” “A,” “B,” “(a),” or “(b)” may be used simply to distinguish one component from other components and, unless otherwise stated, do not limit the component in any other way (e.g., importance or order).

[0036] In this document, when a component (e.g., the first) is referred to as being "connected," "coupled," or "connected" to another component (e.g., the second), with or without the terms "functionally" or "communically," it means that the first component may be connected to the other component directly (e.g., by wire or wirelessly) or indirectly (e.g., via the third component).

[0037] The methods according to the various embodiments disclosed herein may be provided in a computer program product. The computer program product may be traded as a commodity between sellers and buyers. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory, CD-ROM), or online (e.g., by download or upload) via an application store or directly between two user devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a device-readable storage medium such as the memory of a manufacturer's server, an application store server, or an intermediary server.

[0038] According to the embodiments disclosed herein, each of the components described above (e.g., a module or a program) may include one or more individuals, some of which may be separated and arranged in other components. According to the embodiments disclosed herein, one or more of the aforementioned components or operations may be omitted, or one or more other components or operations may be added. Alternatively or additionally, multiple components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those performed by the components of the multiple components prior to the integration. According to the embodiments disclosed herein, operations performed by a module, program or other component may be performed sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be performed in a different procedure, omitted, or one or more other operations may be added.

[0039] Figure 1 is a block diagram showing a battery control system according to one embodiment disclosed in this document. Figure 2 is a schematic diagram showing a battery cell and connection part according to one embodiment disclosed in this document.

[0040] Referring to Figure 1, the battery control system may include a battery pack and a higher-level controller.

[0041] The battery pack 10 may include a plurality of battery cells 100, a switching unit 400 connected in series to the first terminal 112 and / or second terminal 113 side of the battery cell 110 and configured to control the current flow for charging and discharging the battery cell 110, and a battery management system 200 configured to monitor the voltage, current, temperature, etc. of the battery pack 10 and prevent overcharging and over-discharging.

[0042] The battery pack 10 may be equipped with multiple battery cells 110, sensors 300, switching units 400, and battery management systems 200. Here, the switching unit 400 is an element for controlling the current flow for charging or discharging multiple battery cells 100, and may be, for example, at least one relay, magnetic contactor, etc., depending on the specifications of the battery pack 10. The sensor 300 can be connected to multiple battery cells 100 and configured to acquire information from multiple battery cells 100. The sensor 300 can also transmit the information acquired from the multiple battery cells 100 to the battery management system 200.

[0043] The battery management system 200 is an interface that receives input values ​​of the various parameters mentioned above, and refers to an interface that includes multiple terminals and a controller 210 and circuitry connected to these terminals and configured to process the input values. The battery management system 200 can also control the ON / OFF state of the switching unit 400 and can be connected to the battery cells 110 to monitor the state of each battery cell 110.

[0044] The controller 210 can diagnose the status of multiple battery cells 100. The controller 210 measures the current at the connection points 120 included in each of the multiple battery cells 100 and can diagnose the status of each battery cell 110 based on this. Here, the current at the connection points 120 may be defined as the inflow current. This will be explained in detail later in Figures 3 to 6.

[0045] The controller 210 can be configured to provide information about the battery cell 110 to the user once the diagnostic results confirm that the battery cell 110 is abnormal. For example, the controller 210 can be configured to provide information about the abnormal battery cell 110 to the user terminal via a communication unit (not shown), or it can be configured to provide information about the abnormal battery cell 110 via a display provided in the vehicle or charger, etc.

[0046] The higher-level controller 20 can be configured to transmit control signals to the battery management system 200 for the battery cells 110. This allows the battery management system 200 to be controlled based on the signals applied from the higher-level controller 20.

[0047] According to one embodiment, the battery management system 200 may include the controller 210 shown in Figure 2. According to another embodiment, the battery management system 200 may be a different system from the controller 210 shown in Figure 2. The operation of the controller 210 described below may be performed by a BMS (Battery management system) in the vehicle, as well as by various devices such as a server, cloud, charger, or charger / discharger.

[0048] Referring to Figure 2, the multiple battery cells 100 can include battery cells 110 and connection parts 120. Each battery cell 110 can include a pouch 111, a first terminal 112, and a second terminal 113. Here, the pouch 111 may mean a case for the battery cell 110 configured to cover the positive electrode material, negative electrode material, separator membrane, and electrolyte of the battery. Thus, the pouch 111 can form the outer shape of the battery cell 110.

[0049] The first terminal 112 may be the (+) terminal of the battery cell 110, and the second terminal 113 may be the (-) terminal. According to the embodiment, the first terminal 112 and the second terminal 113 may protrude outside the pouch 111. That is, the first terminal 112 and the second terminal 113 do not need to be covered by the pouch 111.

[0050] The connector 120 can be configured to connect the first terminal 112 to the pouch 111 or the second terminal 113 to the pouch 111. That is, the connector 120 can connect the first terminal 112 to the pouch 111 or the second terminal 113 to the pouch 111. For the sake of explanation, the description will assume that the connector 120 connects the first terminal 112 to the pouch 111.

[0051] The connection 120 may include a transistor 121 and a conductor 122. According to the embodiment, the transistor 121 may be a BJT (Bipolar Junction Transistor), but is not limited thereto. The transistor 121 may be configured to perform a current amplification or switching function based on the voltage across the transistor 121.

[0052] The transistor 121 can connect the first terminal 112 to one side of the pouch 111. Specifically, the wire 122 can be configured to connect the first terminal 112 to the transistor 121 and the transistor 121 to one side of the pouch 111. In other words, the transistor 121 can connect the first terminal 112 to one side of the pouch 111 using the wire 122.

[0053] According to one embodiment, a conductive portion 114 may be arranged on one surface of the pouch 111. Here, the conductive portion 114 may include a material such as an electrically conductive metal. In this case, the transistor 121 can connect the first terminal 112 of the battery cell 110 to the conductive portion 114.

[0054] The point where the connection portion 120 contacts the first terminal 112 may be defined as the first point s1. The point where the connection portion 120 contacts one surface of the pouch 111 or the conductive portion 114 may be defined as the second point s2.

[0055] The connector 120 can be configured to operate based on the voltage between a first point s1 and a second point s2. For example, the transistor 121 included in the connector 120 may be configured to turn on when the voltage between the first point s1 and the second point s2 falls outside a predetermined range. That is, if the voltage between the first point s1 and the second point s2 is within a predetermined range, the transistor 121 is not driven, and if the voltage between the first point s1 and the second point s2 falls outside a predetermined range, the transistor 121 may be turned on. Here, the voltage between the first point s1 and the second point s2 may be defined as the voltage of the pouch 111. That is, the voltage of the pouch 111 may be the value obtained by subtracting the voltage of the first point s1 from the voltage of the second point s2.

[0056] The pre-set range may be set considering the voltage difference between the first terminal 112 and the second terminal 113 and the drive voltage of the transistor 121. For example, if the voltage difference between the first terminal 112 and the second terminal 113 is large, the pre-set range may be set wider. If the voltage difference between the first terminal 112 and the second terminal 113 is small, the pre-set range may be set narrower. In addition, the upper and lower limits of the pre-set range may be set based on the drive voltage of the transistor 121. That is, if the voltage of the pouch 111 falls outside the pre-set range, the pre-set range a can be set so that the transistor 121 is driven.

[0057] Figure 3 is a graph showing the pouch voltage of a battery cell when the battery cell according to one embodiment disclosed in this document is in a normal state.

[0058] Referring to Figure 3, the controller 210 can be configured to acquire voltage information of the battery cell 110. Here, the voltage information of the battery cell 110 can include the charging voltage, the discharging voltage, and the voltage of the pouch 111. The charging voltage may be the voltage between the first terminal 112 and the second terminal 113 of the battery cell 110 due to charging. As charging progresses, the charging voltage may increase. The discharging voltage may be the voltage between the first terminal 112 and the second terminal 113 of the battery cell 110 due to discharging. As discharging progresses, the discharging voltage may decrease.

[0059] The voltage of pouch 111 may be the voltage between the first terminal 112 of the battery cell 110 and pouch 111. That is, the voltage of pouch 111 may be the voltage between a first point s1 where the connector 120 and the first terminal 112 are connected, and a second point s2 where the connector 120 and one side of pouch 111 are connected. When the battery cell 110 is in a normal state, pouch 111 can maintain insulation. As a result, the second point s2 can perform the same role as a resistor on the equivalent circuit. Therefore, the voltage of pouch 111 can maintain a value within a certain range regardless of charging or discharging of the battery cell 110. Here, the certain range may correspond to the previously defined range a. That is, the voltage of pouch 111 may be varied within the previously defined range a during battery charging or discharging. According to the embodiment, the previously defined range a may be from 0[V] to 0.5[V].

[0060] Figure 4 is a graph showing the pouch voltage of a battery cell when the battery cell is in an abnormal state according to one embodiment disclosed in this document.

[0061] Referring to Figure 4, the voltage of pouch 111 may fall outside the previously set range a depending on the state of the battery cell 110. If the insulation of pouch 111 of the battery cell 110 is broken, pouch 111 may come into contact with the electrolyte inside pouch 111. According to the embodiment, pouch 111 includes an aluminum layer, and the voltage at the second point s2 may be affected by the electrolyte when the aluminum layer comes into contact with the electrolyte. As a result, the second point s2 can perform the same role as a voltage source on the equivalent circuit. That is, the voltage at the second point s2 changes, and the voltage of pouch 111, which is the voltage between the first point s1 and the second point s2, may also change.

[0062] Specifically, when measuring the voltage of pouch 111 during the charging of battery cell 110 after dielectric breakdown, the voltage of pouch 111 may fall outside the previously set range a. In this case, the voltage of pouch 111 may be defined as the first voltage V12. Due to dielectric breakdown of the battery cell 110, a short circuit occurs between pouch 111 and the electrolyte inside pouch 111, and the voltage at the second point s2 may increase relative to the voltage at the first point s1 due to the influence of the electrolyte. As a result, the voltage of pouch 111, which is the voltage difference between the second point s2 and the first point s1, increases and may fall outside the previously set range a. That is, the first voltage V12 may fall outside the previously set range a. According to the embodiment, the first voltage V12 may have a value of 0.5[V] or more.

[0063] When measuring the voltage of pouch 111 during the discharge of battery cell 110 after dielectric breakdown, the voltage of pouch 111 may fall outside the previously set range a. In this case, the voltage of pouch 111 may be defined as the second voltage V12. Due to dielectric breakdown of battery cell 110, a short circuit occurs between pouch 111 and the electrolyte inside pouch 111, and the voltage at the second point s2 may decrease compared to the voltage at the first point s1 due to the influence of the electrolyte. As a result, the voltage of pouch 111, which is the voltage difference between the second point s2 and the first point s1, decreases and may fall outside the previously set range a. That is, the second voltage V12 may fall outside the previously set range a. According to the embodiment, the second voltage V12 may have a value less than 0[V].

[0064] Figure 5 is a graph showing the inflow current due to the pouch voltage in the charged state of a battery cell according to one embodiment disclosed in this document.

[0065] Referring to Figure 5, when charging the battery cell 110, the incoming current may be generated based on the voltage of the pouch 111. In the graph shown in Figure 5, the horizontal axis may correspond to the voltage of the pouch 111, and the vertical axis may correspond to the incoming current.

[0066] If the voltage of pouch 111 is within a previously set range a, transistor 121 may be in the OFF state. In this case, the magnitude of the incoming current may be constant. According to the embodiment, if transistor 121 is in the OFF state, the magnitude of the incoming current may be less than or equal to a previously set value.

[0067] The controller 210 can determine that the state of the battery cell 110 is normal if the magnitude of the incoming current is less than or equal to a previously set value. According to the embodiment, the controller 210 can determine that the insulation state of the battery cell 110 is normal if the magnitude of the incoming current is less than or equal to a previously set value.

[0068] If the voltage of pouch 111 falls outside the previously set range a, transistor 121 may be turned on. The voltage at the second point s2 rises due to the effect of the electrolyte, which increases the voltage difference between the second point s2 and the first point s1, causing the voltage of pouch 111 to rise. Therefore, as the voltage of pouch 111 falls outside the previously set range a and transistor 121 is turned on, a positive inflow current may occur. Here, the positive inflow current can mean the current that flows from pouch 111 through the connection part 120 to the first terminal 112.

[0069] The controller 210 can determine that the state of the battery cell 110 is abnormal if the magnitude of the positive inflow current exceeds a previously set value. In other words, the controller 210 can determine the state of the battery cell 110 based on the magnitude of the inflow current. According to the embodiment, if the magnitude of the inflow current is greater than or equal to a previously set value, the controller 210 can determine that the insulation state of the battery cell 110 is in a dielectric breakdown state.

[0070] In another embodiment, the controller 210 can also determine the state of the battery cell 110 based on the magnitude of the rate of change of the incoming current. In this case, the controller 210 can determine that the state of the battery cell 110 is abnormal if the magnitude of the derivative of the incoming current is greater than or equal to a previously set value.

[0071] If the controller 210 determines that a battery cell 110 is in an dielectric breakdown state, it can transmit information about the battery cell 110 to the user. This information may include the battery cell 110's identification number, insulation state, and the magnitude of the incoming current.

[0072] The controller 210 can shut off the battery cell 110 that has been determined to be in a dielectric breakdown state. According to the embodiment, the controller 210 can electrically isolate the battery cell 110 that has been determined to be in a dielectric breakdown state from the additional battery cell by opening a switch (not shown) that connects the battery cell 110 that has been determined to be in a dielectric breakdown state to the additional battery cell. Here, the additional battery cell can mean the other battery cells 110 among the multiple battery cells 100, excluding the battery cell 110 that has been determined to be in a dielectric breakdown state.

[0073] Figure 6 is a graph showing the inflow current due to the pouch voltage in the discharge state of a battery cell according to one embodiment disclosed in this document.

[0074] Referring to Figure 6, when the battery cell 110 is discharged, the incoming current may be generated based on the voltage of the pouch 111. In the graph shown in Figure 6, the horizontal axis may correspond to the voltage of the pouch 111, and the vertical axis may correspond to the incoming current.

[0075] If the voltage of pouch 111 is within a previously set range a, transistor 121 may be in the OFF state. In this case, the magnitude of the incoming current may be constant. According to the embodiment, when transistor 121 is in the OFF state, the magnitude of the incoming current may be less than or equal to a previously set value.

[0076] The controller 210 can determine that the state of the battery cell 110 is normal if the magnitude of the incoming current is less than or equal to a previously set value. According to the embodiment, the controller 210 can determine that the insulation state of the battery cell 110 is normal if the magnitude of the incoming current is less than or equal to a previously set value.

[0077] If the voltage of pouch 111 falls outside the previously set range a, transistor 121 may be turned on. The voltage at the second point s2 decreases due to the effect of the electrolyte, and as a result, the voltage at the second point s2 becomes smaller than the voltage at the first point s1, allowing the voltage of pouch 111 to fall outside the previously set range. This may cause transistor 121 to be turned on and generate a reverse inflow current. Here, the reverse inflow current can be defined as the current flowing from the first terminal 112 through the connection part 120 to pouch 111.

[0078] The controller 210 can determine that the state of the battery cell 110 is abnormal if the magnitude of the reverse inflow current exceeds a previously set value. In other words, the controller 210 can determine the state of the battery cell 110 based on the magnitude of the inflow current. According to the embodiment, if the magnitude of the inflow current is greater than or equal to a previously set value, the controller 210 can determine that the insulation state of the battery cell 110 is in a dielectric breakdown state.

[0079] In another embodiment, the controller 210 can also determine the state of the battery cell 110 based on the magnitude of the rate of change of the incoming current. In this case, the controller 210 can determine that the state of the battery cell 110 is abnormal if the magnitude of the derivative of the incoming current is greater than or equal to a previously set value.

[0080] The controller 210 can communicate the status of the battery cells 110 to the user, or shut off the battery cells 110, both when charging and when discharging.

[0081] In one embodiment, the battery pack 10 connects the first terminals 112 of each of the multiple battery cells 100 to the pouch 111 at the connection part 120, and by measuring the current at the connection part 120, it is possible to diagnose the dielectric breakdown of each battery cell 110 contained in the battery pack 10. In other words, the battery pack 10 can diagnose the state of each of the multiple battery cells 100 contained in the battery pack 10 based on the current at the connection part 120 during charging or discharging of the battery pack 10, without the need to destroy or disassemble the battery pack 10 separately. Furthermore, by diagnosing the state of the battery cells 110 simultaneously with charging and discharging the battery pack 10, the battery pack 10 can immediately shut off battery cells 110 that have suffered dielectric breakdown due to charging or discharging of the battery pack 10, or transmit an alarm to the user to enable immediate action. This makes it possible to prevent overheating, explosion, etc., caused by continued charging or discharging of battery cells 110 in a dielectric breakdown state.

[0082] Figure 7 is a flowchart illustrating a battery diagnostic method according to one embodiment disclosed in this document.

[0083] The embodiment shown in Figure 7 is only one embodiment, and the sequence of operations in various embodiments of the present invention may differ from that shown in Figure 7. Some steps shown in Figure 7 may be omitted, the order of steps may be changed, or steps may be merged.

[0084] Referring to Figure 7, the battery diagnostic method may include the following steps: connecting the first terminal 112 of the battery cell 110, which includes a pouch 111 covering the positive and negative electrode materials, and the first terminal 112 and second terminals 113, to the pouch 111 with a transistor 121 (S100); measuring the magnitude of the current flowing from the first terminal 112 or pouch 111 to the transistor 121 during charging or discharging of the battery cell 110 (S200); determining whether the magnitude of the current flowing into the transistor 121 is greater than or equal to a previously set current value (S300); determining that the battery cell 110 is normal (S400); shutting off the battery cell 110 (S500); and communicating an alarm regarding dielectric breakdown of the battery cell 110 to the user (S600).

[0085] The operations S100 to S600 described above will be explained in detail below with reference to Figures 1 to 6.

[0086] In operation S100, the battery pack 10 may be configured such that a pouch 111, which is configured to cover the positive electrode material and the negative electrode material, and a transistor 121 connects the first terminal 112 of a battery cell 110, which includes a first terminal 112 and a second terminal 113, to the pouch 111. According to one embodiment, the battery pack 10 may include a transistor 121, which may be configured to connect each of the first terminals 112 of the battery cell 110 to the pouch 111, or to connect the first terminal 112 to a conductive portion 114 located on the pouch 111. According to one embodiment, the first terminal 112 of each battery cell 110, the transistor 121, and the pouch 111 may be connected during the manufacturing process of the battery pack 10.

[0087] In operation S200, the battery pack 10 can measure the magnitude of the current flowing from the first terminal 112 or the pouch 111 to the transistor 121 during the charging or discharging of the battery cell 110. The battery pack 10 can also measure the magnitude of the current flowing from the pouch 111 to the connection part 120 due to the voltage of the pouch 111 during the charging or discharging of the battery pack 10, or from the first terminal 112 to the connection part 120.

[0088] In operation S300, the battery pack 10 can determine whether the magnitude of the current flowing into the transistor 121 is greater than or equal to a previously set current value. If the magnitude of the incoming current is greater than or equal to the previously set current value, the battery pack 10 can perform operation S500. If the magnitude of the incoming current is less than the previously set current value, the battery pack 10 can perform operation S400. According to this embodiment, the battery pack 10 can also determine the state of the battery cell 110 based on the magnitude of the rate of change of the incoming current. That is, in this case, the battery pack 10 can perform operation S500 if the magnitude of the rate of change of the incoming current is greater than or equal to a previously set value, and can perform operation S400 if the magnitude of the rate of change of the incoming current is less than the previously set value.

[0089] In operation S400, the battery pack 10 can determine that the battery cell 110 is functioning normally. The battery pack 10 can determine that the insulation state of the battery cell 110 is normal.

[0090] In operation S500, the battery pack 10 can disconnect the battery cell 110. The battery pack 10 can determine that the state of the battery cell 110 is in a dielectric breakdown state. According to the embodiment, the battery pack 10 can open a switch (not shown) that connects the battery cell 110 determined to be in a dielectric breakdown state to an additional battery cell, thereby electrically isolating the battery cell 110 determined to be in a dielectric breakdown state from the additional battery cell. Here, the additional battery cell can mean the other battery cells 110 among the multiple battery cells 100, excluding the battery cell 110 determined to be in a dielectric breakdown state.

[0091] In operation S600, the battery pack 10 can transmit an alarm to the user regarding dielectric breakdown of a battery cell 110. The battery pack 10 can be configured to transmit information about the battery cell 110 to the user if it determines that the battery cell 110 is in a dielectric breakdown state. For example, the battery pack 10 can be configured to provide information about the abnormal battery cell 110 not only to the user terminal via a communication unit (not shown), but also via a display provided in the vehicle or charger. Here, the information about the battery cell 110 may include the identification number of the battery cell 110, its insulation state, the magnitude of the incoming current, etc.

[0092] Figure 8 is a block diagram showing a computer system that performs a battery diagnostic method according to one embodiment disclosed in this document.

[0093] Referring to Figure 8, the computer system 500 according to one embodiment disclosed in this document may include an MCU 510, a memory 520, an input / output interface 530, and a communication interface 540.

[0094] The MCU510 may be a processor that executes various programs stored in the memory 520 (for example, a SOH calculation program, a cell balancing target determination program, etc.), processes various data including SOC and SOH of multiple battery cells through such programs, and performs the functions of the battery pack 10 as described above with reference to Figures 1 to 6.

[0095] Memory 520 can be configured to store various programs related to calculating the State of Health (SOH) of battery cells and determining which cells are eligible for cell balancing. Memory 520 can also be configured to store various data, such as the State of Charge (SOC) and SOH data for each battery cell.

[0096] Multiple such memory 520s may be provided as needed. The memory 520 may be volatile or non-volatile. For volatile memory, RAM, DRAM, SRAM, etc., may be used. For non-volatile memory, ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc., may be used. The examples of memory 520 listed above are merely illustrative and the system is not limited to these examples.

[0097] The Input / Output I / F 530 can provide an interface that connects input devices (not shown), such as keyboards, mice, and touch panels, and output devices (not shown), such as displays, to the MCU 510, enabling data transmission and reception.

[0098] The communication interface 540 is configured to send and receive various data with the server and may be various devices capable of supporting wired or wireless communication. For example, programs for calculating the State of Health (SOH) of battery cells and determining which cells are to be balanced, as well as various other data, can be sent and received from an external server separately provided via the communication interface 540.

[0099] Thus, the battery diagnostic method according to one embodiment disclosed in this document can be recorded in memory 520 and executed by MCU 510.

[0100] The above explanation is merely illustrative in describing the technical concept disclosed in this document, and a person with ordinary skill in the art to which the embodiments disclosed in this document belong could make various modifications and variations, provided that they do not deviate from the essential characteristics of the embodiments disclosed in this document.

[0101] Therefore, the embodiments disclosed herein are for illustrative purposes only, and not to limit the technical concept disclosed herein, and such embodiments do not limit the scope of the technical concept disclosed herein. The scope of protection of the technical concept disclosed herein shall be interpreted in accordance with the following claims, and all technical concepts within an equivalent scope shall be interpreted as being included in the scope of rights of this document. [Explanation of Symbols]

[0102] 10: Battery Pack 100: Multiple battery cells 110: Battery cell 120: Connection part 121: Transistor 210: Controller

Claims

1. A battery cell comprising a pouch configured to cover a positive electrode material and a negative electrode material, and a first terminal and a second terminal; A connector including a transistor configured to connect the pouch and the first terminal; A battery pack including a controller configured to measure the incoming current flowing into the connection and to diagnose the state of the battery cells based on the incoming current.

2. The battery pack according to claim 1, wherein the transistor is configured to turn on when the voltage across the connection falls outside a previously set range.

3. The battery pack according to claim 2, wherein when the transistor is turned on while the battery cell is being charged, current flows from the connection to the first terminal.

4. The battery pack according to claim 2, wherein, when the battery cell is being charged, the voltage at the point where the connection portion contacts the pouch is greater than the voltage at the point where the connection portion contacts the first terminal.

5. The battery pack according to claim 2, wherein when the transistor is turned on during the discharge of the battery cell, current flows from the connection to the pouch.

6. The battery pack according to claim 2, wherein when the battery cell is discharging, the voltage at the point where the connection portion contacts the pouch is smaller than the voltage at the point where the connection portion contacts the first terminal.

7. The battery pack according to claim 2, wherein the previously set range is set based on the voltage difference between the first terminal and the second terminal.

8. The pouch further includes a conductive portion disposed on one surface of the pouch, The battery pack according to claim 1, wherein the connection portion is configured to connect the first terminal and the pouch.

9. The controller, if the magnitude of the incoming current is greater than or equal to a previously set value, The battery pack according to claim 1, configured to determine that the battery cell is in a state of dielectric breakdown.

10. Further includes an additional battery cell electrically connected to the aforementioned battery cell, The battery pack according to claim 9, wherein the controller is configured to electrically isolate the battery cell from the additional battery cell and shut off the battery cell.

11. The battery pack according to claim 10, wherein the controller is configured to communicate an alarm to the user regarding dielectric breakdown of the battery cells.

12. A step of connecting a pouch configured to cover a positive electrode material and a negative electrode material, and the first terminal of a battery cell including a first terminal and a second terminal, to the pouch with a transistor; A step of measuring the current flowing into the transistor; and A battery diagnostic method comprising the step of diagnosing the state of the battery cell based on the inflow current flowing into the transistor.

13. The diagnostic step is performed if the magnitude of the current flowing into the transistor is greater than or equal to a previously set value. The battery diagnostic method according to claim 12, further comprising the step of determining that the battery cell has undergone dielectric breakdown.

14. The battery diagnostic method according to claim 13, further comprising the step of electrically isolating the battery cell from any additional battery cells electrically connected to it, thereby shutting off the battery cell, after the diagnostic step.

15. The battery diagnostic method according to claim 14, further comprising the step of communicating an alarm regarding dielectric breakdown of the battery cell to the user after the shut-off step.

16. The battery diagnostic method according to claim 12, wherein the transistor is turned on when the voltage across the transistor falls outside a previously set range.

17. When the battery cell is being charged, the voltage at the point where the transistor contacts the pouch is greater than the voltage at the point where the transistor contacts the first terminal. The battery diagnostic method according to claim 16, wherein when the transistor is turned on, current flows from the transistor to the first terminal.

18. When the battery cell is discharging, the voltage at the point where the transistor contacts the pouch is smaller than the voltage at the point where the transistor contacts the first terminal. The battery diagnostic method according to claim 16, wherein when the transistor is turned on, current flows from the transistor to the pouch.

19. The battery diagnostic method according to claim 16, wherein the previously set range is set based on the voltage difference between the first terminal and the second terminal.

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